ML072070623

NOAA Technical Memorandum NMFS-NE-151: Essential Fish Habitat Source Document: Summer Flounder, Paralichthys Dentatus, Life History and Habitat Characteristics

ML072070623
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Site:	Oyster Creek
Issue date:	09/30/1999
From:	Berrien P, Griesbach S, Dante Johnson, Morse W, Packer D, Zetlin C US Dept of Commerce, National Marine Fisheries Service, US Dept of Commerce, National Oceanographic and Atmospheric Administration
To:	Office of Nuclear Reactor Regulation
Davis J NRR/DLR/REBB, 415-3835
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NMFS-NE-151
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NOAA Technical Memorandum NMFS-NE-151 Essential Fish Habitat Source Document:

Summer Flounder, Paralichthys dentatus, Life History and Habitat Characteristics U. S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service Northeast Region Northeast Fisheries Science Center Woods Hole, Massachusetts September 1999

Recent Issues 105.

Review of American Lobster (Homarus americanus) Habitat Requirements and Responses to Contaminant Exposures.

By Renee Mercaldo-Allen and Catherine A. Kuropat. July 1994. v + 52 p., 29 tables. NTIS Access. No. PB96-115555.

106. Selected Living Resources, Habitat Conditions, and Human Perturbations of the Gulf of Maine: Environmental and Ecological Considerations for Fishery Management.. By Richard W. Langton, John B. Pearce, and Jon A. Gibson, eds.

August 1994. iv + 70 p., 2 figs., 6 tables. NTIS Access. No. PB95-270906.

107. Invertebrate Neoplasia: Initiation and Promotion Mechanisms -- Proceedings of an International Workshop, 23 June 1992, Washington, D.C. By A. Rosenfield, F.G. Kern, and B.J. Keller, comps. & eds. September 1994. v + 31 p., 8 figs.,

3 tables. NTIS Access. No. PB96-164801.

108. Status of Fishery Resources off the Northeastern United States for 1994. By Conservation and Utilization Division, Northeast Fisheries Science Center. January 1995. iv + 140 p., 71 figs., 75 tables. NTIS Access. No. PB95-263414.

109. Proceedings ofthe Symposium on the Potential for Development of Aquaculture in Massachusetts: 15-17 February 1995, Chatham/EdgartownfDartmouth, Massachusetts. By Carlos A. Castro and Scott J. Soares, comps. & eds. January 1996.

v + 26 p., 1 fig., 2 tables. NTIS Access. No. PB97-103782.

110. Length-Length and Length-Weight Relationships for 13 Shark Species from the Western North Atlantic. By Nancy E.

Kohler, John G. Casey, Patricia A. Turner. May 1996. iv + 22 p., 4 figs., 15 tables. NTIS Access. No. PB97-135032.

111.

Review and Evaluation of the 1994 Experimental Fishery in Closed Area II on Georges Bank. By Patricia A. Gerrior, Fredric M. Serchuk, Kathleen C. Mays, John F. Kenney, and Peter D. Colosi. October 1996. v + 52 p., 24 figs., 20 tables. NTIS Access. No. PB98-119159.

112. Data Description and Statistical Summary of the 1983-92 Cost-Earnings Data Base for Northeast U.S. Commercial Fishing Vessels: A Guide to Understanding and Use of the Data Base. By Amy B. Gautam and Andrew W. Kitts. December 1996. v + 21 p., I I figs., 14 tables. NTIS Access. No. PB97-169320.

113.

Individual Vessel Behavior in the Northeast Otter Trawl Fleet during 1982-92. By Barbara Pollard Rountree. August 199T v + 50 p., 1 fig., 40 tables. NTIS Access. No. PB99-169997.

114. U.S. Atlantic and Gulfof Mexico Marine Mammal Stock Assessments -- 1996. By Gordon T. Waring, Debra L. Palka, Keith D. Mullin, James H.W. Hain, Larry J. Hansen, and Kathryn D. Bisack. October 1997. viii + 250 p., 42 figs., 47 tables. NTIS Access. No. PB98-112345.

115. Status of Fishery Resources off the Northeastern United States for 1998. By Stephen H. Clark, ed. September 1998. vi

+ 149 p., 70 figs., 80 tables. NTIS Access. No. PB99-129694.

116.

U.S. Atlantic Marine Mammal Stock Assessments-- 1998. By Gordon T. Waring, Debra L. Palka, Phillip J. Clapham, Steven Swartz, Marjorie C. Rossman, Timothy V.N. Cole, Kathryn D. Bisack, and Larry J. Hansen. February 1999. vii + 182 p., 16 figs., 56 tables. NTIS Access. No. PB99-134140.

117.

Review of Distribution of the Long-finned Pilot Whale (Globicephala melas) in the North Atlantic and Mediterranean.

By Alan A. Abend and Tim D. Smith. April 1999. vi + 22 p., 14 figs., 3 tables. NTIS Access. No. PB99-165029.

118. Tautog (Tautoga onifis) Life History and Habitat Requirements. By Frank W. Steimle and Patricia A. Shaheen. May 1999.

vi + 23 p., 1 fig., I table. NTIS Access. No. PB99-16501 1.

119. Data Needs for Economic Analysis of Fishery Management Regulations. By Andrew W. Kitts and Scott R. Steinback.

August 1999. iv + 48 p., 10 figs., 22 tables. NTIS Access. No. PB99-171456.

120. Marine Mammal Research Program of the Northeast Fisheries Science Center during 1990-95. By Janeen M. Quintal and Tim D. Smith. September 1999. v + 28 p., 4 tables, 4 app. NTIS Access. No. PB2000-100809.

C-pArMOS 7"o~M N T OfC 0

NOAA Technical Memorandum NMFS-NE-151 This series represents a secondary level of scientifiic publishing. All issues employ thorough internal scientific review; some issues employ external scientific review.

Reviews are -- by design -- transparent collegial reviews, not anonymous peer reviews.

All issues may be cited in formal scientific communications.

Essential Fish Habitat Source Document:

Summer Flounder, Paralichthys dentatus, Life History and Habitat Characteristics David B. Packer, Sara J. Griesbach, Peter L. Berrien, Christine A. Zetlin, Donna L. Johnson, and Wallace W. Morse National Marine Fisheries Serv., James J. Howard Marine Sciences Lab., 74 Magruder Rd., Highlands, NJ 07732 U. S. DEPARTMENT OF COMMERCE William Daley, Secretary National Oceanic and Atmospheric Administration D. James Baker, Administrator National Marine Fisheries Service Penelope D. Dalton, Assistant Administrator for Fisheries Northeast Region Northeast Fisheries Science Center Woods Hole, Massachusetts September 1999

Editorial Notes on Issues 122-152 in the NOAA Technical Memorandum NMFS-NE Series Editorial Production For Issues 122-152, staff of the Northeast Fisheries Science Center's (NEFSC's) Ecosystems Processes Division have largely assumed the role of staff of the NEFSC's Editorial Office for technical and copy editing, type composition, and page layout. Other than the four covers (inside and outside, front and back) and first two preliminary pages, all preprinting editorial production has been performed by, and all credit for such production rightfully belongs to, the authors and acknowledgees of each issue, as well as those noted below in "Special Acknowledgments."

Special Acknowledgments David B. Packer, Sara J. Griesbach, and Luca M. Cargnelli coordinated virtually all aspects of the preprinting editorial production, as well as performed virtually all technical and copy editing, type composition, and page layout, of Issues 122-152. Rande R. Cross, Claire L. Steimle, and Judy D. Berrien conducted the literature searching, citation checking, and bibliographic styling for Issues 122-152. Joseph J. Vitaliano produced all of the food habits figures in Issues 122-152.

Internet Availability Issues 122-152 are being copublished, i.e., both as paper copies and as web postings. All web postings are, or will soon be, available at: www.nefsc.nmfs.gov/nefsc/habitat/ejh. Also, all web postings will be in "PDF" format.

Information Updating By federal regulation, all information specific to Issues 122-152 must be updated at least every five years. All official updates will appear in the web postings. Paper copies will be reissued only when and if new information associated with Issues 122-152 is significant enough to warrant a reprinting of a given issue. All updated and/or reprinted issues will retain the original issue number, but bear a "Revised (Month Year)" label.

Species Names The NMFS Northeast Region's policy on the use of species names in all technical communications is generally to follow the American Fisheries Society's lists of scientific and common names for fishes (i.e., Robinsetal. 199 1 a), mollusks (i.e.,

Turgeon et al. 19 9 8b), and decapod crustaceans (i.e., Williams et al. 1989c), and to follow the Society for Marine Mammalogy's guidance on scientific and common names for marine mammals (i.e., Rice 19 9 8d). Exceptions to this policy occur when there are subsequent compelling revisions in the classifications of species, resulting in changes in the names of species (e.g., Cooper and Chapleau 1998').

'Robins, C.R. (chair); Bailey, R.M.; Bond, C.E.; Brooker, J.R.; Lachner, E.A.; Lea, R.N.; Scott, W.B. 1991. Common and scientific names of fishes from the United States and Canada. 5th ed. Amer. Fish. Soc. Spec. Publ. 20; 183 p.

'Turgeon, D.D. (chair); Quinn, J.F., Jr.; Bogan, A.E.; Coan, E.V.; Hochberg, F.G.; Lyons, W.G.; Mikkelsen, P.M.; Neves, R.J.; Roper, C.F.E.;

Rosenberg, G.; Roth, B.; Scheltema, A.; Thompson, F.G.; Vecchione, M.; Williams, J.D.

1998. Common and scientific names of aquatic invertebrates from the United States and Canada: mollusks. 2nd ed. Amer. Fish. Soc. Spec. Publ. 26; 526 p.

'Williams, A.B. (chair); Abele, L.G.; Felder, D.L.; Hobbs, H.H., Jr.; Manning, R.B.; McLaughlin, P.A.; Pdrez Farfante, 1. 1989. Common and scientific names of aquatic invertebrates from the United States and Canada: decapod crustaceans. Amer. Fish. Soc. Spec. Publ. 17; 77 p.

'Rice, D.W. 1998. Marine mammals of the world: systematics and distribution. Soc. Mar. Mammal. Spec. Publ. 4; 231 p.

'Cooper, J.A.; Chapleau, F. 1998. Monophyly and interrelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification.

Fish. Butl. (U.S.) 96:686-726.

Page iii FOREWORD One of the greatest long-term threats to the viability of commercial and recreational fisheries is the continuing loss of marine, estuarine, and other aquatic habitats.

Magnuson-Stevens Fishery Conservation and Management Act (October 11, 1996)

The long-term viability of living marine resources depends on protection of their habitat.

NMFS Strategic Plan for Fisheries Research (February 1998)

The Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA), which was reauthorized and amended by the Sustainable Fisheries Act (1996),

requires the eight regional fishery management councils to describe and identify essential fish habitat (EFH) in their respective regions, to specify actions to conserve and enhance that EFH, and to minimize the adverse effects of fishing on EFH. Congress defined EFH as "those waters and substrate necessary to fish for spawning, breeding, feeding or growth to maturity." The MSFCMA requires NMFS to assist the regional fishery management councils in the implementation of EFH in their respective fishery management plans.

NMFS has taken a broad view of habitat as the area used by fish throughout their life cycle. Fish use habitat for spawning, feeding, nursery, migration, and shelter, but most habitats provide only a subset of these functions.

Fish may change habitats with changes in life history stage, seasonal and geographic distributions, abundance, and interactions with other species. The type of habitat, as well as its attributes and functions, are important for sustaining the production of managed species.

The Northeast Fisheries Science Center compiled the available information on the distribution, abundance, and habitat requirements for each of the species managed by the New England and Mid-Atlantic Fishery Management Councils. That information is presented in this series of 30 EFH species reports (plus one consolidated methods report). The EFH species reports comprise a survey of the important literature as well as original analyses of fishery-JAMES J. HOWARD MARINE SCIENCES LABORATORY HIGHLANDS, NEW JERSEY SEPTEMBER 1999 independent data sets from NMFS and several coastal states.

The species reports are also the source for the current EFH designations by the New England and Mid-Atlantic Fishery Minagement

Councils, and have understandably begun to be referred to as the "EFH source documents."

NMFS provided guidance to the regional fishery management councils for identifying and describing EFH of their managed species. Consistent with this guidance, the species reports present information on current and historic stock sizes, geographic range, and the period and location of major life history stages.

The habitats of managed species are described by the physical, chemical, and biological components of the ecosystem where the species occur. Information on the habitat requirements is provided for each life history stage, and it includes, where available, habitat and environmental variables that control or limit distribution, abundance, growth, reproduction, mortality, and productivity.

Identifying and describing EFH are the first steps in the process of protecting, conserving, and enhancing essential habitats of the managed species.

Ultimately, NMFS, the regional fishery management councils, fishing participants, Federal and state agencies, and other organizations will have to cooperate to achieve the habitat goals established by the MSFCMA.

A historical note: the EFH species reports effectively recommence a series of reports published by the NMFS Sandy Hook (New Jersey) Laboratory (now formally known as the James J.

Howard Marine Sciences Laboratory) from 1977 to 1982.

These reports, which were formally labeled as Sandy Hook Laboratory Technical Series Reports, but informally known as "Sandy Hook Bluebooks," summarized biological and fisheries data for 18 economically important species. The fact that the bluebooks continue to be used two decades after their publication persuaded us to make their successors - the 30 EFH source documents - available to the public through publication in the NOAA Technical Memorandum NMFS-NE series.

JEFFREY N. CROSS, CHIEF ECOSYSTEMS PROCESSES DIVISION NORTHEAST FISHERIES SCIENCE CENTER

Page V Contents Introduction.......................................................................................................................................................................

L ife H istory and G eographical D istribution................................................................................................................................

............. 1 Habitat Characteristics....................................................................................................................

8 S tatu s o f th e S to ck s.............................................................

20........

2 0 R e se arc h N e ed s.......................................................

2 0 A c k n o w le d g m e n ts......................... :.........................................................................................................................................................

2 1 R e fe re n c e s C ite d...........................................................................................................................

2 1 Tables Table 1. Presence of summer flounder inshore, by State, as documented by authors cited in the text and personal communications....29 Table 2. Habitat parameters for summer flounder, Paralichthys dentatus: inshore New Jersey......................................................

32 Table 3. Habitat parameters for summer flounder, Paralichthys dentatus: inshore Delaware.....

....................... 34 Table 4. Habitat parameters for summer flounder, Paralichthys dentatus: inshore North Carolina........................

36 Table 5. Summary of life history and habitat parameters for summer flounder: inshore New Jersey, Delaware and North Carolina..... 40 T able 6. Sum m er fl ounder catch and status............................................................................................................................................

42 Figures Figure 1. The summer flounder, Paralichthys dentatus (from Goode 1884)........................................................................................

43 Figure 2. Overall distribution of adult and juvenile summer flounder in NEFSC bottom trawl surveys.........................................

44 Figure 3. Distribution and abundance of juvenile and adult summer flounder collected during NEFSC bottom trawl surveys........... 45 Figure 4. Seasonal abundance of adult summer flounder relative to water depth based on NEFSC bottom trawl surveys........

47 Figure 5. Distribution and abundance of adult summer flounder in Massachusetts coastal waters...............................................

48 Figure 6. Seasonal distribution and relative abundance of adult summer flounder collected in Narragansett Bay.........................

49 Figure 7. Seasonal length frequencies of summer flounder caught in Narragansett Bay..............................

50 Figure 8. Seasonal abundance of adult summer flounder relative to bottom depth based on Narragansett Bay trawl surveys............. 51 Figure 9. Distribution and abundance of juvenile and adult summer flounder collected in Long Island Sound...............

52 Figure 10. Length frequency distribution of juvenile and adult summer flounder collected in Long Island Sound..........................

53 Figure 11. Distribution and relative abundance of adult summer flounder collected in the Hudson-Raritan estuary........................

54 Figure 12. Length-frequency distributions of juvenile and adult summer flounder from Newark Bay, New Jersey.........................

55 Figure 13. Distribution and abundance of juvenile and adult summer flounder in Pamlico Sound, North Carolina.............................. 56 Figure 14. Distribution and abundance of summer flounder eggs collected during NEFSC MARMAP surveys.............................

58 Figure 15. Monthly abundance of summer flounder eggs by region from NEFSC MARMAP surveys...........................................

60 Figure 16. Abundance of summer flounder eggs relative to water depth based on NEFSC MARMAP surveys.............................

61 Figure 17. Distribution and abundance of summer flounder larvae collected during NEFSC MARMAP surveys.......................... 62 Figure 18. Monthly abundance of summer flounder larvae by region from NEFSC MARMAP surveys.........................................

65 Figure 19. Abundance of summer flounder larvae relative to water depth based on NEFSC MARMAP surveys.............................

66 Figure 20. Classification of the transformation stages of summer flounder based on degree of eye migration...............................

67 Figure 21. Length frequency distributions for transforming larvae and juveniles collected from Charleston Harbor marsh creeks....... 68 Figure 22. Distribution and abundance of juvenile summer flounder in Massachusetts coastal waters...........................................

69 Figure 23. Seasonal abundance of juvenile summer flounder relative to water depth based on NEFSC bottom trawl surveys.............. 70 Figure 24. Distribution and relative abundance of juvenile summer flounder collected in the Hudson-Raritan estuary...................

71 Figure 25. Monthly distribution of summer flounder in the Chesapeake Bay main stem and major Virginia tributaries................ 72 Figure 26. Length frequency summary for summer flounder in the Chesapeake Bay main stem and major Virginia tributaries........... 74 Figure 27. Abundance of summer flounder eggs relative to water temperature based on NEFSC MARMAP surveys.................... 75 Figure 28. Abundance of summer flounder larvae relative to water temperature based on NEFSC MARMAP surveys...................

76 Figure 29. Seasonal abundance of juvenile summer flounder relative to bottom temperature based on NEFSC trawl surveys............. 77 Figure 30. Abundance of juvenile and adults relative to bottom temperature and depth based on Massachusetts trawl surveys........... 78 Figure 31. Abundance of juvenile summer flounder relative to salinity in four Charleston Harbor, South Carolina marsh creeks........ 79 Figure 32. Relative importance of each diet item to summer flounder from the Newport and North Rivers, North Carolina.......

80

Page vi Figure 33. Food items in the seasonal diet of young summer flounder from the Neuse River and Pamlico Sound, North Carolina...... 81 Figure 34. Seasonal abundance of adult summer flounder relative to bottom temperature based on NEFSC bottom trawl surveys...... 82 Figure 35. Seasonal abundance of adult summer flounder relative to bottom temperature based on Narragansett Bay trawl surveys...83 Figure 36. Abundance of the major prey items in the diet of summer flounder collected during NEFSC bottom trawl surveys........... 84 Figure 37. Commercial landings, NEFSC survey indices, and stock biomass for Georges Bank and Mid-Atlantic summer flounder..86 Figure 38. Distribution and abundance of adult and juvenile summer flounder during high and low abundance periods................ 87

Page 1 INTRODUCTION The geographical range of the summer flounder or fluke, Paralichthys dentatus (Figure 1), encompasses the shallow estuarine waters and outer continental shelf from Nova Scotia to Florida (Ginsburg 1952; Bigelow and Schroeder 1953; Anderson and Gehringer 1965; Leim and Scott 1966; Gutherz 1967; Gilbert 1986; Grimes et al.

1989), although Briggs (1958) gives their southern range as extending into the northern Gulf of Mexico. The center of its abundance lies within the Middle Atlantic Bight from Cape Cod, Massachusetts, to Cape Hatteras, North Carolina (Figure 2; Hildebrand and Schroeder 1928). North of Cape Cod and south of Cape Fear, North Carolina, summer flounder numbers begin to diminish rapidly (Grosslein and Azarovitz 1982). South of Virginia, two closely related species, the southern flounder (Paralichthys lethostigma) and the gulf flounder (Paralichthys albigutta) occur and sometimes are not distinguished from summer flounder (Hildebrand and Cable 1930; Byme and Azarovitz 1982).

For more detailed discussions of the summer flounder's distribution on the shelf and in the various estuaries, see the Life History and Geographical Distribution section.

Summer flounder exhibit strong seasonal inshore-offshore movements, although their movements are often not as extensive as compared to other highly migratory species.

Adult and juvenile summer flounder normally inhabit shallow coastal and estuarine waters during the warmer months of the year and remain offshore during the fall and winter (Figure 3). Complete descriptions of the inshore-offshore migratory patterns of the summer flounder are in the Life History and Geographical Distribution section of this paper.

LIFE HISTORY AND GEOGRAPHICAL DISTRIBUTION STOCK STRUCTURE Several stocks of summer flounder may exist throughout its range, and numerous attempts have been made to identify them. Since a genetically distinct stock can have unique rates of recruitment, growth, and mortality (Cushing 1981),

identification of the various stocks or subpopulations of summer flounder and their stock-specific biological traits, as well as their habitat distribution and overlap, is necessary for proper management. Previous stock identification studies suggested that significant differences exist between summer flounder north and south of Cape Hatteras; i.e., between those in the Mid-Atlantic Bight and South Atlantic Bight (Wilk et al. 1980; Fogarty et al. 1983; Able et al. 1990; Wenner et al. 1990a). Summer flounder north and south of the Cape were statistically separable on the basis of morphometric characters, with apparent intermixing of northern and southern contingents in the vicinity of Cape Hatteras [tagging studies by Desfosse (1995) also indicated that there was some exchange of summer flounder between the north and south of Cape Hatteras during winter]. Thus, it was suggested that the Cape Hatteras region may form a zoogeographical barrier between the Middle and South Atlantic Bights which results in the reproductive isolation of the adjacent stocks of summer flounder (Wilk et al. 1980; Fogarty et al. 1983). This was also suggested by tagging studies in the nearshore waters and sounds north of North Carolina which showed that fish tagged north of Cape Hatteras moved northward, while fish tagged south of Hatteras moved southward (Monaghan 1992, 1996). An alternative hypothesis by Wenner et al. (1990a) suggested that, rather than two separate populations, the South Atlantic Bight may serve as a nursery area for summer flounder in the Mid-Atlantic Bight.

However, Jones and Quattro (1999) analyzed -the genetic diversity revealed in the mitochondrial DNA (mtDNA) in samples of juveniles and adult summer flounder collected from coastal sites from Buzzard's

Bay, Massachusetts to Charleston, South Carolina during 1992 to 1996. In contrast to the previous morphological studies, analyses of mtDNA variation revealed no significant population subdivision centered around Cape Hatteras; i.e.,

summer flounder populations are not genetically different north and south of Cape Hatteras. Jones and Quattro (1999) suggest that the phenotypic divergence seen among geographic samples of summer flounder (Wilk et al. 1980; Fogarty et al. 1983) may reflect differential environmental influences.

Within the Middle Atlantic Bight, Fogarty et al. (1983) reported that a summer flounder discrimination workshop was unable to examine adequately the hypothesis of multiple stocks. Although Smith (1973) identified concentrations of summer flounder eggs off Long Island, Delaware-Virginia, and North Carolina, the workshop concluded that the distribution of summer flounder eggs and larvae was continuous throughout the Middle Atlantic Bight and that the apparent concentrations identified by Smith (1973) were not the result of multiple stocks, but may have been due to sampling variability. However, Jones and Quattro (1999) did detect population genetic structure in their samples of summer flounder from the northern portion of its range; i.e.,

a small but significant portion of the total genetic variance could be attributed to differences between their Massachusetts and Rhode Island samples and all the other samples. Furthermore, tagging studies by Desfosse et al.

(1988) and Desfosse (1995) indicate that there may be two subpopulations of summer flounder in Virginia inshore waters, and studies by Van Housen (1984), Delaney (1986),

and Holland (1991),

as well as such supplemental observations as by Ross et al. (1990) off of North Carolina, suggest that inshore populations from Virginia to North Carolina may form a separate population from those to the north and offshore (a trans-Hatteras stock). Further studies from these regions will be necessary to confirm these observations.

Nonetheless, it is important to note that throughout the

Page 2 U.S. EEZ, summer flounder is managed and assessed as a single stock' by the Mid-Atlantic Fishery Management Council (NMFS 1997).

ADULTS As stated above, summer flounder exhibit strong seasonal inshore-offshore movements (Figure 3). Adult flounder normally inhabit shallow coastal and estuarine waters during the warmer months of the year and remain offshore during the colder months on the outer continental shelf at depths down to 150 m (Figure 4; Bigelow and Schroeder 1953; Grosslein and Azarovitz 1982).

Some evidence suggests that older adults may remain offshore all year (Festa 1977). However, due to overfishing, most of the adults are < 3 years of age and they return to the inner continental shelf and estuaries during the summer [Able and Kaiser 1994; Terceiro 1995; Northeast Fisheries Science Center.1997; in addition, Desfosse's (1995) study in Virginia waters notes that the majority of fish sampled from 1987-1989 were from 0-3 years of age, and over 90% of the summer flounder survey catch in Delaware Bay for 1996

.was also less than age 3 (Michels 1997)]. The southern population may undertake less extensive offshore migrations (Fogarty et al. 1983). Tagging studies indicate that fish which spend their summer in a particular bay tend largely to return to the same bay in the subsequent year or to move to the north and east (Westman and Neville 1946; Hamer and Lux 1962; Poole 1962; Murawski 1970; Lux and Nichy 1981; Monaghan 1992; Desfosse 1995).

For example, tagging studies indicate that the majority of summer flounder from inshore' New Jersey return to inshore New Jersey the following year. This homing is also evident in summer flounder which return to.New York waters, with some movement to waters off Connecticut, Rhode Island and Massachusetts (Poole 1962).

Once inshore during the summer months, there appears to be very little movement of inshore fish to offshore waters (Westman and Neville 1946; Poole 1962; Desfosse 1995).

Tagging studies conducted by Poole (1962) and Lux and Nichy (1981) on flounder released off Long Island and southern New England revealed that fish usually began seaward migrations in September or October.

Their wintering grounds are located primarily between Norfolk and Veatch Canyons east of Virginia and Rhode Island, respectively, although they are known to migrate as far northeastward as Georges Bank. Fish that move as far north as the wintering grounds north of Hudson Canyon may become rather permanent residents of the northern segment of the Mid-Atlantic Bight (Lux and Nichy 198 1). New York and New Jersey fish may move farther south in the winter months and generally may not move as far north in the summer as New England flounder (Poole 1962).

The presence, distribution, and abundance of the adults nearshore and in the estuaries has been documented by both fishery dependent and independent data and each States' flounder experts (Table 1). For example, summer flounder in Massachusetts migrate inshore in early May and occur along the entire shoal area south of Cape Cod and Buzzards Bay, Vineyard Sound, Nantucket Sound, and the coastal waters around Martha's Vineyard (Figure 5; Howe et al.

.1997). They also occur in the shoal waters in Cape Cod Bay (A.B. Howe, Massachusetts Div. of Mar. Fish., Sandwich, MA, personal communication).

In some years summer flounder are found along the eastern side of Cape Cod and as far north as Provincetown by early May.

The Massachusetts Division of Marine Fisheries considers the shoal waters of Cape Cod Bay and the region east and south of Cape Cod, including all estuaries, bays and harbors thereof, as critically important habitat (Howe, personal communication). Summer flounder begin moving offshore in late September and October and Howe (personal communication) believes that spawning occurs within territorial waters south of Cape Cod 'because occasional ripe and running fish have been taken there. Summer flounder are regularly taken in southern Massachusetts waters as late as December, presumably as fish are dispersing to offshore wintering grounds, which, in most years are well out on the continental shelf from approximately Veatch Canyon to Baltimore Canyon.

T.R. Lynch (Rhode Island Dept. of Environ. Mgmt.,

Wickford, RI, personal communication) states that the coastal waters of Rhode Island, the immediate waters surrounding Block Island, and the waters of Little Narragansett Bay and all of Narragansett Bay are habitat for both adults and juveniles. Based on collections from the 1990-1996 Rhode Island Narragansett Bay survey, adults were distributed throughout the Bay and captured in all seasons except winter and most were caught in summer and autumn (Figure 6). The length frequencies show that similar sizes were captured in each season and lengths ranged from about 25-71 cm with most occurring from 30-50 cm (Figure 7).

Abundance in relation to bottom depth shows a preference for depths greater than 12.2-15.2 m (40-50 ft) and that few were captured in depths less than 9.1 m (30 ft)

(Figure 8).

In Connecticut, E. Smith (Connecticut Dept. of Environ. Prot., Hartford, CT, personal communication) states that the flounder migrate to inshore waters in late April and early May, and are present in Long Island Sound throughout the April-November trawl survey period, and probably occur in limited numbers in winter as well (Figure 9 -- these figures include juveniles and adults, see Figure 10).

August through October are often the months of highest relative abundance (Simpson et al. 1990a, b, 1991; Gottschall et al., in review). Although they occur on all bottom types, their abundance does vary by area and depth (Gottschall et al., in review). In April, abundance is similar at all depths, but from May through August abundance is highest in shallow water, especially in depths less than 9 m along the Connecticut shore from New Haven to Niantic Bay, and near Mattituck, New York (Figure 9; Gottschall et al., in review).

In September, when abundance peaks,

Page 3 summer flounder are again distributed in all depths throughout the sound. After September, their abundance decreases, and the remaining fish are more common in deeper water. Abundance is highest in depths between 18-27 m in October and depths > 27 m in November (Gottschall et al., in review). Abundance indices within the Sound are geneially highest in the central Sound (Connecticut to Housatonic Rivers) and lowest west of the Housatonic River (Simpson et al. 1990a, b, 1991). Salinity range appears to be at least 15 ppt and greater. The trawl survey usually takes 400-700 fish in 320 tows per year. In 1989, only 47 fish were taken (D.G. Simpson, Connecticut Dept. of Environ. Prot., Waterford, CT, personal communication).

From the Marine Angler Survey, about two-thirds of the sport flounder catch is from east of the Connecticut River, while the trawl survey catches indicate that the greater New Haven area is also important.

In 'the Hudson-Raritan estuary, New York and New Jersey, summer flounder was the 13th most abundant species in the Wilk et al. (1977) survey and it occurred in 21% of all trawls and had a mean annual density in the Lower Bay complex of 1.2/15 min tow (see also reviews by Gaertner 1976 and Berg and Levinton 1985).

The 1992-1997 Hudson-Raritan surveys show the adults to be present in moderate numbers throughout the estuary in all seasons except winter (Figure 11). In the fall, they tend to be found in greater numbers in the deeper waters of the Raritan Channel (Figure I1). In the spring, the greatest numbers occurred in Sandy Hook Bay. The greatest densities of summer flounder adults occurred in the summer, particularly in the deeper Raritan and Chapel Hill channels and Raritan and Sandy Hook Bays. This species was not reported in any trawls in the Arthur Kill-Hackensack River estuary.

However, it has been collected in Newark Bay from April-October (Wilk et al. 1997; Figure 12). Great South Bay, on the south shore of Long Island, supports an important recreational fishery, particularly around Fire Island inlet (Neville etal. 1939; Schreiber 1973).

Tagging studies by Murawski (1970) provided recaptured summer flounder from the entire New Jersey coastline. Summer flounder overwinter offshore of New Jersey in 30-183 m of water. Allen et al. (1978) collected both adult and juvenile summer flounder in Hereford Inlet near Cape May.

They occurred in all of the major waterways, but were more abundant in the upper embayment from May to July and in the lower embayment from August to October.

The majority were 200-400 mm and were caught on the slopes of the channels. In Barnegat Bay, an ichthyofauna survey by Vouglitois (1983) from 1976-1980 found a wide range of sizes of summer flounder, but in low numbers.

This study was conducted along the western shoreline of the Bay, where muddy sediments predominate, and Vouglitois (1983) suggests that the scarcity of summer flounder is due to their apparent preference for sandy substrates. A hard sandy bottom does predominate in the

'eastern portion of the Bay and this is where most summer flounder have been caught.

Delaware Bay is an important nursery and summering area for adults as well as a nursery area for juveniles (R.

Smith, Delaware Dept. of Nat. Res. and Environ. Control, Dover, DE, personal communication). They are abundant in the lower and middle portions of the estuary, and rare in the upper estuary (Ichthyological Associates, Inc.

1980; Seagraves 1981; Weisberg et al. 1996; Michels 1997).

Smith and Daiber (1977) caught adults from the shoreline to a maximum depth of 25 m, mostly from May through September, while R. Smith (personal communication) states that adults have been captured in Delaware Bay during all months of the year, but appear to be most common from April to November. The Delaware Bay Coastal Finfish Assessment Survey for 1996 found adults throughout the April to December sampling period, with the highest catch rate in April and greatest occurrences at mid-bay stations (Michels 1997). Delaware's coastal bays are also used by summer flounder as nursery and summering areas [e.g.,

Indian River and Rehobeth Bays (Michels 1997)].

In Virginia adult flounder use theEastern Shore seaside lagoons and inlets and the lower Chesapeake Bay as summer feeding areas (Schwartz 1961; J.A. Musick, Virginia Inst.

Mar. Sci., Gloucester Point, VA, personal communication).

These fish usually concentrate in shallow warm water at the upper reaches of the channels and larger tidal creeks on the Eastern Shore in April, then move toward the inlets as spring and summer progress. They are most abundant in the ocean near inlets by July and August. Tagging studies by Desfosse (1995) revealed that fall migration begins out of Chesapeake Bay in October and is completed by December where most recaptures of fish were from the nearshore fishery from Cape Henry south to Cape Hatteras.

The majority of tagged returns during January through March came from offshore from the Cigar north to Wilmington Canyon, and were concentrated east of Cape Henry from the Cigar to Norfolk Canyon. A second group came from inshore waters near Oregon Inlet, south to Cape Hatteras. Movement inshore started in March or perhaps as 'early as February, and continued from April till June.

Virginia's artificial reefs also provide additional habitat for summer flounder (J. Travelstead, Virginia Mar. Res.

Comm., Hampton, VA, personal communication; see also Lucy and Barr 1994). Reef materials include discarded vessels, automobile tires, and fabricated concrete structures.

Both adults and juveniles occur in Pamlico Sound and adjacent estuaries (Figure 13), although it appears that juveniles are usually the more abundant, confirming the significant role of these estuaries as a nursery area for this species (Powell and Schwartz 1977). They occur in areas of intermediate or high salinities, often close to inlets, and prefer a sandy or sand/shell substrate (Powell and Schwartz 1977).

Several surveys have shown that both adult and juvenile summer flounder occur in small numbers in the waters of South Carolina (e.g., Bearden and Farmer 1972; Hicks 1972; Wenner et al. 1981, 1986; Stender and Martore 1990; Wenner et al. 1990a, b). Artificial reefs also provide habitat

Page 4 for summer flounder off of South Carolina (Parker et al.

1979).

Dahlberg (1972) surveyed the North and South Newport Rivers, Sapelo Sound, and the St. Catherines Sound estuarine complex in Georgia. Adult and juvenile summer flounder were most abundant in the lower reaches of the estuaries and were rarely trawled in the middle reaches.

REPRODUCTION In the Middle Atlantic Bight, Morse (1981) estimated the length at which 50% of the fish are mature (L50) is 24.6 cm for males and 32.2 cm for females. The smallest mature male was 19.1 cm and the largest immature male was 39.9 cm. Females began maturing at 24.9 cm and the largest immature female was 43.9 cm. The range of L50 for males and females indicates sexual maturity is attained by age 2 (Morse 1981; however see below). Adult females are 60 mm total length (TL) longer on average than males at first attainment of sexual maturity. The L50 also varied during the six years of Morse's (1981) study. No consistent general trend in L50 was evident as males and females appeared to exhibit independent changes. Murawski and Festa (1976) reported that the minimum size at maturity of female summer flounder sampled from off New Jersey during 1963-1964 was 37.0 cm TL, while Smith and Daiber (1977) reported that the minimum size at maturity of fish from Delaware Bay was 30.5 cm and. 36.0 cm TL for males and females, respectively.

Desfosse (1995) reported the minimum size at maturity of fish sampled from 1987-1989 in Virginia waters was 22-23 cm TL for males and 23-24 cm TL for females. The Lyo for males was 26.1-27.0 cm TL and

• 36.1-37.0 cm TL for females. Powell (1974) noted that the minimum size at maturity of summer flounder from Pamlico Sound, North Carolina was 35.0 cm TL. In the South Atlantic Bight, Wenner et al. (1990a) estimated the L5o to be 28.9 cm TL for males and 30.7 cm TL for females, corresponding to fish approaching age 2. Based on the study by O'Brien et al. (1993) on the L50 of summer flounder sampled from 1985-1989 from Nova Scotia to Cape Hatteras, this report will use the female size of 28 cm (age 2.5) as the divide between all juvenile and adult individuals. The median length at maturity for males in the O'Brien et al. (1993) study was 24.9 cm (age 2). However, as O'Brien et al. (1993) notes, a revision to aging convention (Smith et al. 1981; Almeida et al. 1992) has resulted in median lengths being attained a year earlier than those reported above; thus, for example, the ages of O'Brien et al. (1993) are also off by a year (i.e., the age 2.5 female fish are now age 1.5).

These conclusions have been supported by more recent growth studies (Able et al. 1990; Szedlmayer et al. 1992).

Fecundity and length exhibit a curvilinear relationship, but with logarithmic transformations, Morse (1981) expressed the relationship as:

loglo Fecundity = logl 0 a + b (log10 length) where the intercept (a) = -3.098 and the slope (b) = 3.402.

The relationship between fecundity and weight and ovary weight were expressed by Morse (1981) as:

Fecundity =a + bX where the intercept (aweight) = -101,865.5 and the slope (bweight)

= 908.864, and the intercept (aova weight) 52,515.161 and the slope (bovary weight) = 10,998.048.

Powell (1974) estimated that females ranging from 50.6-68.2 cm TL have 1.67-1.70 million ova per fish, while Morse (1981) reported fish between 36.6 and 68.0 cm TL have 0.46-4.19 million ova. The relative fecundity, number of eggs produced per gram of total weight of spawning female, ranged from 1,077-1,265 in Morse's (1981) study.

The increase in variability in fecundity estimates as weight increases tends to obscure the true relationship. The high egg production to body weight is. maintained by serial spawning. In fact, the weight of annual egg production, assuming an average egg diameter of 0.98 mm and 1.0 specific gravity, equals' approximately 40-50% of the biomass of spawning females (Morse 1981).

Morse (1981) calculated the percent of ovary weight to total fish weight as an index for maturity.

The mean maturity index increased rapidly from August to September,

.peaked in October-November, then gradually decreased to a low in July. The wide range in the maturity indices during the spawning season indicates nonsynichronous maturation of females and a relatively extended spawning season. The length and peak spawning timeas indicated by the maturity index agree with results determined by egg and larval occurrence (Herman 1963; Smith 1973).

Spawning occurs over the open ocean areas of the shelf (Figure 14). Summer flounder spawn during the fall and winter while the fish are moving offshore or onto their wintering grounds; the offshore migration is presumably keyed to declining water temperature and decreasing photoperiod during the autumn. The spawning migration begins near the peak of the summer flounder's gonadal development cycle, with the oldest and largest fish migrating first each year (Smith 1973).

The seasonal migratory/spawning pattern varies with latitude (Smith 1973)"; i.e., gonadal development, spawning and offshore movements occur earlier in the northern part of their range (Rogers and Van Den Avyle 1983).

For example, in Delaware Bay, gonads of summer flounder appear to ripen from mid-August through November (Smith and Daiber 1977), while peak gonadal development occurs during December and January for fish around Cape Hatteras (Powell 1974). Spawning begins in September in the inshore waters of southern New England and the Mid-Atlantic. As the season progresses, spawning moves onto Georges Bank as well as southward and eastward into deeper waters across the entire breadth of the shelf (Berrien and Sibunka 1999).

Page 5 Spawning continues through December in the northern sections of the Middle Atlantic Bight, and through February/March in the southern sections (Smith 1973; Morse 1981; Almeida et al. 1992).

Spawning peaks in October north of Chesapeake Bay and November south of the Bay (Smith 1973; Able et al. 1990; note that the latter statement on spawning south of the Bay in November appears to contradict the published information above concerning peak gonadal development occurring December-January near Cape Hatteras). The half year spawning season reduces larval crowding and decreases the impact of predators and adverse environmental conditions on egg and larval survival (Morse 1981). In the South Atlantic Bight, maturity observations by Wenner et al. (1990a) suggest that spawning begins as early as October, and may continue through February and possibly early March.

EGGS Eggs of summer flounder are pelagic and buoyant. They are spherical with a transparent, rigid shell; yolk occupies about 95% of the egg volume. Mean diameter of mature unfertilized eggs is 0.98 mm.

Eggs are most abundant between Cape Cod/Long Island and Cape Hatteras (Figures 14 and 15); the heaviest concentrations have been reported within 45 km of shore off New Jersey and New York during 1965-1966 (Smith 1973),

and from New York to Massachusetts during 1980-1986 (Able et al. 1990). Able et al. (1990) discovered that the highest frequency of occurrence and greatest abundances of eggs in the northwest Atlantic occurs in October and November (Figure 15), although, due to limited sampling in December south of New England, December could be under represented. Festa (1974) also notes an October-November spawning period off New Jersey. Keller et al. (1999) found eggs (maximum density 19.5/100 in

3) from February to June in Narragansett Bay during a December 1989 to November 1990 sampling period. In southern areas, eggs have been collected as late as January-May (Figure 14; Smith 1973; Able et al. 1990).

The eggs have been collected mostly at depths of 30-70 m in the fall, as far down as 110 m in the winter, and from 10-30 m in the spring (Figure 16).

LARVAE Planktonic larvae (2-13 mm) are often most abundant 19-83 km from shore at depths of around 10-70 m, and are found in the northern part of the Middle Atlantic Bight from September to February, and in the southern part from November to May, with peak abundances occurring in November (Smith 1973; Able et al. 1990; Figures 17, 18, 19). The smallest larvae (< 6 mm) were most abundant in the Mid-Atlantic Bight from October-December, while the largest larvae (> II mm) were abundant November-May with peaks in November-December and March-May (Able et al. 1990). Off eastern Long Island and Georges Bank, the earliest spawning and subsequent larval development occurs as early as September (Able and Kaiser 1994). By October, the larvae are primarily found on the inner continental shelf between Chesapeake Bay and Georges Bank.

During November and December they are evenly distributed over both the inner and outer portions of the shelf. By January and February the remaining larvae are primarily found on the middle and outer portions of the shelf. By April, the remaining larvae are concentrated off North Carolina (Able and Kaiser 1994).

From October to May larvae and postlarvae migrate inshore, entering coastal and estuarine nursery areas to complete transformation (Table 1; Merriman and Sclar 1952; Olney 1983; Olney and Boehlert 1988; Able et al.

1990; Szedlmayer et al. 1992).

Larval to juvenile metamorphosis, which involves the migration of the right eye across the top of the head, occurs over the approximate range of 8-18 mm SL (Burke et al. 1991; Keefe and Able 1993; Able and Kaiser 1994; Figure 20). They then leave the water column and settle to the bottom where they begin to bury in the sediment and complete development to the juvenile stage, although they may not exhibit complete burial behavior until mid-late metamorphosis when eye migration is complete, often at sizes as large as 27 mm SL (Keefe and Able 1993, 1994). However, burying behavior of metamorphic summer flounder is also significantly affected by substrate type, water temperature, time of day, tide, salinity, and presence and types of predators and prey (Keefe and Able 1994).

Keller et al. (1999) found larvae (maximum density 1.4/100 in 3 ) from September to December in Narragansett Bay during a December 1989 to November 1990 sampling period. Able et al. (1990) and Keefe and Able (1993) discovered that some transforming larvae (10-16 mm) entered New Jersey estuaries primarily during October-December, with continued ingress through April; Allen et al.

(1978) collected larvae (12-15 mm) in February and April in Hereford Inlet near Cape May. Dovel (1981) recorded 9 larvae in the lower Hudson River estuary, New York in 1972. In North Carolina, the highest densities of larvae are found in Oregon Inlet in April, while farther south in Ocracoke Inlet, the highest densities occur in February (Hettler and Barker 1993).

J.P. Monaghan, Jr. (North Carolina Dept. of Nat. Res. and Commer. Dev., Morehead City, NC, personal communication) mentions that for the years 1986-1988, peak immigration periods of larvae through Beaufort Inlet and into North Carolina estuaries were from late February through March. In the Cape Fear River Estuary, North Carolina, it has been reported that postlarvae first enter the marshes in March and April and are 9-16 mm SL during peak recruitment (Weinstein 1979; Weinstein et al. 1980b). Schwartz et al. (1979a, b) also notes that age 0 flounder appear in the Cape Fear River between March and May, depending on the year. Warlen and Burke (1990) found larvae (mean 13.1 mm SL) in the

Page 6 Newport River estuary just inside Beaufort Inlet from February-April, 1986, with peak abundance in early March.

Powell and Robbins (1998) reported larval summer flounder adjacent to live-bottom habitats (rock outcroppings containing rich invertebrate communities and many species of tropical and subtropical fishes) in Onslow Bay (near Cape Lookout) in November (at stations of 17-22 m depth),

February (28-30 m depth), and May (14-16 m and 17-22 m depth). Burke et al. (1998) conducted night-time sampling for transforming larvae and juveniles in Onslow Bay, Beaufort Inlet, and the Newport River estuary in February-March 1995. Although flounders were captured both in Onslow Bay and in the surf zone during the immigration period, densities were low and all were transforming larvae (7-15 mm SL). After the immigration period, flounders were absent, as juveniles were not caught. Within the Newport River estuary, flounders were locally very abundant as compared to within Onslow Bay and initial settlement was concentrated in the intertidal zone. During February most were transforming larvae, in March some were completely settled juveniles (11-21 mm SL). In South Carolina, Burns (1974) captured summer flounder larvae (14.9-17.5 mm) in New Bridge Creek, North Inlet estuary in February-March, while Bearden and Farmer (1972) recorded larvae and postlarvae in Port Royal Sound estuary from January-March.

During 1986-1988, Wenner et al. (I 990a) found that ingress of recently transformed larval and juvenile summer flounder (10-20 mm TL) into Charleston Harbor, South Carolina estuarine marsh creeks began in January and continued through April (Figure 21). Larvae and postlarvae were also found during this period in the Chainey Creek area (Wenner et al. 1986).

JUVENILES As stated above, juveniles are distributed inshore (e.g.,

Figure 22) and in many estuaries throughout the range of the species during spring, summer, and fall (Table 1; Deubler 1958; Pearcy and Richards 1962; Poole 1966; Miller and Jorgenson 1969; Powell and Schwartz 1977; Fogarty 1981; Rountree and Able 1992a, b, 1997; Able and Kaiser 1994; Walsh et al. 1999). During the colder months in the north there is some movement to deeper waters offshore with the adults (Figure 3; Figure 23), although many juvenile summer flounder will remain inshore through the winter months while some juveniles in southern waters may generally overwinter in bays and sounds (Smith and Daiber 1977; Wilk et al. 1977; Able and Kaiser 1994). In estuaries north of Chesapeake Bay, some juveniles remain in their estuarine habitat for about 10 to 12 months before niigrating offshore their second fall and winter; in North Carolina sounds, they often remain for 18 to 20 months (Powell and Schwartz 1977). The offshore juveniles return to the coast and bays in the spring and generally stay the entire summer.

Fogarty (1981) examined the distribution patterns of prerecruit (< 30.5 cm) summer flounder caught during the 1968-1979 spring surveys and found a striking absence of small fish in northern areas. Both spring and autumn bottom trawl survey data indicated that the concentration of young-of-year summer flounder was south of 390 latitude. The importance of the Chesapeake Bight to this species is demonstrated by the fact that almost all of the young-of-year caught during those spring surveys were from this area.

In Mid-Atlantic estuaries, first year summer flounder can grow rapidly and attain lengths of up to at least 30.0 cm (Poole 1961; Almeida et al. 1992; Szedlmayer et al. 1992).

Young-of-the-year summer flounder in New Jersey marsh creeks have average growth rates of 1.3-1.9 mm/d, and increase from about 16.0 cm TL at first appearance in late July to around 26.0 cm by September (Rountree and Able 1992b; Szedlmayer et al. 1992).

First year fish from Pamlico Sound, North Carolina obtained mean lengths of 16.7 cm for males and 17.1 cm for females (Powell 1982).

In Charleston Harbor and other South Carolina estuaries from 1986-1988, Wenner et al. (1990a) found transforming larvae were recruited into the estuarine creeks when 1-2 cm TL. Growth accelerated in May and June when they reached modal sizes of 8 and 14 cm TL, respectively.

By September, modal size was 16 cm TL and reached from 23-25 cm TL through October and November. Modal lengths of yearlings ranged from 23-25 cm in January through June and generally reached 28 cm by October. In Georgia, lab studies by Reichert and van der Veer (1991) found that juveniles from Duplin River of 28-46 mm SL had a maximum growth rate of about 1.3-1.4 mm/d at laboratory temperatures of 23.7-24.8°C.

Juvenile summer flounder make use of several different estuarine habitats. Estuarine marsh creeks are important as nursery habitat, as has been shown in New Jersey (Rountree and Able 1992b, 1997; Szedlmayer et al. 1992; Szedlmayer and Able 1993), Delaware (Malloy and Targett 1991),

Virginia (Wyanski 1990), North Carolina (Burke et al.

1991) and South Carolina (Bozeman and Dean 1980; McGovern and Wenner 1990; Wenner et al. 1990a, b).

Other portions of the estuary that are used include seagrass beds, mud flats and open bay areas (Lascara 1981; Wyanski, 1990; Szedlmayer et al. 1992; Walsh et al. 1999).

Patterns of estuarine use by the juveniles can vary with latitude. In New Jersey, nursery habitat includes estuaries and marsh creeks from Sandy Hook to Delaware Bay (Allen et al. 1978; Rountree and Able 1992a, b, 1997; Szedlmayer et al. 1992; Szedlmayer and Able 1993; B.L. Freeman, New Jersey Dept. of Environ. Prot., Trenton, NJ, personal communication). The juveniles often make extensive use of creek mouths (Szedlmayer et al. 1992; Szedlmayer and Able 1993; Rountree and Able 1997). In the Hudson-Raritan estuary, New York and New Jersey, 1992-1997 surveys show the juveniles to be present in small numbers throughout the estuary in all seasons, with slightly higher numbers seen in the spring (Figure 24).

In Great Bay, young-of-the-year stay for most of the summer, leaving as early as August and continuing until November-December (Able et al. 1990; Rountree and Able 1992a; Szedlmayer

Page 7 and Able 1992; Szedlmayer et al. 1992).

As stated previously, Allen et al. (1978) collected both adult and juvenile summer flounder (200-400 min) in Hereford Inlet near Cape May where they occurred in all of the major waterways, but were more abundant in the upper embayment from May to July and in the lower embayment from August to October. Most were caught on the channel slopes.

Smith and Daiber (1977) report that in Delaware Bay, most summer flounder were collected May through September but a few juveniles have been caught in the deeper parts of the Bay in every winter month.

The Delaware Bay Coastal Finfish Assessment Survey for 1996 found juveniles throughout their April to October sampling period (Michels 1997).

In Maryland, J.F. Casey (Maryland Dept. of Nat. Res.,

Ocean City, MD, personal communication) indicated that although the coastal bays are excellent habitat for both adults and juveniles (Schwartz 1961), in areas of significant pollution, a lack of proper food sources precludes the presence of summer flounder.

Other areas which lack sufficient water circulation also appear to have considerably reduced populations. Shore-side development and resultant runoff also appear to have reduced some local populations (Casey, personal communication).

Since the 1970's, Maryland has been conducting trawl and seine surveys around Ocean City inlet. Casey (personal communication) reported sharp declines in young-of-the-year flounder in the coastal bay trawl samples. The majority of the summer flounder taken in this sampling were between 76 and 102 mm, with larger fish basically absent. Summer flounder were also sometimes found in Maryland's portion of the Chesapeake Bay with the majority of these fish in the 200-300 mm range.

In Virginia, Musick (personal communication) states that the most important nursery areas for summer flounder appear to be in the lagoon system behind the barrier islands on the seaside of the Eastern Shore (Schwartz 1961), and the shoal water flat areas of higher salinity (> 18 ppt) in lower Chesapeake. Bay. Young-of-the-year enter these nursery areas in early spring (March and April) and remain there until fall when water temperatures drop.

Then these yearlings move into the deeper channel areas and down to the lower Bay and coastal areas. In most winters these age I + fish migrate out in the ocean but in warmer winters some may remain in deep water in lower Chesapeake Bay (Musick, personal communication). However, the Virginia Institute of Marine Science juvenile finfish survey for 1995 shows juvenile (as well as some adult) flounder occurring throughout most of the main stem of Chesapeake Bay and the major Virginia tributaries (Rappahannock, York, and James Rivers) over most of the year (Geer and Austin 1996; Figure 25; see also Wagner and Austin 1999).

Lower numbers occurred from December-March (Figure 26).

Wyanski (1990) found recruitment to occur from November to April on both sides of Virginia's Eastern Shore and from February to April on the western side of Chesapeake Bay.

Peak recruitment occurred in November-December on the Eastern Shore, compared to March-April on the western side of the Bay. Wyanski (1990) and Norcross and Wyanski (1988) also found that young-of-the-year occur in a variety of habitats, including shallow, mud bottomed marsh creeks, shallow sand substrates (including seagrass beds), deep sand substrate, and deep fine-sand substrates.

Tagged summer flounder have been recaptured from inshore areas to the northeast of their release sites in subsequent summers, leading to the hypothesis that their major nursery areas are the inshore waters of Virginia and North Carolina, and as they grow older and larger, they would return inshore to areas farther north and east of these nursery grounds (Poole 1966; Murawski 1970; Lux and Nichy 1981). However, tagging studies by Desfosse (1995) indicate that it is not the older and larger fish, but rather the smaller fish (length at tagging) which return to inshore areas north of Virginia. Summer flounder that were recaptured north of their release site in subsequent years were smaller (length at tagging) than those recaptured at their release sites, or to the south, in later years.

Desfosse (1995) suggests that while Virginia waters do indeed form part of the nursery grounds for fish which move north in subsequent years, they are primarily a nursery area for fish which will return to these same waters as they grow older and larger.

The estuarine waters of North Carolina, particularly those west and northwest of Cape Hatteras (Monaghan 1996) and in high salinity bays and tidal creeks of Core Sound (Noble and Monroe 1991), provide substantial habitat and serve as significant nursery areas for juvenile Mid-Atlantic Bight summer flounder. Powell and Schwartz (1977) found that juvenile summer flounder were most abundant in the relatively high salinities of the eastern and central parts of Pamlico Sound, all of Croatan Sound (Figure 13), and around inlets. Young-of-the-year disappeared from the catch during late summer, suggesting that the fish are leaving the estuaries at that time (Powell and Schwartz 1977). Upon leaving the estuaries, the juveniles enter the north-south, inshore-offshore migration of Mid-Atlantic Bight summer flounder (Monaghan 1996). Although North Carolina also provides habitat for summer flounder from the South Atlantic Bight, these fish do not exhibit the same inshore-offshore and north-south migration patterns as do Mid-Atlantic Bight fish (Monaghan 1996).

Summer flounder > 30 cm are rarely found in the estuaries of North Carolina, although larger fish are found around inlets and along coastal beaches. Powell and Schwartz (1977) also noted that juvenile summer flounder were most abundant in areas with a predominantly sandy or sand/shell substrate, or where there was a transition from fine sand to silt and clay.

Surveys by Hoffman (1991) in marsh creeks in Charleston Harbor, South Carolina showed that ricently settled summer flounder were abundant over a wide variety of substrates including mud, sand, shell hash, and oyster bars.

Page 8 HABITAT CHARACTERISTICS Dissolved Oxygen No information is available.

EGGS Temperature Smith (1973) found that eggs were most abundant in the water column where bottom temperatures were between 12 and 19"C; however, eggs were found in temperatures as cold as 9"C and as warm as 23°C.

The Northeast Fisheries Science Center (NEFSC) Marine Resources Monitoring, Assessment, and Prediction (MARMAP) ichthyoplankton data from 1978-1987 also shows that the eggs occur at water column temperatures around I I -230 C with peak abundances in the fall at temperatures of around 14-17"C (Figure 27). A temperature increase of 20TC above an acclimation temperature of about 15'C caused no mortality in early embryo stage eggs, but an increase of 16'C for 16 minutes or an increase of I 8'C for 2 minutes caused mortality in late embryo stage eggs (Itzkowitz et al. 1983).

The rate of development is dependent on temperature, with development rate increasing as temperature increases. Embryos held at 16"C developed slower than those at 21"C (Johns and Howell 1980). The incubation period from fertilization to hatching was estimated by Smith (1973) and Smith and Fahay (1970) to vary with temperature as follows: about 142 hours0.00164 days <br />0.0394 hours <br />2.347884e-4 weeks <br />5.4031e-5 months <br /> at 9'C; 72-75 hours at 18"C; and 56 hours6.481481e-4 days <br />0.0156 hours <br />9.259259e-5 weeks <br />2.1308e-5 months <br /> at 23'C.

Other incubation times under experimental conditions were 48-72 hours at 16-21"C and 216 hours0.0025 days <br />0.06 hours <br />3.571429e-4 weeks <br />8.2188e-5 months <br /> at 5TC (Johns and Howell 1980; Johns et al. 1981). In another study, summer flounder eggs required 72-96 hours to hatch while incubated at temperatures ranging from 15-18"C (Smigielski 1975).

Eggs from Narragansett Bay and Long Island Sound broodstocks incubated at 12.5'C started hatching 85 hours9.837963e-4 days <br />0.0236 hours <br />1.405423e-4 weeks <br />3.23425e-5 months <br /> after fertilization, while those incubated at 21 TC hatched 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> after fertilization (Bisbal and Bengtson 1995c).

Watanabe et al. (1999) studied the combined effects of temperature and salinity on eggs from captive summer flounder broodstock in the laboratory, and also showed that higher temperatures and salinities accelerated the rate of embryonic development through hatching. At 16TC and 20'C, the hatching rate was moderate to high at all experimental salinities (22, 27, and 33 ppt). At a higher temperature of 24 T, hatching rate was high at 33 ppt, but at lower salinities of 22 and 27 ppt, embryonic development and hatching was impaired, indicating a high-temperature-low-salinity inhibition.

Salinity The studies of Watanabe et al. (1998, 1999; see also previous section) suggest that whereas temperature produces marked differences in developmental rates and median hatching time of summer flounder embryos, the effects of salinity on median hatching time are relatively small.

Light Watanabe et al. (1998) studied the effects of light on eggs from captive summer flounder broodstock in the laboratory. Although the rate of embryonic development appeared to be faster at higher light intensities, hatching rate was not influenced by light intensity within the range of 0-2,000 Ix.

Water Currents No information is available.

Predation No information is available.

LARVAE/JUVENILES Temperature Larvae have been found in temperatures ranging from 0-23°C, but are most abundant between 9 and 18'C. NEFSC MARMAP ichthyoplankton data from 1977-1987 shows a seasonal shift in offshore larval occurrence with water column temperatures (Figure 28): most larvae are caught at temperatures > 12'C in the fall, from 4-10'C in the winter and from 9-14'C in the spring. Sissenwine et al. (1979) found prerecruit summer flounder in the Mid-Atlantic Bight are often most abundant at temperatures in excess of 15'C during the spring, summer and fall, and usually at depths of 40-60 m.

Larval flounder have been collected inshore earlier in years with mild winters than in years with severe winters (Cain and Dean 1976; Bozeman and Dean 1980). In the estuaries, transforming larvae (11-17 mm TL) have been collected over a temperature range from -2.0-14'C in Great Bay/Little Egg Harbor in New Jersey (Szedlmayer et al.

1992; Able and Kaiser 1994); from 2.1-17.6°C in the lower Chesapeake and Eastern Shore, Virginia (Wyanski 1990);

from 2-22°C in North Carolina (Williams and Deubler 1968b); and from 8.4-23.4"C in South Carolina (McGovern and Wenner 1990). Hettler et al. (1997) also reported an increase in summer larval abundance with increasing temperatures (7-18'C) in Beaufort Inlet, North Carolina; however,, they suggest that unknown factors are probably more important in causing peaks in the abundances of immigrating larvae (see also Hettler and Hare 1998).

Johns and Howell (1980) and Johns et al. (1981)

Page 9 performed experiments on yolk utilization and growth to yolk-sac absorption in summer flounder embryos and larvae.

Notochord lengths at hatching were 2.83-3.16 mm SL, with yolk-sac absorption completed at about 3.6 mm SL. For embryos and larvae reared at 21 TC, total yolk-sac absorption was complete by 120 h post-fertilization, at 16'C, complete absorption did not occur until 168-182 h, while at I I1C absorption did not occur until 287 h post-fertilization; these development times are similar to those reported by Watanabe et al. (1998) for larvae at 19TC. After hatching, total yolk-absorption at 21 C was complete in67 h, at 16TC it took 105 h, and at I 11C it took 137 h. Larvae reared in cyclic temperature regimes exhibited development rates intermediate to those at temperature extremes of the cycle.

All larvae reared at 5TC and in the 5-1 ITC cycle regime died prior to total yolk-sac absorption. Although incubation temperature had a significant effect on the larval length at hatching, there were no significant differences in the notochord length or yolk utilization efficiency of the larvae at the time of yolk-sac absorption. The similarity in growth and yolk utilization efficiency for larvae reared under these temperature regimes suggests that the physiological mechanisms involved are able to compensate for temperature changes encountered in nature. Larvae are able to acclimate to new temperatures in less than one day (Clements and Hoss 1977).

Watanabe et al. (1 999), using larvae hatched from eggs obtained from captive broodstock in the laboratory, also showed that development of yolk-sac larvae through first feeding was accelerated by higher temperatures within the range of 16-24'C, consistent with what was previously reported by Johns and Howell (1980) and Johns et al.

(1981). In all three studies the rate of yolk disappearance (yolk utilization efficiency) was faster at higher temperatures.

Watanabe et al. (1999) showed that the average time from the first-feeding to when 97% of the yolk-sac was absorbed in unfed larvae ranged from 2.4 to 4.3 times longer at 16TC (18.3 h) than at 20'C (4.3 h) or 24'C (7.7 h). Thus, larvae in 16'C waters may have considerably more time to initiate exogenous feeding before yolk reserves are exhausted [see also the discussion of the Bisbal and Bengtson's (1995c) study, below].

However, contrary to the Johns and Howell (1980) and Johns et al. (1981) studies, lower temperatures in the Watanabe et al. (1999) study produced larger larvae at the first-feeding and 97% yolk-sac absorption stages. Watanabe et al. (1999) state that these dissimilar results are attributable to the modifying influence of salinity, which differed between these studies (see the Salinity section, below). In their study, Watanabe et al. (1999) noted a high-temperature-low-salinity inhibition on growth and yolk utilization efficiency, but at a salinity of 33 ppt, there were no temperature-related differences in yolk utilization efficiency.

Watanabe et al. (1999) suggest this may be consistent with what was observed in the Johns and Howell (1980) and Johns et al. (1981) studies, which used seawater of an unspecified salinity.

Further interactions of temperature and salinity in the Watanabe et al. (1999) study will be discussed in the Salinity section, below.

Bisbal and Bengtson (1995c) show the interdependence of temperature and food availability (i.e., delay of initial feeding) and their effects on survival and growth of summer flounder larvae hatched from Narragansett Bay and Long Island Sound broodstock. Their laboratory observations occurred from the time of hatching throughout the period of feeding on rotifers. The larvae withstood starvation for longer times at lower temperatures.

They possessed sufficient reserves to survive starvation for 11 to 12 days when temperatures were maintained close to the experimentally determined lower tolerance limit (12.5°C; Johns et al. 1981). At temperatures close to the highest thermal limit reported to occur in their environment (21 0C; Smith 1973), larvae only survived for 6 to 7 days. At either temperature, best survival occurred when the larvae began to feed at the time of mouth opening, thus survival is also significantly affected by the time at which they first have access to exogenous food. At 12.50 C, every treatment group was represented by a low number of survivors which did not grow significantly from the initial figures at mouth opening.

Growth of the larvae at 21 C was inversely proportional to the duration of early starvation; the size distribution of the survivors of the 21'C experiment showed an increase in mean size and weight when the initial feeding delay was shorter.

The prevailing temperature conditions influence the duration of metamorphosis of pelagic larvae, with increasing temperatures resulting in a shorter metamorphic period. For example, Keefe and Able (1993) found the time to completion of metamorphosis in wild-caught New Jersey flounder maintained in the laboratory was clearly temperature dependent. While laboratory-reared summer flounder averaged 24.5 days (range 20-32 days) to complete metamorphosis (stage F-to stage I) at ambient spring temperatures of around 16.60C, wild-caught flounder held in heated water (daily average 14.5'C) advanced metamorphosis over controls kept at ambient winter temperatures (daily average 6.6°C). Total time required to complete metamorphosis in the heated water averaged 46.5 days (range 31-62 days); ambient winter temperature treatments resulted in delayed metamorphosis such that partial metamorphosis (stage H-to stage I) required as much as 92.9 days (range 67-99 days). Burke (1991) found that settling behavior of fish raised at I 8-200C occurred 28 days after hatching, although some took as long as 70 days.

Keefe and Able (1993) also found that mortality during metamorphosis in the laboratory ranged from 17-83%

among treatment groups, and was significantly greater in flounder maintained at approximately 4'C relative to those maintained at ambient New Jersey estuarine temperatures of around 10.1 0C. They found no apparent effect of starvation on either mortality or time to completion of metamorphosis at cool water temperatures (< 10°C).

Szedlmayer et al.

(1992) examined the temperature-induced mortality of

Page 10 young-of-the-year, early postmetamorphic (11-15 mm TL) summer flounder collected in New Jersey estuaries from November to May over a temperature range of 0-13TC.

Survival of metamorphosing larvae in the laboratory

• decreased drastically relative to controls when temperatures dropped below 2'C.

In trial 1, temperatures dropped steadily from 15-I° C over a 14-day period. Relatively little mortality (2%) occurred up to day 12. However, on days 13 and 14, temperatures dropped below 2'C causing 58%

mortality.

Temperatures then increased and fluctuated around 5oC but did not drop below 3"C, and during this period, mortality was lower (14%), for a total ambient temperature mortality of 74%. Only 3% total mortality occurred due to rearing environment in the control group, heated to 15TC.

During trial 2, in which controls were absent and ambient temperatures did not drop below 2°C, overall mortalities were lower (31%

total) and these occurred sporadically.

Malloy and Targett (1991) conducted laboratory experiments on juvenile summer flounder (41-80 mm TL) collected from Delaware to determine low temperature tolerance (2-30 C) and to measure feeding rate, assimilation efficiency, growth rate and growth efficiency at various temperatures.

Above 3'C, all the juveniles survived.

Mortality was 42% after 16 days at 2-3'C, and was highest in fish < 50 mm TL (1 g). Mean specific growth rates were not significantly different between 2 and 10'C, and these rates were not significantly different from zero. Additional mortality probably resulted from low growth rates caused by sub-optimal temperatures (< 10"C).

Malloy and Targett (1994a) also demonstrate that mortality of juveniles depends more on the rate of temperature decline than on the final exposure temperature: increased rate of temperature decline leads to decreased survival (lower LT5 0's).

Their study showed that juveniles from Delaware had greater tolerances for low temperatures (1-4TC) than juveniles from North Carolina.'

Malloy and Targett (1994a) showed that under maximum-feeding conditions, juvenile summer flounder (18-80 mm TL) from both Delaware and North Carolina do not exhibit positive growth rates at temperatures < 7-9°C.

[They consider this a more precise estimate of maintenance temperature than that reported in their earlier study (Malloy and Targett 1991).] Similarly, Peters and Angelovic (1971) in their laboratory studies of North Carolina juveniles reported predicted growth rates of close to zero at 10C.

Growth rates of juvenile flounder at temperatures above 10C are similar in studies on Delaware fish by Malloy and Targett (1991) and on North Carolina fish by Peters and Angelovic (1971). Malloy and Targett (1991) showed that mean growth rate increased to 2.4% per day at 14TC and 3.8% per day at 18'C and Peters and Angelovic (1971) demonstrated that specific growth rates of North Carolina juveniles were 5% and 10% per day, at 15 and 20'C, respectively.

Both studies showed that feeding rates increased with temperature, ranging from 1.04% body weight per day at 2TC to 23-24% body weight per day at 18TC. Peters and Angelovic (1971) reported an increase in feeding and growth efficiency rates with increasing temperatures to an optimum; beyond that optimum increasing temperatures are detrimental.

The optimal temperature in their experiments was 21'C.

Mean assimilation efficiency' (60.1%)

was not affected by temperature in the Malloy and Targett (1991) study. Mean growth efficiency (K1 ) for Delaware juveniles was significantly lower at 6'C (-23.1%) than at 14 and 18°C (18.4 and 22.1% respectively) and was highly variable.

Malloy and Targett (1994a, b) conclude that North Carolina juveniles had higher maximum growth rates and gross growth efficiencies than Delaware juveniles at temperatures between 6 and 18TC. Growth efficiency accounted for most of these differences in growth rates, because there were no differences in feeding rate or assimilation efficiency. Newly settled juveniles likely remain at settlement sizes for up to 6 months until temperatures are conducive for positive growth (Able et al. 1990; Malloy and Targett 1991, 1994b).

Malloy and Targett (1994a) also reported that juveniles from North Carolina and Delaware can survive at least 14 d without food at the 10-16'C temperatures typically found after settlement. However, growth rates are dependent on feeding rate at all temperatures they examined. Growth rates under starvation conditions and maintenance rations do not change between 10-16'C; however, scope for growth increases with temperature. Scope for growth of the North Carolina juveniles was higher than that of the Delaware juveniles between 10-16TC. In another study, Malloy and Targett (1 994b) showed that juveniles (18-80 mm TL) from both Delaware and a North Carolina sandy marsh were severely growth limited (< 20% of maximum growth) in May and June when temperatures were 13-20TC. Malloy and Targett (1 994a, b) conclude that prey availability is very important to the growth and condition of early juveniles during the months immediately following settlement, and changes in prey abundance may explain the patterns in growth limitation.

Mortality resulting from acute exposure to low temperatures in Mid-Atlantic Bight estuaries probably occurs during a 2 to 4 week period each winter. Szedlmayer et al. (1992) hypothesized that year class strength may be affected by winter temperature in New Jersey estuaries, as has been suggested for juveniles by Malloy and Targett (1991) for the Mid-Atlantic Bight as a whole. Recruitment success may be lower in years with late winter cold periods (i.e., March vs. December) due to increased numbers of fish inshore at that time of the year being exposed to lethal low temperatures (Malloy and Targett 1991). Thus, the timing of ingress is critical. However, because Malloy and Targett (1991) found that there was 100% survival at temperatures above 3'C, juveniles are probably able to survive most winter water temperatures encountered throughout Mid-Atlantic Bight estuaries.

However, Malloy and Targett (1994a) state that the magnitude of the variability in low temperatures may also be more important to prerecruit mortality than the magnitude of the temperature itself. The

Page 11 low feeding rates observed at low temperatures in the laboratory and the apparent lack of a starvation effect on low-temperature tolerance suggest that food limitation during winter is less important than the magnitude and variability of temperature minima.

They conclude that although low temperatures may contribute to prerecruit mortality south of Cape Hatteras, they are probably more important in more northern nurseries because they persist longer there.

In New Jersey, the most probable factors affecting survival of metamorphic summer flounder are the prevailing environmental conditions, especially the timing of ingress relative to estuarine water temperatures and predation (Szedlmayer et al. 1992; Keefe and Able 1993; Witting and Able 1993).

Tracking studies by Szedlmayer and Able (1993) in Schooner Creek, near Great Bay and Little Egg Inlet, New Jersey, suggest that tidal movements of juveniles (210-254 mm TL) may be in response to a preferred range of environmental parameters. Although they were collected in a wide range of habitats during their first year (Szedlmayer et al. 1992), during the August to September study period, they were found within a narrow range of water temperature (mean 23.5"C) and also dissolved oxygen. Small changes in these parameters may force the fish to move.

Several studies indicate that juvenile summer flounder in Chesapeake Bay may succumb to infections of the hemoflagellate Trypanoplasma bullocki at low temperatures (Burreson and Zwerneir 1982, 1984; Sypek and Burreson 1983). Effective immune response to the parasite was not noted in natural infections below 10C (Sypek and Burreson 1983). Therefore, because T. bullocki causes mortality of juvenile summer flounder during winter, suggesting that this mortality is temperature dependent, and since no fish with symptoms of the disease have been observed south of Cape Hatteras, Burreson and Zwerner (1984) hypothesize that the presence of the symptoms of this disease in juvenile summer flounder can be used as a measure of mortality north of Cape Hatteras. In addition, increased antibody production in early spring eliminates the infection in the flounder and the recovered fish are immune for at least one year, even if challenged at temperatures as low as 9'C (Burreson and Frizzell 1986).

NEFSC groundfish data shows a seasonal shift in offshore juvenile summer flounder occurrence with bottom temperatures (Figure 29): most juveniles are caught over a range of temperatures from. 10-27°C in the fall, from 3-13'C in the winter, from 3-17'C in the spring, and from 10-27TC in the summer. Massachusetts inshore trawl survey data also shows a seasonal shift in juvenile occurrence with bottom temperature (Figure 30). In the spring, most juveniles occur at a range of temperatures from 9-14'C, while in the fall they occur at temperatures from 15-2 1"C.

Salinity Watanabe et al. (1998) studied the effects of salinity and light intensity on yolk-sac larvae hatched from captive summer flounder broodstock in the laboratory. Significant effects of both salinity and light intensity on larval size were evident at hatching: larvae hatched under 500 Ix and salinities of approximately 35 ppt showed maximum values, a trend observed at the first feeding stage. However, in a later study by Watanabe et al. (1999), salinity did not influence development and growth rates of yolk sac larvae through the first feeding stage. Watanabe et al. (1998) suggest that the differences among the two studies may be attributed to the lower salinity range (22-33 ppt) used in this later study.

Also in the Watanabe et al. (1999) study, a high temperature of 240C, although not greatly influencing larval survival at 33 ppt, markedly impaired survival at the 97%

yolk-sac absorption stage when salinities were at 22 and 27 ppt, indicating high-temperature-low-salinity inhibition.

Conversely, a low temperature of 16'C enhanced larval survival at these reduced salinities, indicating a low-temperature-low salinity synergistic effect. Watanabe et al.

(1999) therefore hypothesize that moderate to high survival under all salinities at 16'C reflects an adaptability of the yolk sac larvae to inshore movement during the pelagic larval phase, whereas simultaneous exposure to higher temperatures and reduced salinities may increase mortality and affect year-class strength.

Transforming larvae and juveniles are most often captured in the higher salinity portions of estuaries. In New Jersey, Festa (1974) captured larval summer flounder in salinities of 26.6-35.6 ppt, while in two marsh creeks, larvae occurred at salinities ranging from 20-33 ppt (Able and Kaiser 1994).

In the lower Chesapeake Bay, Virginia, young-of-the-year were common in creeks with salinities >

15 ppt and were most abundant at the highest salinities, but were absent in a small tributary of the Poropotank River with salinities 3-11 ppt (Able and Kaiser 1994). In North Carolina, Williams and Deubler (1968a) found postlarval summer flounder in waters ranging from 0.02-35 ppt, with optimal conditions at 18 ppt. In addition, postlarval summer flounder (10-18 mm SL) were captured most frequently at salinities exceeding 7.4 ppt in the Cape Fear River Estuary, North Carolina (Weinstein et al. 1980b). However, Turner and Johnson (1973) reported that summer flounder of all ages occurred in the Newport River, North Carolina, at salinities of 3-33 ppt. Data from 1987-1991 trawl surveys from Pamlico Sound show that almost all individuals were collected in the sound while few were found in the adjacent subestuaries with lower salinities such as the Pamlico and Neuse Rivers (Able and Kaiser 1994). M. Street (North Carolina Dept. of Nat. Res. and Commer. Dev., Morehead City, NC, personal communication) mentioned that summer flounder distribution in Pamlico Sound varied in response to salinity changes. In dry years the area of higher salinity

Page 12 greatly expands in Pamlico Sound, and nursery areas similarly expand.

In South Carolina, larvae have been collected at salinities from 0-24.7 ppt (McGovern and Wenner 1990). Recently settled individuals (< 50 cm TL) in the Charleston Harbor estuary occur at both very low and very high salinities from February to March (Figure 31).

However by May, individuals20-100 mm TL are found at higher salinities of > 10 ppt. This suggests that as the flounder disperse in this estuary, they may move up into nearly fresh water, but as they grow they concentrate in the higher salinities of the lower estuary (Wenner et al. 1990a; Hoffman 1991; Able and Kaiser 1994).

In an estuarine complex in Georgia, Dahlberg (1972) noted that adult and juvenile summer flounder were most abundant in the higher salinity zones.

Malloy and Targett (1991) found that salinities of 10-30 ppt had no significant effect on feeding, growth, or survival of juvenile summer flounder (41-80 mm TL) in Delaware.

However, there was a slight interaction of temperature and salinity on growth rate, suggesting that fish have higher growth rates at high salinities and at high temperatures. This agrees with other laboratory studies which show that larval and juvenile growth rate and growth efficiency are greatest at salinities > 10 ppt (Deubler and White 1962; Peters and Angelovic 1971; Watanabe et al.' 1998, 1999), although Malloy and Targett (1991) suggest that there appears to be no significant physiological advantage or greater capacity for growth in waters of higher salinities, except at high temperatures. In other laboratory experiments, however, summer flounder grew best at higher salinities and more moderate temperatures, typical of habitats close to the mouths of estuaries (Peters 197 I). This could explain why Powell and Schwartz (1977) captured juveniles in the central portions. and around inlets of North Carolina estuaries at intermediate to high salinities of 12-35 ppt. Burke (1991) and Burke et al. (1991) also found newly settled summer flounder concentrated on tidal flats in the middle reaches of a North Carolina estuary. In the spring, older juveniles moved to high salinity salt marsh habitats. Young-of-the-year in spring were also significantly correlated with salinity (around 22-23 ppt) in eelgrass (Zostera marina) beds in the shallow water (1.2 m), high salinity area near Hog Island in Pamlico Sound (Ross and Epperly 1985; it is unclear if this applies to the larger juveniles and adults caught in the study with sizes up to 320 mm). Walsh et al. (1999), sampling in the Newport River and Back Sound estuaries adjacent to Beaufort Inlet from April-October 1994, also found that during the spring, larger juveniles (e.g.; 57, 60, 78 mm mean SL) occurred in the high salinities of the lower estuary on sand flats and in channels and along marsh edges.

But Burke (199 1) and Burke et al. (1991) make it clear that the summer flounder's distribution is due to substrate preference and is not affected by salinity.

Malloy and Targett (1991) also suggest that reported distributions of juvenile summer flounder at salinities > 12 ppt are probably the result of substrate and prey availability. In addition, the data of Walsh et al. (1999) from the Newport River and Back Sound estuaries* suggest that temperature, salinity, turbidity, and substrate type are related to juvenile summer flounder distribution and area of settlement, though they were unable to separate the independent effect of these variables.

Dissolved Oxygen Klein-MacPhee (1979) measured oxygen consumption rhythms in juvenile summer flounder over a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period in a flow-through metabolic chamber. The flounder showed a standard metabolic rate cycle, as manifested by oxygen consumption, with maximum consumption occurring between the hours of 2300 and 0100, and a minimum between 1130 and 1300.

Oxygen consumption varied inversely with the size of the fish.

Mean oxygen consumption was 33.5 mg/kg body weight per hour for 120 g fish; 31.1 mg/kg body weight per hour for 165 g fish; and 22.9 mg/kg per hour for 250 g fish.

Comparisons of metabolic rate cycles with activity cycles showed that the pattern was the same (high activity, high oxygen consumption in -the dark) but the peaks of the two cycles did not always coincide, and there was less day to day variation in the oxygen consumption cycle.

As reported previously under the temperature section, tracking studies by Szedlmayer and Able (1993) in Schooner Creek, near Great Bay and Little Egg Inlet, New Jersey suggest that tidal movements of juveniles (210-254 mm TL) may be in response to a preferred range of environmental parameters. They were found within a narrow range of water temperature and dissolved oxygen (mean 6.4 ppm),

and small changes in these parameters may force the fish to move.

Postlarvae of the closely related southern flounder (Paralichthys lethostigma) responded negatively to water with dissolved oxygen concentrations < 3.7 ml/l (or 5.3 mg/1) (Deubler and Posner 1963). The southern flounders also showed no difference in sensitivity to oxygen depletion when subjected to temperatures of 6.1, 14.4 and 25.3TC.

Growth rates of young-of-the-year winter flounder (Pseudopleuronectes americanus) were significantly reduced for fish exposed to low (2.3 ppm) and diurnally fluctuating (2.5-6.5 ppm; avg. 5.1 ppm) levels of dissolved oxygen (Bejda et al. 1992).

Light As stated previously, Watanabe et al. (1998) studied the effects of light intensity and salinity on yolk-sac larvae hatched from captive summer flounder broodstock in the laboratory. Significant effects of both salinity and light intensity on larval size were evident at hatching: larvae hatched under 500 Ix and salinities of approximately 35 ppt showed maximum values, a trend observed at the first

Page 13 feeding stage. Shorter notochord lengths of larvae grown under a light intensity of 2,000 lx compared with 0-1,000 lx is presumably related to higher light-induced activity and energy metabolism.

500 Ix appears to be the optimal intensity for culture of eggs and yolk-sac larvae.

Hettler et al. (1997) found that larvae inside Beaufort Inlet, North Carolina were more abundant in catches made later in the night, suggesting that they disperse into the water column from the edges and bottom. Night-time sampling by Rountree and Able (1997) at the mouths of marsh creeks in Little Egg Harbor estuary, New Jersey, suggests that young-of-the-year (range 138-390 mm SL) summer flounder make extensive use of these shallow habitats during night-time hours.

White and Stickney (1973) found that late larval and early postlarval summer flounder reared in the laboratory feed well with a surface light intensity of 300-500 foot candles (1 foot candle = 10.76 meter candles).

Other laboratory studies by Keefe and Able (1994) in New Jersey suggest that metamorphic flounder exhibit a diel pattern in burying behavior with a higher incidence of burying occurring during the day, with swimming in the water column at night. Klein-MacPhee (1979) showed that, under 12 h light/12 h dark photoperiods, maximum activity by juveniles occurred in the dark and had a bimodal distribution. Peaks occurred at 1900 and 0400 h. Under constant dark regimes, peak activity occurred at 2000 and 0100 with a minor peak at 1200. The free running period was 26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br />. In natural light, major activity occurred at 0300 with minor peaks at'1200 and 1800 h. In constant light, activity was reduced and found to be acyclic. Activity patterns of laboratory juveniles were different from wild adults, the latter being light active. Laboratory studies by Lascara (1981) on juveniles and adults from lower Chesapeake Bay showed that peak feeding activity (search-pursuits/unit time) generally occurred.during daylight hours between 0800 and 1200.

Grover (1998) studied the incidence of feeding of oceanic larval summer flounder collected north and east of Hudson Canyon. The incidence of feeding was defined as the percentage of frequency of larvae with prey in their guts, in relation to the total number of specimens examined in a time block. Pelagic larvae began feeding near sunrise; the presence of prey in the guts reached its lowest point at 0400-0599, then dramatically increased at 0600-0759. At 0800-0959, the incidence of feeding was 100%, and throughout daylight remained high until 2000.

Full guts were not observed until 1200-1359. Maximum gut fullness was at 1200-1559 and 2000-2159. The only time block in which all larvae contained prey in their guts was at 0800-0959.

These observations confirm the visual nature of oceanic larval feeding. The incidence of feeding in estuarine larvae was significantly lower than oceanic larvae at 1800-1959 and 2000-2159.

Surveys in the lower Chesapeake Bay, Virginia (Orth and Heck 1980; see also Lascara 1981) and near Beaufort Inlet, North Carolina (Adams 1976a) show that during daylight hours, juveniles tend to occupy areas in the estuaries that have submerged aquatic vegetation.

Water Currents Smith (1973) found that larvae did not drift far-from spawning areas, and were taken near the eggs. Williams and Deubler (1968a) stated that larvae shorter than 7 mm SL depend on currents for dispersal; however, there are no data that describe relationships between recruitment to nursery areas and wind-driven (Ekman) transport or prevailing directions of water flow. Greater densities of young fish were found in or near inlets, and greater numbers were captured during periods of the full moon (Williams and Deubler 1968a). Young-of-the-year summer flounder have been found in high concentrations around the mouths of tidal creeks (Szedlmayer et al. 1992; Szedlmayer and Able 1993; Rountree and Able 1997). This could serve to maximize energy efficiency, as the creek mouths are often areas of reduced current speed.

Laboratory experiments by Keefe and Able (1994) in New Jersey indicated an increase in burying behavior by early metamorphic summer flounder on a flood tide.

Although this may represent a mechanism that allows the flounder to remain in favorable habitats, field studies by Burke et al. (1998) showed that during flood' tides in Beaufort Inlet, North Carolina, the highest densities of transforming larvae occurred at mid-depths within the water column, while during ebb tide, the highest densities were at the bottom. Their position in the water column was dependent on tidal stage, and there was a shift in their distribution and abundance which was associated with the shift in tidal stage. However, the increase in the numbers of flounders in the water column occurred around slack tide, and preceded the rise in salinity which followed the onset of flood tide (Burke et al. 1998).

Dispersal in areas having strong tidal currents may be accomplished by diel vertical migrations that result in tidal transport (Weinstein et al. 1980a; Burke 1991; Burke et al.

1991; Burke et al. 1998). The shift in vertical distribution with tidal stage observed by Burke et al. (1998) in Beaufort Inlet indicates that flounders in Onslow Bay enter the estuary by tidal stream transport. In the laboratory, Burke et al. (1998) discovered that wild-caught G-H stage larvae had a regular pattern of activity correlated with the tidal cycle, and peak activity was associated with the time of ebb tide.

Interestingly, laboratory-reared flounder had no clear pattern of activity. The observed tidal rhythm of activity of the wild-caught flounder, coupled with field observations that they appear to make the vertical shift into the water column during slack tide (see previous paragraph) when current velocities are low, suggests that there is a behavioral component to their tidal stream transport (Burke et. al.

1998). The high activity during ebb tide seen in the laboratory suggests that the most active behavioral component of tidal stream transport involves avoidance of

Page 14 advection by the ebbing tide rather than movement into the water column and transport by the flood tide (Burke et al.

1998). Burke et al. (1998) also hypothesize that a change in behavior necessary for development of a tidal rhythm occurs during the eye migration phase of metamorphosis. The lack of a tidal activity pattern seen in laboratory-reared flounder suggests that development of a tidal rhythm is dependent on exposure to physical variables that are correlated with the tide.

Tidal transport of young-of-year summer flounder has also been shown to occur in a New Jersey marsh creek (Szedlmayer and Able 1993). Fish moved up the creek on flood tides and down the creek with ebb tides. Rountree and Able (1992b) and Szedlmayer and Able (1993) hypothesize that tidal movements of summer flounder in marsh creeks are the result of both foraging behavior and behavioral homeostasis (e.g., behavioral thermoregulation). Stomach fullness of fish captured leaving the creeks on ebb tides was significantly greater than that of fish captured entering the creeks on flood tides, suggesting that summer flounder undergo tidal movements to take advantage of high concentrations of prey available in the creeks. Although the flounder were found in a wide range of temperatures, salinities and dissolved oxygen concentrations, they generally stayed within narrow limits of these parameters.

Thus, movements may be related to the avoidance of environmental extremes.

Substrate/Shelter Powell and Schwartz (1977) state that benthic substrate appears to influence juvenile summer flounder and southern flounder distributions in Pamlico Sound and adjacent estuaries, North Carolina. Summer flounder were dominant in sandy substrates or where there was a transition from fine sand to silt and clay, while southern flounder were dominant in muddy substrates. Turner and Johnson,(1973) also note juvenile summer flounder occur more frequently over sandy substrates than mud or silt bottoms in Pamlico Sound.

Burke (1991) and Burke et al. (1991) demonstrated in their North Carolina study that it is salinity which affects the distribution of southern flounder while the most important factor affecting the distribution of summer flounder is substrate type.

Their data indicated that the highest probability of encountering juvenile summer flounder occurred on mixed to sandy substrates.

Walsh et al. (1999), who collected juveniles only during the spring and summer in estuaries adjacent to Beaufort Inlet from April-October 1994, also noted the same species-specific preferences in the type of marsh edge habitat occupied. Juvenile southern flounder were more abundant in the low salinity upper estuary on muddier substrates, while summer flounder juveniles were more abundant at higher salinities and on sandier substrates.

However, regarding juvenile summer flounder abundances alone, they found no significant differences across the various habitat types within the estuaries. Indeed, during both seasons, but particularly in the spring, higher abundances of recently recruited juveniles were found along marsh edges in mud substrate. Lower numbers were found on sand flats and channels in the lower estuary. There was, however, evidence of size-specific habitat segregation during the spring, with the larger juveniles (e.g.; 57, 60, 78 mm mean SL) occurring in those sand flats and channels in the lower estuary. As stated above, although the data of Walsh'et al. (1999) suggest substrate type, along with temperature, salinity, and turbidity are related to juvenile distribution and area of settlement, they were unable to separate the independent effect of these variables.

Juveniles make extensive use of marsh creeks (Wyanski 1990;.Burke et al. 1991; Malloy and Targett 1991; Rountree and Able 1992b, 1997; Szedlmayer et al. 1992; Szedlmayer and Able 1993) as well as other estuarine habitats. For example, as stated previously, surveys by Hoffman (1991) in marsh creeks in Charleston Harbor, South Carolina also showed that recently settled summer flounder were abundant over a wide variety of substrates including mud, sand, shell hash, and oyster bars. In Virginia, Wyanski (1990) and Norcross -and Wyanski (1988) found. newly recruited juvenile summer flounder in shallow, mud bottomed marsh creek habitat until they were 60-80 mm TL in late spring, at which time they were on shallow sand substrates (including seagrass beds), deep sand substrate, and deep fine-sand substrates. Although Keefe and Able (1994) found that metamorphic and juvenile summer flounder collected from Great Bay-Little Egg Harbor estuary in southern New Jersey showed a preference for sandy substrates in the laboratory, studies by Szedlmayer et al. (1992) and Rountree and Able (1992a, 1997) show that in southern New Jersey they also occur abundantly in marsh creeks with soft mud bottoms and shell hash.

Substrate preferences of metamorphic and juvenile summer flounder, as well as burying behavior, may be correlated to the presence and types of predators and prey (Keefe and Able 1994). For example, in North Carolina estuaries, Burke (1991) suggests the preferred habitat of summer flounder appears to be in the mid-estuary, which also appears to correspond to high densities of their principal prey. This in spite of the fact that Burke (1991) also demonstrated that metamorphosing larvae raised in the lab exhibit substrate preferences that correspond to the habitat of older flounders in the wild, preferring sand whether benthic prey species were present or excluded from test substrates. Timmons (1995) also reported a preference for sand by juvenile (7.6-24.9 cm TL) summer flounder from the south shores of Rehobeth and Indian River Bays, Delaware, but in addition the flounder were captured near large aggregations of the macroalgae Agardhiella tenera only when large numbers of their principal prey, the grass shrimp Palaemonetes vulgaris, were -present. Timmons (1995) suggests that the summer flounder are attracted to the algae because of the presence of the shrimp, but remain near the sand to avoid predation ("edge effect"). Indeed, in her

Page 15 laboratory experiments, the juvenile summer flounder did not show a preference for the macroalgae, and in caging experiments, blue crabs were least able to prey on the flounder in cages with sand bottoms only, but had an advantage in capturing the flounder in cages containing macroalgae.

Similar results have been reported in laboratory experiments by Lascara (1981) on larger juveniles and adults from lower Chesapeake Bay. Flounder appeared to utilize submerged aquatic vegetation (eelgrass) as a "blind", they lie-in-wait along the vegetative perimeter, effectively capturing prey (in this case, juvenile spot, Leiostomus xanthurus) which moved from within the grass.

In the absence of the eelgrass, the spot visually detected and avoided the flounder; the flounder therefore consumed fewer spot on average in the non-vegetated treatment than in the vegetated treatments. Therefore, Lascara (1981) concludes that the ambush tactics of summer flounder are especially effective when the flounder are in patchy habitats where they remain in the bare substrate (sand) between eelgrass patches.

Lascara (1981) also noted that if flounder remained within densely vegetated

areas, they would probably be conspicuous to prey. As the flounder moved through the vegetation in his laboratory experiments, the grass blades were matted down and essentially "traced out" their body shape. The flounder might also be conspicuous to potential predators as well,' again suggesting the "edge effect" hypothesis of Timmons (1995). Thus, flounder remain near the sand to both avoid predation and conceal themselves from prey.

Other studies have shown that summer flounder use vegetated habitats. Adams (I 976a) reported the occurrence of juvenile summer flounder in eelgrass meadows near Beaufort, North Carolina during the summer; YOY juveniles in spring also appeared to favor the eelgrass beds in the shallow water (1.2 m), high salinity (means 22-28 ppt) area near Hog Island in Pamlico Sound (Ross and Epperly 1985).

Paralichthys spp. in the eelgrass communities near Beaufort, North Carolina collectively accounted.for about 1% of the annual production and respiration of the fish assemblage (Thayer and Adams 1975; Adams 1976b). Hettler (1989) also reported juveniles in North Carolina salt marsh cordgrass habitat during flood tides. Orth and Heck (1980) and Heck and Thoman (1984) indicated that summer flounder used similar shallow vegetated areas during daylight in Chesapeake Bay; Lascara (1981) reports that juvenile and adult flounder entered and fed in these same areas. In a Virginia tidal marsh creek prior to late summer, juveniles were randomly distributed, but in late summer and early fall, they were more abundant in the adjacent seagrass beds (Weinstein and Brooks 1983). These data indicate that grass bed habitats are important to summer flounder, and any loss of these areas along the Atlantic seaboard may affect flounder stocks (Rogers and Van Den Avyle 1983).

In the inland bays of Delaware, Timmons (1995) suggests that macroalgal systems appear to act as ecological surrogates to seagrass beds and seagrass/macroalgal systems as described by various authors. As with seagrass systems' that attract juveniles when the submerged aquatic vegetation (SAV) increases from June to September, so does the macroalgae attract summer flounder, because, as stated previously, the macroalgae attracts their prey. This may also be true for Great Bay and Little Egg Harbor in southern New Jersey.

Szedlmayer and Able (1996) report that juvenile and adult summer flounder (140-416 mmn SL) were associated with the station considered to be a sea lettuce (Ulva lactuca) macroalgae habitat.

Conversely, also in Great Bay-Little Egg Harbor, Keefe and Able (1992) determined habitat quality as measured by relative growth of juvenile summer flounder (17-41 mm SL).

Growth did not appear to be related to the habitats tested, including eelgrass and adjacent unvegetated substrate, macroalgae (Ulva) and adjacent unvegetated substrate, and marsh creek. The fastest growth occurred in shallow bays and marsh creeks. However, Malloy and Targett (1994b) suggest that juvenile growth is related to substrate or habitat in the Newport River estuary, North Carolina because of the presence of specific prey items. The growth limitation of juveniles (18-80 mm TL) in one sandy-marsh habitat could be explained by the low abundance of mysids from May into summer, while the increasing abundance of other prey (polychaetes and amphipods) during that same month at a muddier site may account for favorable growth seen there.

Other diet studies in this estuary (Burke 1991, 1995; Burke et al. 1991) suggest that polychaetes are actually the preferred prey for juveniles of this size (see the Food Habits section below).

Food Habits The timing of peak spawning in October/November coincides with the breakdown of thermal stratification on the continental shelf and the maximum production of autumn plankton which is characteristic of temperate ocean waters of the northern hemisphere, thus assuring a high probability of adequate larval food supply (Morse 1981).

Initiation of feeding is a function of the rate and efficiency at which yolk-sac material is consumed, which in turn is dependent on incubation,temperature. As reported previously by Johns and Howell (1980) and Johns et al.

(1981), total yolk-absorption was complete in 67 h and 105 h at 21 `C and 16'C, respectively. Within those 3 to 4 days from hatching, summer flounder larvae complete the morphological differentiation of the digestive tract, jaw suspension, and accessory organs necessary for independent exogeneous feeding (Bisbal and Bengtson 1995b).

To repeat the results of the Bisbal and Bengtson (1995c) study:

they show the interdependence of temperature and food availability (i.e., delay of initial feeding) and their effects on survival and growth of summer flounder larvae hatched from Narragansett Bay and Long Island Sound broodstock. Their laboratory observations occurred from the time of hatching throughout the period of feeding on rotifers. The larvae withstood starvation for

Page 16 longer times at lower temperatures.

They possessed sufficient reserves to survive starvation for I 1 to 12 days when temperatures were maintained close to the experimentally determined lower tolerance limit (12.5 0C; Johns et al. 1981). At temperatures close to the highest thermal limit reported to occur in their environment (2 TC; Smith 1973), larvae only survived for 6 to 7 days. At either temperature, best survival occurred when the larvae began to feed at the time of mouth opening, thus survival is also significantly affected by the time at which they first have access to exogenous food. At 12.5°C, every treatment group was represented by a low number of survivors which did not grow significantly from the initial figures at mouth opening.

Growth of the larvae at 21 T was inversely proportional to the duration of early starvation; the size distribution of the survivors of the 210C experiment showed an increase in mean size and weight when the initial feeding delay was shorter.

Bisbal and Bengtson (1995a) also determined the nutritional status of lab raised larvae and juveniles from the same areas. Mortality due to starvation occurs later in the older ontogenetic states; i.e., 60 h in 6 day old larvae, 72 h in 16 day old larvae, 8 d in 33 day old larvae, and 10 d in 60 day old juveniles at a temperature of around 19'C.

In the laboratory, Peters 'and Angelovic (1971) reared postlarvae on a diet of zooplankton (mostly copepods) and Artemia nauplii;.Buckley and Dillmann (1982) also used Artemia for their larval feeding experiments. The larvae exhibited an exponential increase in daily ration with age and a linear increase with weight (Buckley and Dillmann 1982). Other investigators have raised larvae on rotifers (e.g., Bisbal and Bengtson 1995c).

Previous studies have inferred that larval and postlarval summer flounder initially feed on zooplankton and small crustaceans (Peters and Angelovic 1971; Powell 1974; Morse 1981; Timmons 1995). Grover (1998) studied the food habits of oceanic larval flounder collected north and east of Hudson Canyon. The diets of all stages of larvae were dominated by immature copepodites. The size of other prey was directly related to larval size. Preflexion larvae (1.9-6.9 mm SL) fed on, in order of importance: immature copepodites, copepod nauplii, and tintinnids, as well as bivalve larvae and copepod eggs. Flexion larvae (3.7-7.2 mm SL) fed on immature copepodites (mostly calanoids) -

and adult calanoid copepods. Premetamorphic (4.8-7.6 mm SL) and metamorphic (5.8-9.0 mm SL) larvae also fed on immature copepodites, but adult calanoid copepods (mostly Centropages typicus) and appendicularians were also prey items.

Studies on the food habits of late larval and juvenile estuarine summer flounder reveal that while they are opportunistic feeders and differences in diet are often related to the availability of prey, there also appears to be ontogenetic changes in diet. Smaller flounder (usually <

100 mm) seem to focus on crustaceans and polychaetes while fish become a little more important in the diets of the larger juveniles. In Great Bay-Little Egg Harbor estuary, New Jersey, Grover (1998) found that the primary prey of metamorphic (8.1-14.6 mm SL) summer flounder was the calanoid copepod Temora longicornis, indicating pelagic feeding. Evidence of benthic feeding was observed only in late-stage metamorphic flounder (H+ and I), where the prey included polychaete tentacles, harpacticoid copepods, and a mysid. Incidence of feeding, defined as the percentage of frequency of larvae with prey in their guts, in relation to the total number of specimens examined in a time block, declined as metamorphosis progressed, from 19.1% at stage G to 2.9% at stage I. Rountree and Able (1992b) also discovered that young-of-year summer flounder in Great Bay-Little Egg Harbor marsh creeks preyed on creek fauna in order of abundance (Rountree and Able 1992a): Atlantic silversides (Menidia menidia), mummichogs (Fundulus heteroclitus), grass shrimp (Palaemonetes vulgaris), and sand shrimp (Crangon septemspinosa) contributed most importantly to their diets. Seasonal shifts in diet reflected seasonal changes in creek faunal composition, and Rountree and Able (1992a) note that the maximum abundance of young-of-year summer flounder in August coincided with the peak in Atlantic silverside abundances. In Little Egg Harbor estuary, New Jersey, Festa (1979) reported that fish, including anchovies, sticklebacks and Atlantic silversides, comprised 32.6% of the diet volume of 6-24 cm summer flounder. The fishcomponent was supplemented by mysid and caridean shrimp, of which the sand shrimp Crangon septemspinosa was of somewhat more importance.

Timmons (1995) reported that juvenile (7.6-24.9 cm TL) summer flounder from Rehobeth Bay, Delaware; fed mostly on the shrimp Palaemonetes vulgaris as well as porturid and blue crabs. Flounder from Indian River Bay fed mostly on mysids.

Postlarvae (10.5-14.2 mm SL) in Chesapeake Bay have been found with guts full of the mysid Neomysis americana (Olney 1983). In Magothy Bay, Virginia, small summer flounder (4.2-19.8 cm) also fed mainly on Neomysis americana, but in addition, consumed larger proportions of amphipods, small fishes, small gastropod mollusks, and plant material than the larger fish (Kimmel 1973). Wyanski (1990) found that mysids were also the dominant prey of 100-200 mm TL summer flounder in the lower Chesapeake Bay and. Eastern Shore of Virginia. Lascara (1981) reported that larger juveniles and adults (avg. length 27.4 cm SL) from lower Chesapeake Bay fed on.juvenile spot (Leiostomus xanthurus), pipefish (Syngnathusfuscus), the mysid Neomysis americana, and shrimps (P. vulgaris, C.

septemspinosa).

Burke (1991, 1995) in his North Carolina field surveys in the Newport and North Rivers discovered that late larval and early juvenile summer flounder are active infaunal predators. Prey of summer flounder during the immigration period (11-22 mm SL) consisted of common estuarine crustaceans including harpactacoid copepods, polychaetes, and parts of infaunal animals such as polychaete tentacles (primarily from the dominant spionid Streblospio benedicti) gills and' clam siphons (Figure 32). The appendages of

Page 17 benthic animals appear to be the most 'important prey item for postlarval flounders.

The increasing importance of polychaetes and clam siphons was suggested with development, while feeding on harpactacoid copepods and amphipods was independent of stage. For juveniles 20-60 mm SL, polychaetes, primarily spionids (S. benedicti), were the most important part of the diet (Figure 32).

Burke (1991, 1995) suggests that the distribution of these dominant polychaetes may influence the distribution of summer flounder in this estuary and could explain the movement of juvenile summer flounder into marsh habitat [Burke et al.

1991; note the Malloy and Targett (1994b) study mentioned in the Substrate section, above]. Other prey items for this size class of summer flounder included invertebrate parts, primarily clam siphons; shrimp, consisting of the mysids Neomysis americana and palmonid shrimp; calanoid copepods, primarily Paracalanus; amphipods of the genus Gammarus; crabs, primarily Cqllinectes sapidus;'and fish.

Powell and Schwartz (1979) reported that larger juvenile (100-200 mm TL) summer flounder feed mainly on mysids (mostly Neomysis americana) and fishes throughout the year in Pamlico Sound, North Carolina (Figure 33). Mysids were found in relatively greater quantities in the smaller flounder, but as their size increased, the diet consisted of shrimps and fishes in similar quantities.

In South Carolina, Wenner et al. (1990a) reported that juveniles between 50-125 mm TL consumed only mysids and caridean shrimps (Palaemonetes sp., P. pugio, P.

vulgaris). The importance of fish (mostly bay anchovy, Anchoa mitchilli, and mummichogs) in the diet increased as summer flounder size increased.

In Georgia, Reichert and van der Veer (1991) found that juveniles from the Duplin River of around < 40 mm SL fed principally on harpacticoid copepods; they also report that Paralichthys species > 25 mm fed on increasing numbers of other crustaceans including mysids, crabs, Palaemonetes, as well as polychaetes. Summer flounder >

100 mm also fed on fish.

Co-occurring Species and Predation In Great Bay-Little Egg Harbor estuary in southern New Jersey, a survey by Witting et al. (1999) from 1989-1994 showed that the fall larval fish assemblage was more diverse than any of the other seasonal assemblages, with strong representation by summer flounder, Atlantic menhaden (Brevoortia tyrannus),

Atlantic croaker (Micropogonias undulatus), bay anchovy, and a few other species.

Larval and juvenile summer flounder undoubtedly are preyed upon until they grow large enough to fend for themselves. Results of food habit studies by NEFSC from 1969-1972 showed that Pleuronectiformes occurred in the stomachs of the following piscivores: spiny dogfish, goosefish, cod, silver hake, red hake, spotted hake, sea raven, longhorn sculpin, and fourspot flounder (Bowman et al. 1976). These data do not indicate the proportion of summer flounder among the flatfish prey taken, but it is likely that they are represented.

Following a thermal shock of 10°C above an acclimation temperature of 15'C, larvae were actually less susceptible to predation by striped killifish (Fundulus majalis) than control larvae (Deacutis 1978).

Witting and Able (1993), working in the laboratory with 11-16 mm TL transforming larvae from Great Bay-Little Egg Harbor, New Jersey, suggest that these small summer flounder are vulnerable to predation by a large size range of Crangon septemspinosa (around 10-50 mm TL) in New Jersey's estuaries. Laboratory experiments by Keefe and Able (1994) in New Jersey demonstrated that predation on metamorphic summer flounder influences burying behavior and perhaps substrate preference. The type and abundance of predators could determine whether a metamorphic summer flounder stays in the substrate or the water column.

For example, Keefe and Able's (1994) experiments showed that buried C. septemspinosa may reduce burying by the flounder, while pelagic mummichogs may cause more burying by the flounder during the day.

Timmons (1995) reports a preference for sand by juvenile (7.6-24.9 cm TL) summer flounder from the south shores of Rehobeth Bay and Indian River Bay, Delaware. In her study, the flounder were captured near large aggregations of the macroalgae Agardhiella tenera only when large numbers of their principal prey, the shrimp Palaemonetes vulgaris, were present. Timmons (1995) suggests that the summer flounder are attracted to the algae because of the presence of the shrimp, but the flounder remain near the sand to avoid predation ("edge effect").

Indeed, in her laboratory experiments, the juvenile summer flounder did not show a preference for the macroalgae, and in caging experiments, blue crabs were least able to prey on the flounder in cages with sand bottoms only, but had an advantage in capturing the flounder in cages containing macroalgae.

Laboratory studies by Lascara (1981) on flounder from lower Chesapeake Bay also suggest that in patchy seagrass/sand habitats, the flounder may avoid predation by staying in the sand near the seagrass beds, rather than in the grass beds themselves.

Lab studies in Georgia by Reichert and van der Veer (1991) on juveniles from the Duplin River found potential predators to be blue crabs (Callinectes spp.) and sea robins (Prionotus spp.).

ADULTS Temperature NEFSC groundfish data shows a seasonal shift in offshore adult summer flounder occurrence with bottom temperatures (Figure 34): most adults are caught over a range of temperatures from 9-260C in the fall, from 4-13 0C

Page 18 in the winter, from 2-20'C in the spring, and from 9-27'C in the summer. Massachusetts inshore trawl survey data also shows a seasonal shift in adult occurrence with bottom temperature (Figure 30). In the spring, most adults occur at a range of temperatures from 6-17"C, while in the fall they occur at temperatures from 14-21"C.

Prior to 1979, Sissenwine et al. (1979) reported that NEFSC trawl surveys on the continental shelf showed that the distribution of summer flounder by depth was related to their temperature distribution. During spring they were distributed widely over the continental shelf, from 0-360 m depth (compare with Figure 4), and primarily in waters between 8-16'C.

During summer the flounder were primarily captured in depths of less than 100 m, and in waters between 15-28TC.

The autumn distribution was also at depths of less than 100 m and temperatures between 12-28'C. During winter, they generally were found at depths greater than 70 m, and at temperatures between 5-I1 TC (Sissenwine et al. 1979).

Based on collections from the 1990-1996 Rhode Island Narragansett Bay survey, adults were distributed throughout the Bay and captured in all seasons except winter; in spring they were found in bottom temperatures above 6'C and below 15'C in autumn (Figure 35). By summer the adults occurred at nearly all temperatures and in autumn they were concentrated where temperatures exceeded 17'C.

In the Mid-Atlantic Bight north of Chesapeake Bay, spawning and the offshore limits of migration coincide with the inshore edge of the mass od cold bottom water that disappears along with the thermocline in November (Smith 1973).

A study by Stolen et al. (I 984a) compared the effect of temperature on the humoral antibody formation in the summer and winter flounder at 8, 12 and 17'C during the same time of the year. Summer flounder showed only a delay in the appearance of circulating antibody at lower temperatures while winter flounder showed both a delay and a marked suppression at lower temperatures.

Summer flounder produced a high titered antibody that persisted over a long period of time and over a wide temperature range, while in winter flounder antibody levels began decreasing after one month.

A similar, study on the kinetics of the primary immune response in summer flounder was also studied by Stolen et al. (1984b). The flounder produced antibody over a wide range of environmental temperatures ranging from 7.5-270 C.

At the lower environmental temperatures, a corresponding delay in the appearance of circulation antibody occurred, although the magnitude and duration of the response was not appreciably affected. After immunizing at 12"C, lowering the environmental temperature gradually to 8"C did not appear to inhibit an ongoing primary response. Typical secondary responses were seen in fishes kept at warmer temperatures, but when the temperature was lowered to 8'C, no anamnestic response was seen. Individual variation was most noticeable at middle temperature ranges.

Salinity Adult summer flounder return inshore to coastal waters in April through June, and are often found in the high salinity portions of estuaries [e.g., Abbe (1967) in Delaware, Tagatz and Dudley (1961) and Powell and Schwartz (1977) in North Carolina; Dahlberg (1972) in Georgia]. However, the adult summer flounder's distribution may be due more to substrate preference than salinity preference.

Dissolved Oxygen Effects of dissolved oxygen concentration on summer flounder adults has not been investigated (Rogers and Van Den Avyle 1983).

Festa (1977) reported that the high variability in catch rates of summer flounder off of New Jersey in the summer of 1976 appeared to be directly related to the movement of an anoxic water mass present that year.

Large numbers of summer flounder were forced into inlets and bays where they were more concentrated and vulnerable to the sport fishery (Freeman and Turner 1977).

Light Laboratory studies (Olla et al. 1972; Lascara 1981) and field collections (Orth and Heck 1980) indicate that adult summer flounder are active primarily during daylight hours.

To repeat.what was stated above for juveniles: laboratory studies by Lascara (1981) on juveniles and adults from lower Chesapeake Bay showed that peak feeding activity (search-pursuits/unit time) generally occurred during daylight hours between 0800 and 1200.

Water Currents No information is available.

Substrate/Shelter Adults have often been reported as preferring sandy habitats (Bigelow and Schroeder 1953; Schwartz 1964; Smith 1969).

For example, in Pamlico Sound, North Carolina, Powell and Schwartz (1977) found that summer flounder were most abundant at stations where quartz sand or coarse sand and shell predominated. In Barnegat Bay, New Jersey, Vouglitois (1983) suggests that both juvenile and adult summer flounder are found in greater numbers in the eastern portion of the Bay, where sandy sediments predominate. However, adults can camouflage themselves via pigment changes to reflect the substrate (Mast 1916).

Thus, they can be found in a variety of habitats with both mud and sand substrates, including marsh creeks, seagrass

Page 19 beds, and sand flats (Bigelow and Schroeder 1953; Dahlberg 1972; Orth and Heck 1980; Lascara 1981; Rountree and Able 1992a).

As previously explained above in the Section on juveniles, laboratory experiments by Lascara (1981) on larger juveniles and adults from lower Chesapeake Bay found that flounders appear to utilize eelgrass beds as

'blinds'; i.e., they lie-in-wait along the vegetative perimeter, effectively capturing prey which move from within the grass.

Lascara (1981) concludes that the ambush tactics of summer flounder are especially effective when the flounder are in patchy habitats where they remain in the bare substrate (sand) between eelgrass patches. Lascara (1981) also noted that if flounder remained within densely vegetated areas, they would probably be conspicuous to prey because, in his laboratory experiments, as the flounder moved through the vegetation, the grass blades were matted down and essentially "traced out" their body shape. The flounder might also be conspicuous to potential predators as well, suggesting the "edge effect" hypothesis of Timmons (1995).

Thus, the flounder remain near the sand to both avoid predation and conceal themselves from prey.

Food Habits Adult summer flounder are opportunistic feeders with fish and crustaceans making up a significant portion of their diet (Figure 36). Differences in diet between habitats or locations may be due to prey availability. The flounder are most active during daylight hours and may be found well up in the water column as well as on the bottom (Olla et al.

1972).

Included in their diet are: windowpane (Carlson 1991),

winter

flounder, northern

pipefish, Atlantic menhaden, bay anchovy, red hake, silver hake, scup, Atlantic silverside, American sand lance, bluefish, weakfish, mummichog, rock crabs, squids, shrimps, small bivalve and gastropod mollusks, small crustaceans, marine worms and sand dollars (Hildebrand and Schroeder 1928; Ginsburg 1952; Bigelow and Schroeder 1953; Poole 1964;,Smith and Daiber 1977; Allen et al., 1978; Langton and Bowman 1981; Curran and Able 1998).

In Little Egg Harbor estuary, New Jersey, Festa (1979) reports that at least seven species of fish occurred in the stomachs of 25-65 cm summer flounder. These included Atlantic silversides, anchovies, sticklebacks, silver perch, sea robins, winter flounder and pipefish.

Fish remains comprised 74.3% of.the diet volume. Brachyuran crabs, primarily Callinectes, were of secondary importance in the diet. In Hereford Inlet near Cape May, New Jersey, Allen et al. (1978) found that adult and juvenile summer flounder (200-400 mm) fed mostly on Crangon septemspinosa, mysids and fish.

Smith and Daiber (1977) reported that Delaware Bay adults < 45 cm TL fed on invertebrates, while those > 45 cm TL ate more fish. Food items found, in order of percent frequency of occurrence, included decapod shrimp (Crangon septemspinosa), weakfish (Cynoscion regalis),

mysids (Neomysis americana), anchovies (Anchoa sp.),

squids (Loligo sp.), Atlantic silversides (Menidia menidia),

herrings (Alosa sp.), hermit crabs (Pagurus longicarpus),

and isopods (Olencira praegustator).

In Magothy Bay, Virginia, large summer flounder (20.1-47.6 cm) fed mainly on Neomysis americana, as well as large crustaceans such as Squilla empusa, xanthid crabs, and squids.

The fish from this area are not mainly piscivorous, but the larger specimens (> 40.0 cm) did contain a higher percentage of fishes than did the smaller ones (Kimmel 1973). Lascara (1981) reports that larger juveniles and adults (avg. length 27.4 cm SL) from lower Chesapeake Bay fed on juvenile spot (Leiostomus xanthurus), pipefish (Syngnathus fuscus), the mysid Neomysis americana, and shrimps (P. vulgaris, C.

septemspinosa).

In South Carolina, Wenner et al. (1990a) showed that flounder 50-313 mm TL consumed mostly decapod crustaceans, especially caridean shrimps (Palaemonetes sp.,

P. pugio, P. vulgaris). The importance of fish (mostly bay anchovy, Anchoa mitchilli, and mummichogs) in the diet increased as summer flounder size increased.

Co-Occurring Species and Predation Spatial co-occurrence and dietary overlap among summer flounder, scup, and black sea bass have been previously documented (Musick and Mercer 1977; Gabriel 1989; Shepherd and Terceiro 1994).

For example, the composition and distribution of fish assemblages in the Middle Atlantic Bight was described by Colvocoresses and Musick (1979) by subjecting NEFSC bottom trawl survey data to the statistical technique of cluster analyses. Summer flounder, scup, northern sea robin, and black sea bass, all warm temperate species, were regularly classified in the same group during spring and fall. In the spring this group was distributed in the warmer waters on the southern shelf and along the shelf break at depths of approximately 152 m.

During the fall this group was distributed primarily on the inner shelf at depths of less than 61 m where they were often joined by smooth dogfish.

All of the natural predators of adult summer flounder are not fully documented, but larger predators such as large sharks, rays, and goosefish probably include summer flounder in their diets.

Laboratory studies by Lascara (1981) on flounder from lower Chesapeake Bay suggest that in patchy seagrass/sand habitats, the flounder may avoid predation by staying in the sand near the seagrass beds, rather than in the grass beds themselves.

Page 20 INSHORE SUMMER FLOUNDER HABITAT CHARACTERISTICS Habitat information is meaningful because habitat differences can be important in determining local abundances of summer flounder (Cadrin et al. 1995).

Because most of the summer flounder habitat research occurs inshore, Tables 2-4 present the inshore habitat parameters or requirements for summer flounder found in nearshore New Jersey, Delaware, and North Carolina, respectively.

Those States were chosen because of the amount of the high quality, habitat related research on summer flounder occurring there [by highest quality we mean Level 3 information as defined in the EFH Technical Manual (National Marine Fisheries Service, Office of Habitat Conservation 1998) and Interim Final Rule (Department of Commerce, National Oceanic and Atmospheric Administration 1997)]. Thus, we have also chosen to concentrate on studies (experimental or otherwise) which focus on the habitat parameter preferences, and are from published, peer-reviewed literature sources, rather than on information that merely attempts to correlate environmental variables with fish densities, such as that which often appears in general fisheries surveys. We heed the advice of Hettler et al. (1997), who suggest caution when interpreting correlations of environmental variables with fish abundances.

For example, they reported an increase in summer flounder larval abundance with increasing temperatures in Beaufort Inlet, North Carolina.

This could be caused by winter spawning and the larvae arriving at the inlet after a two to three month cross-shelf transport time, resulting in a higher larval abundance corresponding with rising temperatures.

Their statistical analyses suggest that unknown factors are probably more important in causing peaks in the abundances of immigrating larvae (see also Hettler and Hare 1998).

Table 5 is a summation and synthesis of Tables 2-4, and should provide an overall, yet more succinct view of current habitat requirements information on inshore summer flounder. The habitat parameter headings for all the tables are based upon those used in the Habitat Characteristics section, above.

STATUS OF THE STOCKS The following section is based on Terceiro (1995) and the Northeast Fisheries Science Center (1997).

The coverage is from New England to Cape Hatteras.

The stock is at a medium level of historical (1968-1996) abundance and is over-exploited. The age structure of the spawning stock has begun to expand, with 34% of the biomass at ages 2 and older in 1996, although under equilibrium conditions about 85% of the spawning stock biomass would be expected to be ages 2 and older. The 1995 year class is about average (1982-1996), but the 1996 year class is estimated to be the smallest since the poor year class of 1988.

Commercial landings of summer flounder averaged 13,200 mt during 1980-1988, reaching a high of 17,100 mt in 1984 (Figure 37). The recreational fishery for summer flounder harvests a significant proportion of the total catch, and in some years recreational landings have exceeded the commercial landings.

Recreational landings have historically constituted about 40% of the total landings.

Recreational landings averaged 9,800 mt during 1980-1988, and peaked in 1983 at 12,700 mt. During the late 1980s and into 1990, landings declined dramatically, reaching 4,200 mt in the commercial fishery in 1990 and 1,400 mt in the recreational fishery in 1989 (Table 6).

Reported 1996 landings in the commercial fishery used in the assessment were 5,770 mt and estimated 1996 landings in the recreational fishery were 4,704 mt (Table 6).

Spawning stock biomass declined 72% from 1983 to 1989 (18,900 mt to 5,200 mt), but has since increased with improved recruitment to 17,400 mt in 1996 (Figure 37; Table 6). The age structure of the stock is improving, with 34% of the spawning biomass in 1996 composed of fish of ages 2 and older, compared to only 17% in 1992.

Figure 38 shows the contrast between the distribution of summer flounder from periods of high abundances in the past (1974-1978) to recent periods of low abundances (1989-1993), for both adults and juveniles in the fall and spring.

RESEARCH NEEDS Obviously, there are many gaps in our understanding of the autecology of summer flounder. Because it is such a highly migratory species and occurs everywhere throughout its range, knowledge of its life history and habitat requirements can vary regionally, and what affects them in one area can easily cause repercussions in the population in another area. Even though summer flounder is managed and assessed as one stock throughout the U.S. EEZ, the question of multiple stocks, particularly in the Mid-Atlantic Bight, still needs to be settled from a scientific standpoint. There is a lack of knowledge concerning the habitat requirements for all life history stages, especially the offshore eggs and larvae, but even for the adults within our own estuaries, since much of the current habitat research has focused on estuarine larvae and juveniles (note Tables 2-5). Of course, more habitat information is needed on the inshore transforming larval and early juvenile stages, especially because their health affects the future growth and survival of the population. Finally, critical habitat preferences must be defined. For example, while it is likely that temperature may drive the seasonal movements of juveniles and adults in and out of the estuaries, it may have less effect on their choice of specific habitats within those estuaries, where substrate, salinity, etc. may be the overriding factors.

Once their habitat preferences are defined, their critical habitats can be more thoroughly delineated and mapped.

Page 21 ACKNOWLEDGMENTS This paper was originally presented as a rewrite of the habitat section of the summer flounder FMP with amendments [Mid-Atlantic Fishery Management Council (MAFMC) 1987, 1991].

The authors wish to thank Mark Terceiro, Anne Studholme, and Jeff Cross for reviews and editorial assistance, and Rande Ramsey-Cross, Judy Berrien, Claire Steimle, and Ferdinand Triolo for library assistance. Mark Terceiro provided the status of the stocks report. Rodney Rountree provided the original food habits data from the NEFSC trawl surveys with which Joe Vitaliano generated the pie charts. Frank Almeida provided much NMFS data and associated methodology and assisted with the figure captions.

REFERENCES CITED Abbe, G.R. 1967. An evaluation of the distribution of fish populations of the Delaware River estuary. M.S. thesis, Univ. Delaware, Newark, DE. 64 p.

Able, K.W. and S.C. Kaiser. 1994. Synthesis of summer flounder habitat parameters. NOAA Coastal Ocean Prog., Decision Analysis Ser. 1. NOAA Coastal Ocean Office, Silver Spring, MD. 68 p.

Able, K.W., R.E. Matheson, W.W. Morse, M.P. Fahay, and G. Shepherd.

1990. Patterns of summer flounder Paralichthys dentatus early life history in the Mid-Atlantic Bight and New Jersey estuaries. Fish. Bull.

(U.S.) 88: 1-12.

Adams, S.M. 1976a. The ecology of eelgrass, Zostera marina (L.), fish communities. I. Structural analysis. J.

Exp. Mar. Biol. Ecol. 22: 269-291.

Adams, S.M. 1976b. The ecology of eelgrass, Zostera marina (L.), fish communities. II. Functional analysis.

J. Exp. Mar. Biol. Ecol. 22: 293-311.

Allen, D.M., J.P. Clymer, III, and S.S. Herman. 1978. Fishes of the Hereford Inlet estuary, southern New Jersey.

Lehigh Univ., Dep. Biol. and Cent. Mar. Environ. Stud.

and The Wetlands Inst. 138 p.

Almeida, F.P:, R.E. Castaneda, R. Jesien, R.E. Greenfield, and J.M.

Burnett.

1992.

Proceedings of the NEFC/ASMFC summer

flounder, Paralichthys dentatus, aging workshop, I 1-13 June 1990, Northeast Fisheries Center, Woods Hole, Mass. NOAA Tech.

Mem. NMFS-F/NEC-89.7 p.

Anderson, W.W. and J.W. Qehringer. 1965. Biological-statistical census of the species entering fisheries in the Cape Canaveral Area. U.S. Fish Wild]. Serv. Spec. Sci.

Rep. Fish. 514. 79 p.

Bearden, C.M. and C.H. Farmer, III.

1972. Fishery resources of Port Royal Sound estuary. In M.

Thompson ed. Port Royal Sound environmental study.

p.

204-212.

South Carolina Water Resources Commission.

Bejda, A.J., B.A: Phelan, and A.L. Studholme. 1992. The effect of dissolved oxygen on the growth of young-of-the-year winter

flounder, Pseudopleuronectes americanus. Environ. Biol. Fishes 34: 321-327.

Berg, D.L. and J.S. Levinton. 1985. The biology of the Hudson-Raritan estuary, with emphasis on fishes.

NOAA Tech. Mem. NOS OMA 16. 170 p.

Berrien, P. and J. Sibunka. 1999. Distribution patterns of fish eggs in the United States northeast continental shelf ecosystem, 1977-1987. NOAA Tech. Rep. NMFS 145.

310 p.

Bigelow H.B. and W.C. Schroeder. 1953. Fishes of the Gulf of Maine. U.S. Fish Wildl. Serv. Fish. Bull. 53: 577 p.

Bisbal, G.A. and D.A. Bengtson. 1995a. Description of the starving condition in summer flounder, Paralichthys dentatus, early life history stages. Fish. Bull. (U.S.) 93:

217-230.

Bisbal, G.A. and D.A. Bengtson. 1995b. Development of the digestive tract in larval summer flounder. J. Fish Biol.

47: 277-291.

Bisbal, G.A. and D.A. Bengtson. 1995c. Effects of delayed feeding on survival and growth of summer flounder Paralichthys dentatus larvae. Mar. Ecol. Prog. Ser.

121: 301-306.

Bowman, R.E., R.O. Maurer, Jr., and J.A. Murphy. 1976.

Stomach contents of twenty-nine fish species from five regions in the northwest Atlantic - Data report. U.S.

NatI. Mar. Fish. Serv. Northeast Fish. Cent. Woods Hole Lab. Ref. Doc. No. 76-10. 37 p.

Bozeman, E.L., Jr. and J.M. Dean. 1980. The abundance of estuarine larval and juvenile fish in a South Carolina intertidal creek. Estuaries 3: 89-97.

Briggs, J.C. 1958. A list of Florida fishes and their distribution. Bull. Fla. State Mus. Biol. Sci. 2: 223-318.

Buckley, L.J. and D.W. Dillmann. 1982. Nitrogen utilization by larval summer flounder, Paralichthys dentatus (Linnaeus). J. Exp. Mar. Biol. Ecol. 59: 243-256.

Burke, J.S. 1991. Influence of abiotic factors and feeding on habitat selection of summer and southern flounder during colonization of nursery grounds. Ph.D.

dissertation, North Carolina State Univ., Raleigh, NC.

97 p.

Burke, J.S. 1995. Role of feeding and prey distribution of summer and southern flounder in selection of estuarine nursery habitats. J. Fish Biol. 47: 355-366.

Burke, J.S., J.M. Miller, and D.E. Hoss. 1991. Immigration and settlement pattern of Paralichthys dentatus and P.

lethostigma in an estuarine nursery ground, North Carolina, U.S.A. Neth. J. Sea Res. 27: 393-405.

Burke, J.S., M. Ueno, Y. Tanaka, H. Walsh, T. Maeda, I.

Kinoshita, T. Seikai, D.E. Hoss, and M. Tanaka. 1998.

The influence of environmental factors on early life history patterns of flounder. J. Sea Res. 40: 19-32.

Bums, R.W. 1974. Species abundance and diversity of larval fishes in a high-marsh tidal creek. M.S. thesis, Univ. South Carolina, Columbia, SC. 63 p.

Burreson, E.M. and L.J. Frizzell. 1986. The seasonal anti-

Page 22 body response in juvenile summer flounder (Paralichthys dentatus) to" the hemoflagellate Try-panoplasma bullocki. Vet. Immunol. Immunopathol.

12: 395-402.

Burreson, E.M. andD.E. Zwerner. 1982. The role of host biology, vector biology, and temperature in the distribution of Trypanoplasma bullocki inifections in the lower Chesapeake Bay. J. Parasitol. 68: 306-313.

Burreson, E.M. and D.E. Zwerner. 1984. Juvenile summer flounder, Paralichthys dentatus mortalities in the western Atlantic Ocean caused by the hemoflagellate Trypanoplasma bullocki, evidence from field and experimental studies. Helgol. Meeresunters. 37: 343-352.

Byrne, C.J. and T.R. Azarovitz. 1982. Summer flounder. In M.D. Grosslein and T.R.

Azarovitz eds.

Fish distribution. p.' 109-11 3. MESA New York Bight Atlas Monograph 15. N.Y. Sea Grant Institute, Albany, NY.

Cadrin, S.X., A.B. Howe, S.J. Correia and T.P. Currier.

1995. Evaluating the effects of two coastal mobile gear fishing closures on finfish abundance off Cape Cod.

Trans. Am. Fish. Soc. 15: 300-315.

Cain, R.E. and J.M. Dean. '1976. Annual occurrence, abundance and diversity of fish in a South Carolina intertidal creek. Mar. Biol. 36: 369-379.

Carlson, J.K. 1991. Trophic relationships among demersal fishes off New Haven harbor (New Haven, CT) with special emphasis on the winter flounder (Pseudo-pleuronectes americanus). M.S. thesis, South. Conn.

State Univ., New Haven, CT. 71 p.

Clements, L.C. and D.E. Hoss. 1977. Effects of acclimation time on larval* flounder (Paralichthys sp.) oxygen consumption. Assoc. Southeast. Biol. Bull. 24: 43.

Colvocoresses, JA. and J.A. Musick. 1979. Section 11:

NMFS ground fish survey. In Historical community structure analysis of finfishes. p. 45-78. Virginia Inst.

Mar. Sci. Spec. Rep. Applied Mar. Sci. Ocean Eng. No 198.

Curran, M.C. and K.W. Able. 1998. The value of tethering fishes (winter flounder and tautog) as a tool for' assessing predation rates. Mar. Ecol. Prog. Ser. 163:

45-51.

Cushing,. D.H.

1981.

Fisheries biology. A study in population dynamics. 2nd. ed. Univ. of Wisconsin Press, Madison, WI. 295 p.

Dahlberg, R.M. 1972. An ecological study of Georgia coastal fishes. Fish. Bull. (U.S.) 70: 323-353.

Deacutis, C.F. 1978. Effect of thermal shock on predator avoidance by larvae of two fish species. Trans. Am.

Fish. Soc. 107: 632-635.

Delaney, G.R. 1986. Morphometric and meristic stock identification of summer flounder (Paralichthys dentatus). M.S. thesis, Coll. William and Mary, Williamsburg, VA. 47 p.

Department of Commerce, National Oceanic and Atmospheric Administration. 1997. Interim final rule; request for comments. Federal Register, Vol. 62, No.

244, Dec. 19, 1997,.Rules and Regulations. 50 CFR Part 600, RIN 0648-AJ30: 66531-66559.

Desfosse, J.C. 1995. Movements and ecology of summer flounder, Paralichthys dentatus, tagged in the southern Mid-Atlantic Bight. Ph.D. dissertation, Coll. William and Mary, Williamsburg, VA. 187 p.

Desfosse, J.C., J.A. Musick, and A.D. Estes. 1988. Stock identification of summer flounder (Paralichthys dentatus) in the southern Mid-Atlantic Bight. Virginia Mar. Res. Comm. WB-86-01-02.35 p.

Deubler, E.E., Jr. 1958. A comparativestudy of postlarvae of three flounders (Paralichthys) in North Carolina.

Copeia 1958(2): 112-116.

Deubler, E.E., Jr. and G.S. Posner. 1963. Response of postlarval flounders, Paralichthys lethostigma, to water of low oxygen concentrations. Copeia 1963(2): 312-31T7 Deubler, E.E., Jr. and J.C. White. 1962. The influence of salinity on growth of post-larvae of the summer flounder Paralichthys dentatus. C6peia 1962(2): 468-469.

Dovel, W.L. 1981. Ichthyoplankton of the lower Hudson estuary, New York. N.Y. Fish Game J. 28: 21-39.

Festa, P.J. 1974. A study of the distribution of young and larvalsummer flounder in New Jersey estuarine waters.

New Jersey Dep. Environ. Prot., Misc. Rep. I IM.

Trenton, NJ. 30 p.

Festa, P.J. 1977. Observations on the summer flounder (Paralichthys dentatus) sport fishery in Great Bay, N.J.

during summer of 1976 in reference to anoxic water conditions. Appendix VII. In Oxygen depletion and associated environmental disturbances in the Middle Atlantic Bight in 1976. p. 463-471. U.S. Nat]. Mar.

Fish. Serv. Northeast Fish. Cent. Sandy Hook Lab.

Tech. Ser. Rep. 3.

Festa, P.J. 1979. The fish forage base of the Little Egg Harbor estuary. N.J. Dep. Environ. Prot., Div. Fish.,

Game and Shellfish., Bur. Fish. Nacote Creek Res.

Stat., Tech. Rep. 24M. 271 p.

Fogarty,.M.J. 1981. Review and assessment of the summer flounder (Paralichthys dentatus) fishery in the northwest Atlantic. U.S. Natl. Mar. Fish. Serv.

Northeast Fish. Cent. Woods Hole Lab Ref. Doc. No.

81-25.54 p.

Fogarty, M.J., G. Delaney, J.W. Gillikin, J.C. Poole, D.E.

Ralph, P.G. Scarlett, R.W. Smith, and S.J. Wilk. 1983.

Stock discrimination of summer flounder (Paralichthys dentatus) in the Middle and South Atlantic Bight:

results of a workshop. NOAA Tech. Mem. NMFS-F/NEC-18. 14 p.

Freeman, B.L. and S.C. Turner. 1977. The effects of anoxic water on the flounder (Paralichthys dentatus), a bottom dwelling fish. Appendix VI. In Oxygen depletion and associated environmental disturbances in the Middle Atlantic Bight in 1976. p. 451-462. U.S. Natl. Mar.

Fish. Serv. Northeast Fish. Cent. Sandy Hook Lab.

Tech. Ser. Rep. 3.

Page 23 Gabriel, W.L. 1989. Persistence in northwestern demersal fish assemblages. Northwest At. Fish. Organ. (NAFO)

Sci. Counc. Res. Doc. 89/77. 17 p.

Gaertner, M.P. 1976. Seasonal migration of fishes of importance to New York State. M.S. thesis, State Univ.

N.Y. Stony Brook, NY. 58 p.

Geer, P.J. and H.A. Austin. 1996. Juvenile finfish and blue crab stock assessment program bottom trawl survey annual data summary report, volume 1995. Spec. Sci.

Rep. 124, Vol.

1995. Virginia Inst. Mar. Sci.,

Gloucester Point, VA. 298 p.

Gilbert, C.R. 1986. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (south Florida): southern, gulf, and summer flounders. U.S. Fish Wildl. Serv. Biol. Rep. 82 (11.54). 24 p.

Ginsburg, I. 1952. Flounders of the genus Paralichthys and related genera in American waters. U.S. Fish Wildl.

Serv. Fish. Bull. 52: 267-35 1.

Goode, G.B. 1884. The fisheries and fishery industries of the United States.Section I. Natural history of useful aquatic animals. Govt. Print. Office. Washington, DC.

Plates.

Gottschall, K, M.W. Johnson, and D.G. Simpson. In review.

The distribution and size composition of finfish, American lobster, and long-finned squid in Long Island Sound, based on the Connecticut Fisheries Division bottom trawl survey, 1984-1994. NOAA Tech. Rep.

Grimes, B.H., M.T. Huish, J.H. Kerby, and D. Moran. 1989.

Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (Mid-Atlantic): summer and winter flounder. U.S. Fish Wildl.

Serv. Biol. Rep. 82 (11.112). 18 p.

Grosslein, M.D. and T.R. Azarovitz. 1982. Fish distribution.

MESA New York Bight Atlas Monograph 15, N.Y. Sea Grant Inst., Albany, N.Y. 182 p.

Grover, J.J. 1998. Feeding habits of pelagic summer flounder, (Paralichthys dentatus), larvae in oceanic and estuarine habitats. Fish. Bull. (U.S.) 96: 248-257.

Gutherz, E.J. 1967. Field guide to the flatfishes of the family Bothidae in the western North Atlantic. U.S. Fish Wildl. Serv. Circ. 263. 47 p.

Hamer, P.E. and F.E. Lux. 1962. Marking experiments on fluke (Paralichthys dentatus) in 1961. Minutes 21st Ann. Meet., Append. MA6, Atlantic States Marine Fisheries Commission. Washington, DC. 6 p.

Heck, K.L. and T.A. Thoman. 1984. The nursery role of seagrass meadows in the upper and lower reaches of the Chesapeake Bay. Estuaries 7: 70-92.

Herman, S.S. 1963. Planktonic fish eggs and larvae of Narragansett Bay. Limnol. Oceanogr. 8: 103-109.

Hettler, W.F., Jr. 1989. Nekton use of regularly-flooded saltmarsh cordgrass habitat in North Carolina, USA.

Mar. Ecol. Prog. Ser. 56: 111-118.

Hettler, W.F., Jr. and D.L. Barker. 1993. Distribution and abundance of larval fishes at two North Carolina inlets.

Estuar. Coast. Shelf Sci. 37: 161-179.

Hettler, W.F., Jr. and J.A. Hare. 1998. Abundance and size of larval fishes outside the entrance to Beaufort Inlet, North Carolina. Estuaries 21: 476-499.

Hettler, W.F., Jr., D.S. Peters, D.R. Colby, and E.H. Laban.

1997. Daily variability in abundance of larval fishes inside Beaufort Inlet. Fish. Bull. (U.S.) 95: 477-493.

Hicks, B.

1972.

Seasonal distribution and relative abundance of fishes in the channel reaches and shore areas. In M. Thompson ed. Port Royal Sound environmental study. p. 193-195. South Carolina Water Resources Commission.

Hildebrand, S.F. and L.E. Cable. 1930. Development and life history of fourteen teleostean fishes at Beaufort, N.C. Bull. U.S. Bur. Fish. 46: 383-488.

Hildebrand, S.F. and W.C. Schroeder. 1928. Fishes of Chesapeake Bay. Bull. U.S. Bur. Fish. 43(1): 366 p.

Hoffman, W.G., II. 1991. Temporal and spatial distribution of ichthyofauna inhabiting the shallow marsh habitat of the Charleston Harbor estuary. M.S. thesis, Coll. of Charleston, SC. 137 p.

Holland, B.F.

1991, Summary of summer flounder (Paralichthys dentatus) tagging data from the Atlantic Ocean offshore North Carolina and Virginia. North Carolina Div. Mar. Fish. Morehead City, NC.

Howe, A.B., T.P. Currier, S.J. Correia, and J.R. King. 1997.

Resource assessments. Massachusetts Div. Mar. Fish.

Proj. Rep. F-56-R (Seg 2). 10 p.

Ichthyological Associates, Inc. 1980. An ecological study of the Delaware River near Artificial Island, 1968-1976:

a summary. Prepared for Public Service Electric and Gas Co. by Ichthyological Associates, Inc., Ithaca, NY.

303 p.

Itzkowitz, N., J.R. Schubel, and P.M.J. Woodhead. 1983.

Responses of summer flounder, Paralichthys dentatus, embryos to thermal shock. Environ. Biol. Fishes 8: 125-135.-

Johns, D.M. and W.H. Howell. 1980. Yolk utilization in summer flounder (Paralichthys dentatus) embryos and

.larvae reared at two temperatures. Mar. Ecol. Prog. Ser.

2: 1-8.

Johns, D.M., W.H. Howell, and G. Klein-MacPhee. 1981.

Yolk utilization and growth to yolk-sac absorption in summer flounder (Paralichthys dentatus) larvae at constant and cyclic temperatures. Mar. Biol. 63: 301-308.

Jones, W.J. and J.M. Quattro. 1999. Genetic structure of summer flounder (Paralichthys dentatus) populations north and south of Cape Hatteras. Mar. Biol. 133: 129-135.

Keefe, M. and K.W. Able. 1992. Habitat quality in New Jersey estuaries:

habitat-specific growth rates of juvenile summer flounder in vegetated habitats. Final Rep. for the New Jersey Dep. Environ. Prot. Energy.

Trenton, NJ. 26 p..

Keefe, M. and K.W. Able. 1993. Patterns of metamorphosis in summer flounder, Paralichthys dentatus. J. Fish Biol.

42: 713-728.

Page 24 Keefe, M. and K.W. Able. 1994. Contributions of biotic factors to settlement in summer flounder, Paralichthys dentatus. Copeia 1994(2): 458-465.

Keller, A.A., G. Klein-MacPhee, and J.S.O. Bums. 1999.

Abundance and distribution of ichthyoplankton in Narragansett Bay, Rhode Island, 1989-1990. Estuaries 22: 149-163.

Kimmel, J.J.

1973. Food and feeding of fishes from Magothy Bay, Virginia. M.S. thesis, Old Dominion Univ., Norfolk, VA. 190 p.

Klein-MacPhee, G. 1979. Growth, activity and metabolism studies of summer flounder Paralichthys dentatus (L.)

under laboratory conditions. Ph.D. dissertation, Univ.

Rhode Island, Kingston, RI. 99 p.

Langton, R.W. and R.E. Bowman. 1981. Food of eight northwest Atlantic pleuronectiform fishes. NOAA Tech.

Rep. NMFS SSRF-749. 16 p.

Lascara, J. 1981. Fish predator-prey interactions in areas of eelgrass (Zostera marina). M.S. thesis, Coll. William and Mary, Williamsburg, VA. 81 p.

Leim, A.H. and W.B. Scott. 1966. Fishes of the Atlantic coast of Canada. Bull. Fish. Res. Board Can. 155. 485 p.

Lucy, J.A. and C.G. Barr. 1994. Experimental monitoring of Virginia artificial reefs using fisherman's catch data.

Bull. Mar. Sci. 55: 524-537.

Lux, F.E. and F.E. Nichy. 1981. Movements of tagged summer flounder, Paralichthys dentatus, off southern New.England. NOAA Tech. Rep. NMFS SSRF-752. 16 p.

[MAFMC] Mid-Atlantic Fishery Management Council.

1987. Fishery Management Plan for the summer flounder fishery. October 1987. MAFMC. [Dover, DE.]

157 p. + appendices.

[MAFMC] Mid-Atlantic Fishery Management Council.

1991. Amendment 2 to the Fishery Management Plan for the summer flounder fishery. Vol. 1. May 1991.

MAFMC. [Dover, DE.] 164 p. + appendices.

Malloy, K.D. and T.E. Targett. 1991. Feeding, growth and survival of juvenile summer flounder Paralichthys dentatus: experimental analysis of the effects of temperature and salinity. Mar. Ecol. Prog. Ser. 72: 213-223.

Malloy, K.D. and T.E. Targett. 1994a. Effects of ration limitation and low temperature on growth, biochemical condition, and survival of juvenile summer flounder from two Atlantic coast nurseries. Trans. Am. Fish.

Soc. 123: 182-193.

Malloy, K.D. and T.E. Targett.

1994b. The use of RNA:DNA ratios to predict growth limitation of juvenile summer flounder (Paralichthys dentatus) from Delaware and North Carolina estuaries. Mar. Biol. 118:

367-375.

Mast, S.O. 1916. Changes in shade, color and pattern in fishes and their bearing on the problems of adaptation and behavior with special reference to the flounders Paralichthys and Ancylopsettra. Bull. U.S. Bur. Fish.

34: 173-238.

McGovern, J.C. and C.A. Wenner.

1990. Seasonal recruitment of larval and juvenile fishes into impounded and non-impounded marshes. Wetlands 10: 203-222.

Merriman, D and R.C. Sclar. 1952. The pelagic fish eggs and larvae of Block Island Sound. In G.A. Riley et al.

eds. Hydrographic and biological studies of Block Island Sound. p. 165-219. Bull. Bingham Oceanogr.

Collect. 13.

Michels, S.F. 1997. Coastal finfish assessment survey, April 1, 1996 - March 31, 1997. Ann. Rep., Delaware Div.

Fish. Wildl., Project F-42-R-8.

Miller, G.L. and S.C. Jorgenson. 1969. Seasonal abundance and length frequency distributions of some marine fishes in coastal Georgia. U.S. Fish Wildl. Serv. Data Rep. 35. Washington, DC. 102 p.

Monaghan, J.P., Jr. 1992. Migration and. population dynamics of summer flounder (Paralichthys dentatus) in North Carolina. Study 3A. Completion Rep. Proj. F-

29. North Carolina Dep. Environ., Health, and Nat.

Res., Div. Mar. Fish. Morehead City, NC. 36 p.

Monaghan, J.P., Jr. 1996. Life history aspects of selected marine recreational fishes in North Carolina. Study 2.

Migration of paralichthid flounders tagged in North Carolina. Completion Rep. Grant F-43. North Carolina Dep. Environ., Health, and Nat. Res., Div. Mar. Fish.

Morehead City, NC. 44 p.

Morse, W.W. 1981. Reproduction of the summer flounder, Paralichthys dentatus (L.). J. Fish Biol. 19: 189-203.

Murawski, W.S. 1970. Results of tagging experiments of summer flounder, Paralichthys dentatus, conducted in New Jersey waters from 1960-1967. New Jersey Div.

Fish, Game and Shellfish. Misc. Rep. No. 5M.

Lebanon, NJ. 72 p..

Murawski, W.S. and P.J. Festa. 1976. Ovary maturation in the summer flounder, Paralichthys dentatus. New Jersey Div. Fish, Game and Shellfish. Misc. Rep. No.

16M; Lebanon, NJ. 16 p.

Musick, J.A. and L.P. Mercer. 1977. Seasonal distribution of black sea bass, Centropristis striata, in the Mid-Atlantic Bight with comments on the ecology and fisheries of the species. Trans. Am. Fish. Soc. 106: 12-25.

National Marine Fisheries Service.

1997. Report to Congress. Status of fisheries of the United States:

Report on the status of fisheries of the United States.

September 1997. [Homepage of the National Marine Fisheries Service]. [Online]. Available: http://www.

nmfs.gov/sfa/Fstatus.html.

National Marine Fisheries Service, Office of Habitat Conservation. 1998. Technical guidance to NMFS for implementing the Essential Fish Habitat requirements for the Magnuson-Stevens, Act. Draft. January, 9, 1998.

Neville, W.C., C. Dickinson, and J. Westman. 1939.

Miscellaneous species. In A biological survey of the salt waters of Long Island. 1938. 28th Ann. Rep. N.Y.

State Cons. Dep., Suppl., Pt. 1: 107-152.

Page 25 Noble, E.B. and R.J. Monroe. 1991. Classification of Pamlico Sound nursery areas: recommendations for critical habitat criteria. North Carolina Dep. Environ.,

Health, and Nat. Res., Div. Mar. Fish. Proj. No. 89-09.

Morehead City, NC. 70 p.

Norcross, B.L. and D.M. Wyanski. 1988. Chesapeake Bay stock assessment committee III, project 40. (Mimeo). 8 p.

Northeast Fisheries ScienceCenter. 1997. Report of the 25th Northeast Regional Stock Assessment Workshop (25th SAW): Stock Assessment Review Committee (SARC) consensus summary of assessments. Northeast Fish. Sci.

Cent. Ref. Doc. 97-14. 143 p.

O'Brien, L., J. Burnett, and R.K. Mayo. 1993. Maturation of nineteen species of finfish off the northeast coast of the United States, 1985-1990. NOAA Tech. Rep. NMFS 113. 66 p.

Olla, B.L., C.E. Samet, and A.L. Studholme. 1972. Activity and feeding behavior of the summer flounder (Paralichthys dentatus) under controlled laboratory conditions. Fish. Bull. (U.S.) 70: 1127-1136-.

Olney, J.E. 1983. Eggs and early larvae of the bay anchovy Anchoa mitchilli and the weakfish Cynoscion regalis, in lower Chesapeake Bay with notes on associated ichthyoplankton. Estuaries 6: 20-35.

Olney, J.E.

and G.W.

Boehlert.

1988.

Nearshore ichthyoplankton associated with seagrass beds in the lower Chesapeake Bay. Mar. Ecol. Prog. Ser. 45: 33-43.

Orth, R.J. and K.L. Heck, Jr. 1980. Structural components of eelgrass (Zostera marina) meadows in the lower Chesapeake Bay - fishes. Estuaries 3: 278-288.

Parker, R.O., Jr., R.B. Stone and C.C. Buchanan. 1979.

Artificial reefs off Murrells Inlet, South Carolina. Mar.

Fish. Rev. 41(9): 12-24.

Pearcy, W.G. and S.W. Richards. 1962. Distribution and ecology of fishes in the Mystic River, Connecticut.

Ecology 43: 248-259.

Peters, D.S. 1971. Growth and energy utilization of juvenile flounder, Paralichthys dentatus and Paralichthys lethostigma, as affected by temperature, salinity, and food availability. Ph.D. dissertation, North Carolina

.State Univ., Raleigh, NC. 69 p.

Peters, D.S. and J.W. Angelovic.

1971.

Effect of temperature, salinity, and food availability on growth and energy utilization of juvenile summer flounder, Paralichthys dentatus. In D.J. Nelson ed. Proc. 3rd Nat]. Symp. Radioecology USAEC Conf.,-71050 I-Pl.

p. 545-554. National Technical Information Service, Springfield, VA.

Poole, J.C. 1961. Age and growth of the fluke in Great South Bay and their significance to the sport fishery.

N.Y. Fish Game J. 8: 1-18.

Poole, J.C. 1962. The fluke population of Great South Bay in relation to the sport fishery. N.Y. Fish Game J. 9: 93-117.

Poole, J.C. 1964. Feeding habits of the summer flounder in Great South Bay. N.Y. Fish Game J. 11: 28-34.

Poole, J.C. 1966. A review of research concerning summer flounder and needs for further study. N.Y. Fish Game J. 13: 226-231.

Powell, A.B. 1974. Biology of the summer flounder, Paralichthys dentatus, in Pamlico Sound and adjacent waters, with comments on P. lethostigma and P.

albigutta. M.S. thesis, Univ. North Carolina, Chapel Hill, NC. 145 p.

Powell, A.B. 1982. Annulus formation on otoliths and growth of young summer flounder from Pamlico Sound, North Carolina. Trans. Am. Fish. Soc. 111: 688-693.

Powell, A.B.and R.E. Robbins. 1998. Ichthyoplankton adjacent to live-bottom habitats in Onslow Bay, North Carolina. NOAA Tech. Rep. NMFS 133. 32 p.

Powell, A.B. and F.J. Schwartz. 1977. Distribution of Paralichthid flounders (Bothidae: Paralichthys) in North Carolina estuaries. Chesapeake Sci. 18: 334-339.

Powell, A.B. and F.J.Schwartz. 1979. Food of Paralichthys dentatus and P. lethostigma (Pisces: Bothidae) in North Carolina estuaries. Estuaries 2: 276-279.

Reichert, M.J.M. and H.W. van der Veer. 1991. Settlement, abundance, growth and mortality of juvenile flatfish in a subtropical tidal estuary (Georgia, U.S.A.). Neth. J.

Sea Res. 27: 375-391.

Reid, R., F. Almeida, and C. Zetlin. 1999. Essential fish habitat source document: Fishery independent surveys, data sources, and methods. NOAA Tech. Mem. NMFS-NE-122. 39 p.

Rogers S.G. and M.J. Van Den Avyle. 1983. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (South Atlantic):

summer flounder. U.S. Fish Wildl. Serv. FWS/OBS-82/11.15. 14 p.

Ross, J.L., J.H. Hawkins, and D.A. DeVries. 1990.

Assessment of North Carolina winter trawl fishery September 1982 - April 1985. North Carolina Div. Mar.

Fish. Spec. Sci. Rep. No. 53. Morehead City, NC. 97 p.

Ross, S.W. and S.P. Epperly. 1985. Utilization of shallow estuarine nursery areas by fishes in Pamlico Sound and adjacent tributaries. In A. Ydfiez-Arancibia ed. Fish community ecology in estuaries and coastal lagoons:

towards an ecosystem integration, Chap. 10. p. 207-232. UNAM Press, Mexico.

Rountree, R.A. and K.W. Able. 1992a. Fauna of polyhaline marsh creeks in southern New Jersey: composition, abundance and biomass. Estuaries 15: 171-186.

Rountree, R.A. and K.W. Able. 1992b. Foraging habits, growth, and temporal patterns of salt-marsh creek habitat use by young-of-year summer flounder in New Jersey. Trans. Am. Fish. Soc. 121: 765-776.

Rountree, R.A. and K.W. Able. 1997. Nocturnal fish use of New Jersey marsh creek and adjacent bay shoal habitats. Estuar. Coast. Shelf Sci. 44: 703-711.

Schreiber, R.A. 1973. The fishes of Great South Bay. M.S.

thesis, State Univ. N.Y. Stony Brook, NY. 199 p.

Schwartz, F.J. 1961. Fishes of Chincoteague and Sinepuxent

Page 26 bays. Am. Midi. Nat. 65: 384-408.

Schwartz, F.J. 1964. Fishes of Isle of Wight and Assawoman bays near Ocean City, Maryland. Chesapeake Sci. 5:

172-193.

Schwartz, F.J., P. Perschbacher, M. McAdams, L. Davidson, K. Sandoy, C. Simpson, J. Duncan, and D. Mason.

1979a. An ecological study of fishes and invertebrate macrofauna utilizing the Cape Fear River estuary, Carolina Beach Inlet, and adjacent Atlantic Ocean. A summary report 1973-1977. Vol. 14. Inst. Mar. Sci.,

Univ. North Carolina, Morehead City, NC. 571 p.

Schwartz, F.J., P. Perschbacher, M. McAdams, L. Davidson, C. Simpson, K. Sandoy, J. Duncan, J. Tate, and D.

Mason. 1979b. An ecological study of fishes and invertebrate macrofauna utilizing the Cape Fear River estuary, Carolina Beach Inlet, and adjacent Atlantic Ocean. Annual report for 1978. Vol. 15. Inst. Mar. Sci.,

Univ. North Carolina, Morehead City, NC. 326 p.

Seagraves, R.J. 1981. Delaware marine fishing surveys.

Delaware Fish. Bull. 2: 7-9.

Shepherd, G.R. and M. Terceiro.

1994. The summer flounder, scup, and black sea bass fishery of the Middle Atlantic Bight and southern New England waters.

NOAA Tech. Rep. NMFS 122. 13 p.

Simpson, D.G., P.T. Howell, and M.W. Johnson. 1990a. A study of marine recreational fisheries in Connecticut, 1984-1988: Marine finfish survey. Job 6. p. 127-146.

Federal Aid to Sport Fish Restoration F54R, Final Rep.

March 1, 1984-February 29, 1988. Connecticut Dep.

Environ. Prot. Div. Mar. Fish. Old Lyme, CT.

Simpson, D.G., M.W. Johnson, and K. Gottschall. 1990b. A study of marine recreational fisheries in Connecticut:

Marine finfish survey. Job 2. p 10-47. Federal Aid to Sport Fish Restoration F54R, Annual Performance Rep.

March 1, 1989-February 28, 1990. Connecticut Dep.

Environ. Prot. Div. Mar. Fish. Old Lyme, CT.

Simpson, D.G., M.W. Johnson, and K. Gottschall. 1991. A study of marine recreational fisheries in Connecticut:

Marine finfish survey. Job 2. p 16-45. Federal Aid to Sport Fish Restoration F54R, Annual Performance Rep.

March 1, 1990-February 28, 1991. Connecticut Dep.

Environ. Prot. Div. Mar. Fish. Old Lyme, CT.

Sissenwine, M.P., R.R. Lewis, and R.K. Mayo. 1979. The spatial and seasonal distribution of summer flounder (Paralichthys dentatus) based on research vessel bottom trawl surveys. U.S. Nati. Mar. Fish. Serv.

Northeast Fish. Cent. Woods Hole Lab. Ref. Doc. 79-

55. 101 p.

Smigielski, A.S. 1975. Hormone induced spawnings of the summer flounder and rearing of the larvae in the laboratory. Prog. Fish-Cult. 37: 3-8.

Smith, R.W. 1969. An analysis of the summer flounder, Paralichthys dentatus (L.), population in the Delaware Bay. M.S. thesis, Univ. Delaware, Newark, DE. 72 p.

Smith, R.W. and F.C. Daiber. 1977. Biology of the summer flounder, Paralichthys dentatus, in Delaware Bay. Fish.

Bull. (U.S.) 75: 823-830.

Smith, R.W., L.M. Dery, P.G. Scarlett, and A. Jearld, Jr.

1981.

Proceedings of the summer flounder (Paralichthys dentatus) age and growth workshop; 20-21 May 1980; Northeast Fisheries Center, Woods Hole, MA. NOAA Tech. Mem. NMFS-F/NEC-11. 30 p.

Smith, W.G. 1973. The distribution of summer flounder, Paralichthys dentatus, eggs and larvae on the continental shelf between Cape Cod and Cape Lookout, 1965-66. Fish. Bull. (U.S.).71: 527-548.

Smith, W.G. and M.P. Fahay. 1970. Description of eggs and larvae of summer flounder, Paralichthys dentatus. U.S.

Fish Wildl. Serv. Res. Rep. 75. 21 p.

Stender, B.W. and R.M. Martore.

1990. Finfish and invertebrate communities. In R.F. Van Dolah, P.H.

Wendt, and E.L. Wenner eds. A physical and ecological characterization of the Charleston Harbor estuarine system. Chap. VIII, p. 241-288. Mar. Res. Div., South Carolina Wild]. Mar. Res. Dep., Final Rep. Charleston, SC.

Stolen, J.S., S. Draxler, and J.J. Nagle. 1984a. A comparison of temperature-mediated immunomodulation between two species of flounder. I mmunol. Comm. 13: 245-253.

Stolen, J.S., T. Gahn, V. Kasper, and J.J. Nagle. 1984b. The effect of environmental temperature on the immune response of a marine teleost (Paralichthys dentatus).

Dev. Comp. Immunol. 8: 89-98.

Sypek, J.P. and E.M. Burreson. 1983. Influence of temperature on the immune response of juvenile summer flounder Paralichthys dentatus and its role in the elimination of Trypanoplasma bullocki infections.

Dev. Comp. Immunol. 7: 277-286.

Szedlmayer, S.T. and K.W. Able. 1992. Validation studies of daily increment formation for larval and juvenile summer flounder, Paralichthys dentatus. Can. J. Fish.

Aquat. Sci. 49: 1856-1862.

Szedlmayer, S.T. and K.W. Able.

1993. Ultrasonic telemetry of age-0 summer flounder, Paralichthys dentatus, movements in a southern New Jersey estuary.

Copeia 1993(3): 728-736.

Szedlmayer, S.T. and K.W. Able. 1996. Patterns of seasonal availability and habitat use by fishes and decapod crustaceans in a southern New Jersey estuary. Estuaries 19: 697-709.

Szedlmayer, S.T., K.W. Able, and R.A. Rountree. 1992.

Growth and temperature-induced mortality of young-of-the-year summer flounder (Paralichthys dentatus) in southern New Jersey. Copeia 1992(1): 120-128.

Tagatz, M.E. and D.L. Dudley. 1961. Seasonal occurrence of marine fishes in four shore habitats near Beaufort, N.C., 1957-1960. U.S. Fish Wildl. Serv. Spec. Sci. Rep.

Fish. 390. 19 p.

Terceiro, M. 1995. Summer flounder. In Conservation and Utilization Division, Northeast Fisheries Science Center eds. Status of the fishery resources off the northeastern United States for 1994. p. 69-70. NOAA Tech. Mem.

NMFS-NE-108.

Thayer, G.W. and S.M. Adams. 1975. Structural and

Page 27 functional aspects of a recently established Zostera marina community. In L.E. Cronin ed. Estuarine research, Vol. 1. p. 518-540. Academic Press, NY.

Timmons, M. 1995. Relationships between macroalgae and juvenile fishes in the inland bays of Delaware. Ph.D.

dissertation, Univ. Delaware, Newark, DE. 155 p.

Turner, W.R. and G.N. Johnson. 1973. Distribution and relative abundance of fishes in Newport River, North Carolina. NOAA Tech. Rep. NMFS SSRF-666.23 p.

Van Housen, G. 1984. Electrophoretic stock identification of summer flounder, Paralichthys dentatus. M.S. thesis, Coll. William and Mary, Williamsburg, VA. 66 p.

Vouglitois, J.J. 1983. The ichthyofauna of Barnegat Bay, New Jersey -- relationships between long term temperature fluctuations and the population dynamics and life history of temperate estuarine fishes during a five year period, 1976-1980. M.S. thesis, Rutgers Univ., New Brunswick, NJ. 304 p.

Wagner, C.M. and H.M. Austin. 1999. Correspondence between environmental gradients and summer littoral fish assemblages in low salinity reaches of the Chesapeake Bay, USA. Mar. Ecol. Prog. Ser. 177: 197-212.

Walsh, H.J., D.S. Peters, and D.P. Cyrus. 1999. Habitat utilization by small flatfishes in a North Carolina estuary. Estuaries 22: 803-813.

Warlen, S.M. and J.S. Burke. 1990. Immigration of larvae of fall/winter spawning marine fishes into a North Carolina estuary. Estuaries 13: 453-461.

Watanabe, W.O., S.C. Ellis, E.P. Ellis, and M.W. Feeley.

1999. Temperature effects on eggs and yolk sac larvae of the summer flounder at different salinities. N. Am. J.

Aquaculture 61: 267-277.

Watanabe, W.O., M.W. Feeley, S.C. Ellis, and E.P. Ellis.

1998. Light intensity and salinity effects on eggs and yolk sac larvae of the summer flounder. Prog. Fish-Cult.

60: 9-19.

Weinstein, M.P. 1979. Shallow marsh habitats as primary nurseries for fishes and shellfishes, Cape Fear River, North Carolina. Fish. Bull. (U.S.) 77: 339-357.

Weinstein, M.P. and H.A. Brooks. 1983. Comparative ecology of nekton residing in a tidal creek and adjacent seagrass meadow:

community composition and structure. Mar. Ecol. Prog. Ser. 12: 15-27.

Weinstein, M.P., S.L. Weiss, R.G. Hodson, and L.R. Gerry.

1980a. Retention of three taxa of postlarval fishes in an intensively flushed tidal estuary, Cape Fear River, North Carolina. Fish. Bull. (U.S.) 78: 419-436.

Weinstein, M.P., S.L. Weiss, and M.F. Walters. 1980b.

Multiple determinants of community structure in shallow marsh habitats, Cape Fear River Estuary, North Carolina. USA. Mar. Biol. 58: 227-243.

Weisberg, S.B., P. Himchak, T. Baum, H.T. Wilson, and R.

Allen. 1996. Temporal trends in abundance of fish in the tidal Delaware River. Estuaries 19: 723-729.

Wenner, C.A., J. C. McGovern, R. Martore, H. R. Beatty, and W.A. Roumillat. 1986. Ichthyofauna. In M.R.

DeVoe and D.S. Baughman eds. South Carolina coastal wetland impoundments: ecological characterization, management, status and use. Vol. II: Technical synthesis. Chap. 14, p. 414-526. South Carolina Sea Grant Consortium, Tech. Rep. SC-SG-TR-86-2.

Charleston, SC.

Wenner, C.A., W.A. Roumillat, J.E. Moran, M.B. Maddox, L.B. Daniell, III, and J.W. Smith. 1990a. Investigations on the life history and population dynamics of marine recreational fishes in South Carolina. Part 1. South Carolina Wildl. Mar. Res. Dep.,'Mar. Res. Research Inst., Charleston, SC.

Wenner, E.L., J. Archambault, and J. Boylan. 1990b.

Recruitment of fishes and decapod crustaceans into nursery habitats. In R.F. Van Dolah, P.H. Wendt, and E.L. Wenner eds.

A physical and ecological characterization of the Charleston Harbor estuarine system. Chap. 9, p. 289-384. Mar. Res. Div., South Carolina Wildl. Mar. Res. Dep., Final Rep. Charleston, SC.

Wenner, E.L., W.P. Coon, III, M.H. Shealy, Jr., and P.A.

Sandifer. 1981. Species assemblages, distribution, and abundance of fishes and decapod crustaceans from the Winyah Bay estuarine system, S.C. Contrib. No. 137, South Carolina Mar. Res. Cent. Tech. Rep. No. 3, South Carolina Sea Grant Consort. Charleston, SC. 61 p.

Westman, J.R. and W.C. Neville. 1946. Some studies on the life history and economics of fluke (Paralichthys dentatus) of Long Island waters. An investigation sponsored jointly by the State of New York Conservation Dep., U.S. Dep. Interior, and Town of Islip, NY. 15 p.

White, D.B. and R.R. Stickney. 1973. A manual of flatfish rearing. Georgia Mar. Sci. Cent. Tech. Rep. Ser. 73-7.

Skidaway Island, GA. 36 p.

Wilk, S.J., D.G. McMillan, R.A. Pikanowski, E.M.

MacHaffie, A.L. Pacheco, and L.L. Stehlik. 1997. Fish, megainvertebrates, and associated hydrographic observations collected in Newark Bay, New Jersey, during May 1993-April 1994. U.S. Nati. Mar. Fish.

Serv. Northeast Fish. Sci. Cent. Ref. Doc. 97-10. 91 p.

Wilk, S.J., W.W. Morse, D.E. Ralph, and T.R. Azarovitz.

1977. Fishes and associated environmental data collected in New York Bight, June 1974-June 1975.

NOAA Tech. Rep. NMFS-SSRF-716.53 p.

Wilk, S.J., W.G. Smith, D.E. Ralph, and J. Sibunka. 1980.

Population structure of summer flounder between New York and Florida based on linear discriminant analysis.

Trans. Am. Fish. Soc. 109: 265-271.

Williams, A.B. and E.E. Deubler, Jr. 1968a. Studies on macroplanktonic crustaceans and ichthyoplankton of the Pamlico Sound complex. North Carolina Dep. Cons.

Dev., Spec. Sci. Rep. 13. 91 p.

Williams, A.B. and E.E. Deubler, Jr. 1968b. A ten year study of macroplankton in North Carolina estuaries:

Assessment of environmental factors and sampling

Page 28 success among bothid flounders and penaeid shrimps.

Chesapeake Sci. 9: 27-41.

Witting, D.A. and K.W. Able. 1993. Effects of body size on probability of predation for juvenile summer and winter flounder based on laboratory experiments. Fish. Bull.

(U.S.) 91: 577-581.

Witting, D.A., K.W. Able, and M.P. Fahay. 1999. Larval fishes of a Middle Atlantic Bight estuary: assemblage structure and temporal stability. Can. J. Fish. Aquat.

Sci. 56: 222-230.

Wyanski, D.M. 1990. Patterns of habitat utilization in age-O summer flounder (Paralichthys dentatus). M.S. thesis, Coll. William and Mary, Williamsburg, VA. 46 p.

Page 29 Table I. Presence of summer flounder inshore, by State, as documented by authors cited in the text and personal communications from each States' flounder experts.

Author

[Location Jan IFeb IMar Apr May Jun IJul

[Aug ISep Oct INov IDec Notes Howe personal communication Smith personal communication Poole 62 Szedlmayer et al. 92 MA shoals s. of Cape Cod

& Cape Cod Bay CT Long Island Sound NY Great South Bay, Long Island NJ Great Bay, Little Egg Harbor A

E IEEEEEEEEEEEEEE EEEEEEE A

A: peak

/

B tEH lit B I I It It ---

• 1

/

A EEEEEEE EE EEEEEEE Hereford Inlet, Allen etat.

78 near Cape May Murawski 70 Festa 74 Keefe and Able 93 Sandy Hook &

Cape May NJ estuaries; Sandy Hook to Great Bay NJ estuaries TL L/TL TL llllllflllilllI llltll11If l J

TL TL H11 HT1111111 A

J,A tIltIttlltIt 1

!EEEEEEE lllllmIIIlIII mean length 38cm TL: 11-17mm, J: YOY, 60-326mm TL: 12-15mm J/ A: 200-400m A: 230-700mm Il.L 5-21mm; enter est. early Oct-late Jan most yrs, as late as March TL: 10-15mm, most abundant Oct-Dec J: YOY, 160-320mm TL ULn IIIIIIIIIIIII

[llliulml]

Ilannllulll IIHHIIIIIIII llllllllllllll TL HHtlmHlIIIIllHHttmtH Able et al. 90 NJ estuaries J: peak IEEEEEEEIEEEEEEEIEEEEEEE EBEEEEEEIEEEEEEE i

presence L

larvae peak abundance TL transforming larvae limited numbers J

juveniles IIIIIIIIII peak ingress A

adults IflltItIl]

ingress EEEEEE egress

Page 30 Table I. cont'd.

Author Location Jan Feb Mar Apr May Jun Jul Auci Sep Oct Nov Dec Notes DE Smith personal Delaware Bay A

A: peak some communication

'adults present all year Smith and Delaware Bay J/A: peak Dailer 7

......some Daiber77 juveniles present in deep parts of bay every winte month VA Musick Eastern Shore & J In milder personal lower tttttttttttt

-ttttttttttt-

-EEEEEEE EEEEEEE winters communication Chesapeake Bay some age 1+ fish remain in bay Eastem Shore, A

seaside tttttttttttt EEEEEEE inlets/lagoons lower A

Chesapeake Ba tttttttt EEE EEE Wyanski 90 both sides of J

peak Eastern Shore Ill/llllIllllll llllll lllllllIIIIIIIIIII flllllll recruitment Nov-Dec western J

peak Chesapeake Ba tttttttttttttt I/I/11/1111/I IIIIII1111111 recruitment March-April presence L

larvae peak abundance TL transforming larvae limited numbers J

juveniles HIIIIIIIII peak ingress A

adults tttttttttttt ingress EEEEEE egress

Page 31 Table 1. cont'd.

Author Location Jan.

Feb Mar ADr May Jun Jul Aug Sep.

Oct' Nov Dec Notes NC Hettler and Oregon Inlet, TL TL: peak ingress Barker 93 TL Ocracoke Inlet IIIII11/111 J

J=YOY, present Powelland 20 mos. from Schwartz 77 Pamlico sound mid winter recruitment to -Au of 2nd yr.

Newport River, TL Burkeoet al. 91 North River HIIIIH I

TL = 11-17mm SL estuaries Monaghan personal Beaufort Inlet TL cofuiajoIIlllllllI TL: peak ingress communicatior

/

Tagatz and

.fTIJle"T/=180 Dudley 61 Beaufort tntet 11JJ=11-l80mm TL Weinstein 79 Cape Fear Rive TL = 9-16mm SL SC Wenneret al Charleston TIlJJ 90a Harbor & vicinitt TLJ = 10-20mm T presence L

larvae peak abundance TL transforming larvae limited numbers J

juveniles IIIIIIIIII peak ingress A

adults ttttttttttlt ingress EEEEEE egress

Page 32 Table 2. Habitat parameters for summer flounder, Paralichthys dentatus: inshore New Jersey.

Life Stage Authors Size Range Geographic Time Period Habitat Substrate Temperature Location TRANSFORMING Grover 1998 8.1-14.6 mm Great Bay, Little Fall, winter, Little Sheepshead LARVAE SL Egg Harbor spring 89-95 Creek (metamorphic)

Keefe and 10-15.6 mm Great Bay, Little Nov 90-Nov 91 Little Sheepshead Sand preference Increased temps. =

Able 1993, SL, mean 12.8 Egg Harbor.

Nov 90-Mar 91 Creek by both shorter metamorphic 1994 (metamorphic) metamorphs and period. Greater juveniles.

mortality at 4"C. No effect of starvation on mortality or time to completion of metamorphosis at temps. < 10"C.

Szedlmayer et 11-17 mm TL Great Bay, Little Nov 88-Apr 89 0-13'C, mortality al. 1992 (metamorphic)

Egg Harbor

< 2oC Witting and 11-16 mm TL Great Bay, Little Jan-Feb 90 9-12'C Able 1993 (metamorphic) Egg Harbor JUVENILES Rountree and mean 132 mm Great Bay, Little Apr-Nov 88 Schooner, New, mud mean 19'C Able 1992a SL (YOY),

Egg Harbor Apr-Oct 89 Foxboro creeks range ca.16-245 mm Rountree and mean 238 mm Great Bay, Little 1987-1990 Schooner, New, mud mean 22'C, range Able 1992b TL (YOY).

Egg Harbor Foxboro, Stoney 15-27"C range creeks 156-312 mm Rountree and mean 192 mm Little Egg Harbor May/July-Nov 90 Foxboro, Stonely mud Able 1997 SL, range 138-Island creeks.

390 mm, Marsh creeks and mostly YOY deeper (4-9 m) bay shoals.

Szedlmayer et 60-326 mm TL Great Bay, Little June-Sept 89 June: mesohaline subtidal creeks al. 1992 (YOY)

Egg Harbor subtidal creeks 90-98% mud July: shallow mudflats/dredged channels Aug-Sept: marsh creeks Szedlmayer 210-254 mm Great Bay, Little Aug-Sept 90 Schooner Creek mean 23.5'C and Able TL Egg Harbor (optimum?)

1993 (age 0)

' Laboratory study Adults: no pertinent informainon

Page 33 Table 2. cont'd.

Life Stage Authors Salinity Dissolved Light Currents Prey Predators Notes Oxygen Primary prey: calanoid TRANSFORMING Grover copepod Temora LARVAE 1998 longicornis, indicating pelagic feeding. Evidence of benthic feeding observed only in late-stage metamorphs (stage H+ and I), where prey included polychaete tentacles, harpacticoid copepods.

Less burying in Keefe and Prefer Increased presence of decapod Time to completion Able 1993, burying burial at shrimp Crangon, of metamorphosis 1994 during flood tide.

increased burying in temperature daylight.

presence of dependent.

mummichog Fundulum.s Szedlmayer et al. 1992 11-16 mm TL Witting and transforming larvae Able 1993 are vulnerable to predation by a large size range of shrimp (Crangon septemnspinosa, 50 mm TL) in NJ estuaries.

Found mostly during JUVENILES Rountree mean 29 ppt summer. Abundance and Able varied significantly 1992a between years.

Maximum abundance of fluke during peak in Menidia menidia abundances.

Moving In order of abundance:

Creeks are foraging Rountree mean 27ppt, with the Atlantic silversides habitat. Prey and 1992b range 23.5-tides. Tidal Menidia menidia, composition exhibits 30 ppt movements mummichogs Fundulus a seasonal influence.

associated heteroclitumv, shrimps Frequency of with Palaemonetes vulgaris Menidia declines foraging -

and Crangon during Aug, Sept, stomachs

.septemspinosa.

Oct while Crangon fuller on rises.

ebb tide.

Nocturnal Rountree range 22-33 sampling:

Mostly Preference for creek and Able ppt extensive caught on mouths and tidal 1997 use of ebb tides creeks rather than shallow (sampling bay shoals. Peak habitats during night catch in late during hours).

July/Oct.

night-time.

Szedlmayer subtidal High use of creek et al. 1992 creeks avg.

mouths.

20 ppt Selective tidal Szedlmayer mean 29 ppt mean 6.4 selective transport, feeding, and Able (optimum?)

ppm tidal stream optimal 1993 (optimum?)

transport environmental conditions cause movement. High use of creek mouths.

Laboratory study Adults: no pertinent information

Page 34 Table 3. Habitat parameters for summer flounder, Paralichthys dentatus: inshore Delaware.

Life Stage Authors Size Range Geographic Time Period Habitat Substrate Location JUVENILES Malloy and Collected 41-80 Roosevelt Inlet and Inlet: Nov 89-Apr 90 Estuarine marsh creeks Targett 1991 mm TL for Indian River Bay Bay: Feb-June 89-90 0.5-1.5 m in depth.

experiment.

Malloy and 18-80 mm TL Indian River Bay Jan-June 91/92 Targett 1994a Malloy and 18-80 mm TL Indian River Bay Jan-June 92 Protected beach close to Intermediate size grains Targett 1994b muddy channel, with ephemeral macroalgal cover.

Timmons 7.6-24.9 cm TL Rehoboth Bay, June 92, Aug 92, Attracted to the algae Prefer sand to shell 1995 Indian River Bay Nov 92, Mar 93 Agardhiella tenera rubble or algae. I because of the presence Captured in sand and of prey, but remain in mud.

nearby sand to avoid predation. Collected in water depths between 0.5-5.5 m.

ADULTS Smith and

> - 28 cm TL Delaware Bay Aug 66-Nov 71.

Captured from the Daiber 1977 Most captured May-shoreline to 25 m deep.

Sept, a few

[juveniles] have been caught in the deeper parts of the Bay in every winter month.

Laboratory study Transforming larvae:,no pertinent information DO., Currents. Light: no pertinent information

Page 35 Table 3. cont'd.

Life Stage Authors Temperature Salinity Prey Predator Notes Mortality was 42% after JUVENILES Malloy and 16 days at 2-3°C; > 3oC, Collected at 24-30 Fed locally caught mysid The extended period Juveniles that Targett 1991 all fish survived.

ppt. Experimental shrimp Neomysis americana in of time spent at small arrive in northern Mortality highest in fish < salinity variation experiment.

sizes may increase Mid-Atlantic 50 mm TL in < 3YC water: (10-30 ppt) had vulnerability to Bight estuaries in all fish > 65 mm survived no effect on predation.

the fall, in

< 2.5"C for 2 weeks, feeding, growth or advance of winter Growth rates were the survival.

temperature same between 2 and I0"C.

minima, may be Mean growth rate able to grow past increased to 2.4% per day a lower critical at 14"C and 3.8% per day size, thus at 18'C.

increasing survival.

Mortality ofjuveniles Can survive 14 days with no Malloy and depends more on rate of food at 10-16"C (typical Targett temperature decline than temperature at settlement).

1994a on final exposure Prey availability is important temperature. No growth at to growth, Fed locally caught temperatures mysid shrimp N. americana in

< 9"C. DE fish more experiment.

tolerant of low temperatures (1 -4"C) than NC fish.

Low densities of mysids (one Extended period of Malloy and 2.6-20"C of the dominant prey items) time spent at small

< 50% maximum Targett until June.

sizes (13-25mm TL) growth in 1994b could increase May/early June.

vulnerability to predation.

Timmons June: 22-281C, Range: 12-28 ppt. Rehoboth flounder fed on In caging experiments, Suggests that 1995 August: 17-25'C, Salinities were shrimp Paleomonetes blue crabs were least macroalgal November: 7-12"C, constantly lower vulgaris, plus porturid and able to prey on the systems appear to March: 9-13"C in Indian River blue crabs. Indian River fish flounder in cages with act as an Bay compared to fed on mysids.

sand bottoms only, but ecological Rehoboth Bay.

had an advantage in surrogate to capturing the flounder seagrass beds and in cages containing seagrass/macro-macroalgae.1 algal systems.

< 45 cm fed on invertebrates, ADULTS Smith and

> 45 cm TL ate more fish. In Appear to migrate Daiber 1977 order of % frequency of little and may be occurrence: shrimp (C.

permanent septemvpinoso), weakfish, residents.

mysids (N. americana),

anchovies, squids, Atlantic silversides, herrings, hermit crabs (P. longicarpus),

_isopods (0. praegusta).

Laboratory study Transforming larvae: no pertinent information D.O., Currents, Light: no pertinent information

Page 36 Table 4. Habitat parameters for summer flounder, Paralichthys dentatus: inshore North Carolina.

Life Stage Authors Size Range Geographic Time Habitat Substrate Temperature Location Period Wild caught and lab TRANS-Burke 1991 mean 14.7 Newport River Feb-Mar 87-reared larvae: preferred 6-20'Ci FORMING mm SL Estuary 89 sand over mud even LARVAE when prey not present.

Implies search for food to some extent restricted to sandy substrate in settling fish.

Burke 1995 11-20 mm SL Newport and Jan-Apr 88 Tidal flats, channels.

10-13'C North River Larvae concentrate on Substrate type can Burke et al. 11-17 mm SL Newport and Nov-Apr 86-shallow tidal flats (< I m), affect distribution.

1991 North Rivers 89 middle reaches of estuary. Higher probability on Fewer catches in "1.5-3 m.

sand than mud.

In spring juveniles migrate to higher salinity salt marsh.

Onslow Bay: concentrate Burke et al. Onslow Bay:

Onslow Bay, Feb/Mar in estuarine areas. Outside 1998 9-15 mm SL, includes 1995 the estuary in the surf zone transforming nearshore and in deeper habitats of

larvae, waters; the Bay, larvae were Beaufort Beaufort Inlet present only during the Inlet: 11-15 and Newport immigration season.

mm SL, all at River estuary.

Within the Newport stages estuary initial settlement G - 12.

appears to be concentrated Newport in the intertidal zone River estuary:

rather than in adjacent 11-21 mm deeper areas.

SL.

Deubler and 12-15 mm SL Bogue Sound Feb-61 White 1962 7-18"C, higher Hettler et al. 12-15 mm SL Beaufort Inlet Nov 91-Apr Tidal channel, 6m deep.

abundance with 1997 92, nightly increased temperatures.

Tidal salt marsh and Weinstein et 7-34 mm SL Cape Fear Mar-Apr creeks, shallow open al. 1980a River Estuary water.

Grain size variation 16.8-21.1]C Weinstein et mean 13.6 Cape Fear Sept 77-Aug Tidal creeks, shallow among sites: fine sand al. 1980b mm River Estuary 78 marsh.

(58-93%), medium sand (7-41%), mud (I-14%).

Pamlico Sound, 1957-1966, 2-22"C, most Williams Neuse River biweekly, at abundant at 8-and Deubler night 16'C.

1968b Laboratory study Adults: no pertinent informaition D.O.: no pertinent information

Page 37 Table 4. cont'd.

• Life Stage Authors Size Range Geographic Time Habitat Substrate Temperature Location Period Tidal flats and JUVENILES Burke 20-60 mm SL Newport and Jan-Apr 88 channels, juveniles 10-133C 1991, 1995 North Rivers migrate to salt marsh.

Shallow: < 1 m mean low tide.

2-20'C: Increase in Malloy and 18-80 mm TL lower Newport Jan-June temperature = increase in Targett River 91-92 feeding rate, maximum 1994a growth rate, gross growth efficiencies. Increased rate of temperature decline = decreased survival.

< 7-9'C no positive growth rates.

Sandy salt marsh Predicted growth rates Malloy and 18-80 mm TL Newport River Jan-June (adjacent to Spartina higher at muddy beach 8-23°C (Feb-June)

Targett Estuary 92 alterniflora marshes) site in May.

1994b and muddy beach.

10-30"C, increase in Peters and temperature = increase in Angelovic ad libitum feeding rate 1971 and growth efficiency.

Little growth at low temperatures, fastest growth rate at 20-25'C.

Specific growth rate 5% at 15'C, 10% at 20'C.'

Migration to estuary in Powell

,18-224 mm Pamlico Sound May 71-February: body weight 1982 TL, mean at July 72 increases 5%/day. After end of I st yr:

February increase in males 167 temperature = a decrease mm, females in growth rates. Late fall 171 mm TL growth negligible. June:

2% increase body weight

/day, August: 1%.

Range 70-250 Powell and mm TL. 8-16 Pamlico Sound Aug 71-Most abundant in Greater abundance with Warm temperatures and Schwartz mm when July 72 eastern and central sand, or sand/shell, intermediate/high 1977 entering Pamlico Sound scarce where mud salinities = increased estuary, 90-(relatively high predominates.

growth rate.

100 mm at salinity), close to inlets.

first spring, Ist yr.

juveniles 170 mm by Dec.

Aug 71-Powell and 100-400 mm Pamlico Sound July 72, Dominant in lower Increased temperatures =

Schwartz TL (84% of and adjacent

monthly, estuary.

increased food 1979 captures 100- estuary daylight consumption for 200 mm TL) sampling overwintering juveniles.

Ross and 21-320 mm Pamlico Sound Mar 81-YOY on seagrass bed.

fine sand Epperly SL Nov 82 1985 Laboratory study Adults:,to pertinent information D.O.: no pertinent information

Page 38 Table 4. cont'd.

Life Stage Authors Salinity Light Currents Prey Predators Notes TRANS-Burke 1991 16-34 ppt r Sand preference of FORMING metamorphosing larvae in LARVAE laboratory corresponds to older fish in wild.

Burke 1995 21-32 ppt Polychaete tentacles most important, plus polychaetes and harpactacoid copepods. Increasing importance of polychaetes and clam siphons with increasing development.

Predator Burke et at. 19-31 ppt avoidance by 1991 burying in sandy substrate.

During flood tides, highest Observations of tidal rhythm of Burke et al. 34 ppt larval densities at mid-depths activity of wild-caught flounder' 1998 within water column; during and vertical shift into water ebb tide, highest densities at column during slack tide suggests bottom. Position in water behavioral component to tidal column dependent on tidal stream transport. High activity stage; shift in during ebb tide' suggests most distribution/abundance active behavioral component of associated with shift in tidal TST involves avoidance of stage, indicating flounders enter advection by ebbing tide rather Onslow Bay by tidal stream than movement into water column transport. Wild-caught larvae and transport by flood tide. Lack had regular paitern of activity of tidal activity pattern in lab-correlated with tidal cycle; peak reared flounder' suggests activity associated with ebb development of tidal rhythm tide'. Lab-reared flounder: no dependent on exposure to clear pattern of activityt.

physical variables that are correlated with the tide.

Deubler and 10-30 ppt:

Salinities commonly found in White 1962 increase in lower estuary allows optimal salinity =

growth.

increase in body wt; 40 ppt =

decrease in body wt.

I Hettler et 24-36 ppt More abundant mean density = 2 larvae/100m"*

at. 1997 in catches later (Dec 31-Apr 15) at night.

Weinstein Night catches > Marsh migration aided by Despite intensive tidal flows et al. 1980a day catches. At surface movement on flood tides maintain preferred position in night at night, settle to bottom on ebb.

estuary by specific behavioral concentration at responses.

surface >

concentration at other depths.

Weinstein 1.7-24.9 Distribution influenced by salinity et al. 1980b ppt; greater gradients and to lesser extent by occurrence substrate characteristics.

in mid/higher salinities.

Williams

.02-35 ppt.

and Deubler IS ppt 1968a optimum I

Laboratory study Adults: no pertinent information D.O.: no pertinent information

Page 39 Table 4. cont'd.

Life Stage Authors Salinity Light Currents Prey Predators Notes Visual Active predator; ate Diets of summer and southern JUVENILES Burke 21-32 ppt predators.

primarily infaunal flounder similar during settlement 1991, 1995 Feeding crustaceans, polychaetes, when distributions overlapped. Diets largely invertebrate parts.

diverged prior to segregated restricted Polychactes (primarily distribution. Spionid prey to daylight.

spionids) most important.

Streblospio benedicti abundant in marsh; may explain juvenile migration to marsh.

NC juveniles higher maximum Malloy and 30 ppt Winter food limitation less growth rates and growth efficiencies Targett important than variability of than DE fish at temperatures from 6-1994a temperature minima.

180C. NC fish less tolerant of low temperatures (I -4'C) than DE fish.

Low abundance of NC Malloy and mysids from May into Predicted growth rates = 2-5%/d Targett summer might explain Feb-April. Marsh juveniles severely 1994b growth limitation in marsh growth limited after April with juveniles during May.

temperatures 18-20'C.

Increasing abundance of other prey (polychaetes, amphipods) may account for favorable juvenile growth in muddier site during May.

Maximum caloric growth efficiency Peters and 5-35 ppt;.

predicted at 21'C, 24ppt salinity Angelovic relatively little and 78% ad libitum feeding. All 1971 effect on ad body processes including feeding libitum feeding increases with temperature to an rate.'

optimum; > optimum, increasing temperature becomes detrimental.

Decrease in growth with increase in Powell temperature probably due to intrinsic 1982 (not environmental) factors.

Most abundant Powell and moderate/high Shallow Juveniles overwinter in estuary Schwartz salinities 18-35 waters near (adults migrate to ocean).

1977 ppt. Spatial inlets (fast Distribution governed primarily by segregation flowing).

benthic substrate and salinity.

with southern Pamlico Sound unusual: solar-lunar flounder:

tides immeasurable; salinities increase in uniform in much of sound.

salinity =

increase in summer flounder abundance.

Young flounder fed mostly Powell and Dominant in on mysids and fishes Southern flounder diet compared:

Schwartz higher throughout the year. As size reverse importance was found -

1979 salinities.

increases diet consisted of fishes, then mysids.

shrimps and fishes in similar quantities. Feeding rate decreases in winter.

Distribution Ross and significantly Epperly correlated with 1985 salinity, range 22-28 ppt, optimal 22-23

_ ppt.

' Laboratory study Adults: no pertinent information D.O.: no pertinent information

Page 40 Table 5. Summary of life history and habitat parameters for summer flounder, Paralichthys dentatus: inshore New Jersey, Delaware and North Carolina.

Life Stage Size Geographic Habitat Substrate Temperature Location.

TRANSFORMING - > 8 - < -18 NJ: Great Bay, Shallow tidal flats and Sand preference Time to completion of LARVAE mm SL Little Egg Harbor; marsh creeks, metamorphosis temperature NC: Pamlico Sound dependent. Increased (No pertinent and Cape Fear temperatures = shorter information for DE) estuaries, metamorphosis. Mortality from < 2-4"C. No effect of starvation on mortality or time to completion of metamorphosis at temperatures

< 10C.,

JUVENILES

- > 20 mm -

NJ: Great Bay, Lower estuary: flats, NJ: found on muddy DE: > Y3C, all fish survived.

- < 28 cm TL Little Egg Harbor; channels, salt marsh creeks, bottoms. NC: often greater NC: Feeding rate, growth rate DE: Delaware and eelgrass beds. Possible abundances on sand or mixed and efficiencies increase with Indian Rivers, preference for creek mouths substrates. Scarcer on mud.

increasing temperatures.

Rehobeth Bays; (NJ) and inlets (NC).

DE: Sand preference.'

< 7-9'C = no positive growth NC: Pamlico Creeks are foraging habitat. Captured on sand and mud.

rates (both DE, NC fish); 20-Sound, Cape Fear, DE: Attracted to macroalgae Substrate preference possibly 25'C = fastest growth rates.

and adjacent because of the presence of overrides salinity preference. NC fish higher maximum estuaries, prey, but remain in nearby growth rates/growth sand to avoid predation.

efficiencies at 6-18"C than DE fish.'

DE juveniles show greater tolerances for low temperatures than NC*

juveniles. Mortality of juveniles depends more on rate of temperature decline than on final exposure temperatures.1 ADULTS

~> 28 cm TL Delaware Bay Captured from the shoreline to 25 m.

(No pertinent information for NJ, NC) 1 Laboratory study D.O.: no pertinent information References New Jersey: Rountree and Able (1992asb. 1997), Szedlmayer et al. (1992). Keefe and Able (1993, 1994), Szedtmayer and Able (1993), Witting and Able (1993), Grover (1998)

Delaware: Smith and Daiber (1977), Malloy and Targett (1991). Malloy and Targett (1994a,b). Timmons (1995)

North Carolina: Deubler and White (1962), Williams and Deubler (1968b). Peters and Angelovic (1971), Powell and Schwartz (1977, 1979), Weinstein el al. (1980a,b),

Powell (1982). Ross and Epperly (1985). Burke (1991), Burke et al. (1991, 1998). Malloy and Targen (1994a.b). Burke (1995). Hettler et al. (1997). Walsh et al. (1999)

Page 41 Table 5. cont'd.

Life Stage Salinity Light Currents Prey Predators TRANSFORMING Salinities found in Prefer burying NJ: Increased burial at Calanoid copepod Burying behavior LARVAE lower estuaries during daylight.'

flood tide;' however, NC: Temora longicornis --

determined by presence of optimal for growth: Night active.

possible surface or mid-indicates pelagic feeding. particular predator.'

(No pertinent 10-30 ppt.;

depth movement on Benthic feeding in late-NJ: 11-16 mm transforming information for DE) Increasing salinity =

flood, settlement on ebb.

stage metamorphs, prey larvae vulnerable to increased body Position in water column includes polychaete predation by large size weight [Weinstein dependent on tidal stage, tentacles, harpactacoid range of shrimp C.

el al. 80b:

flounders utilize tidal copepods, polychaetes; septemvpinosa (- 11-50 Distribution stream transport mm TL)'

possibly influenced (behavioral component more by salinity suggested). Peak activity than by substrate.]

associated with ebb tide'.

JUVENILES More abundant in Visual predators, Selective tidal stream Smaller juveniles:

DE: In caging experiments, higher salinities of feeding restricted to transport. Feeding, infauna (e.g.,

blue crabs were least able to 18-35 ppt. Possible daylight, but NJ optimal environmental polychaetes). Larger prey on the flounder in preference, but study (Rountree and conditions cause juveniles (- > 100 mm cages with sand bottoms interactions with Able 97) shows movement.

TL): fish, shrimps, crabs; only, but had an advantage substrate increased night-time DE: No pertinent often tied to abundance in capturing the flounder in preferences.

catches in marsh information, in environment.

cages containing DE: Experimental creeks.

macroalgae.1 salinity variation DE: No pertinent NJ, NC: No pertinent (10-30 ppt) had no information, information.

effect on feeding, growth or survival.'

ADULTS

< 45 cm fed on invertebrates, > 45 cm (No pertinent TL ate more fish. In information for NJ, order of % frequency of NC) occurrence: shrimp (C.

septemspinosa),

weakfish, mysids (N.

americana), anchovies, squids, Atlantic silversides, herrings, hermit crabs (P.

longicarpus), isopods (0. praegusta).

Laboratory study D.O.: no pertinent information References New Jersey: Rountree and Able (1992a.b. 1997). Szedlmayer et al. (1992), Keefe and Able (1993.1994), Szedlmayer and Able (1993). Witting and Able (1993), Grover (1998)

Delaware: Smith and Daiber (1977), Malloy and Targett (1991), Malloy and Targett (1994a,b), Timmons (1995)

North Carolina: Deubler and White (1962), Williams and Deubler (1968b), Peters and Angelovic (1971). Powell and Schwartz (1977, 1979), Weinstein et al. (1980a.b),

Powell (1982). Ross and Epperly (1985), Burke (1991). Burke ei al (1991, 1998). Malloy and Targett (1994ab), Burke (1995), Hettler et al. (1997), Walsh et al. (1999)

Page 42 Table 6. Summer flounder catch and status (weights in '000 mt, recruitment in millions, arithmetic means).

Year 1989 1990 1991 1992 1993 1994 1995 1996 Maxz Min2 Mean' Commercial landings 8.1 4.2 6.2 7.6 5.7 6.6 7.0 5.8 17.1 4.2 9.7 Commercial discards 0.7 1.2 1.1 0.7 0.8 0.9 0.3 0.5 1.2 0.3 0.8 Recreational landings 1.4 2.3 3.6 3.2 3.5 4.1 2.5 4.7 12.7 1.4 5.4 Recreational discards 0.A 0.6 1.1 0.9 1.8 1.4 1.8 1.6 1.8 0.1 1.1 Catch used in assessment 10.4 8.3 12.0 12.3 11.9 13.0 9.5 10.5 27.0 8.3 16.6 Spawning stock biomassr 5.2 7.5 5.8 7.3 9.3 12.4 17.3 17.4 18.9 5.2 12.4

]At the peak of the spawning season (i.e., November 1). 2Over period 1982-1996.

Page 43 Figure 1. The summer flounder, Paralichthys dentatus (from Goode 1884).

Page 44 760 740 720 700 680 660

• P resent

i:,::*.:... ::=:

420 Number Fofutainde amld:251 Fish Caught/station (excluding 0 catchies):

Mean: 8 Min: 1 Max: 716 Length (cm):

Mean: 34 Min: 4 Max: 82 Figure 2. Overall distribution of adult and juvenile summer flounder in NEFSC bottom trawl surveys in autumn (1963-1996), winter (I 964-I 997),ý spring (1968-1997), and summer (1964-1995) [see Reid et al. (1999) for details].

Page 45 3401ý'-

Figure 3. Distribution and abundance of juvenile (< 28 cm TL) and adult (> 28 cm TL) summer flounder by season, collected during NEFSC bottom trawl surveys during autumn (1963-1996), winter (1964-1997), spring (1968-1997) and summer (1 964-1995) [see Reid et al. (1999) for details].

Page 46 I.

I Figure 3. cont'd.

Page 47 Adults: > 28cm TL SPRING SUIVTVER 70-65-60-55-50-45-40-S35-uj -

WU30 25-20-15-10-5-

A oi STATION'S N61259 8 CATCH-ES N-4534 75-70-65-60-55-50-

~45-w 40-0° 35.

r0 30-25-20-15-10-5-

0 STA11Or' N=1 1

• CATCHES N6745 Al llll--J i i J i i i i*

i i i i J i i JJ i i i i i i iii i J i i I

I 0

DEPTH (i) 0 DEPTH (m)

WINTER FA.L 70 65 60 56 50 45 t40 035 L30~

25.

2D 15.

10.

5.

o STA11T'S N6198 M CATCHES N=1 1630 70 65 60 55 50 45

~40 LLI 035 w 30 a_

25 20 15 10 5

0 0 STA11ONS N6432 0 CATCH-ES N=9418 Im I I,,4,m I1I1.1'.nI-IIII II I

0 0

04 0

DEPTH (mn)

DEPTH (m)

Figure 4. Seasonal abundance of adult summer flounder relative to water depth based on NEFSC bottom trawl surveys

[ 1963-1997, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/I 0 m2).

Page 48 Summer Flounder Summer Flounder i..

Mass. Inshore Trawl Survey Mass. Inshore Trawl Survey Autumn 1978 - 1996 Spring 197 8-1996 Adults (>=28cm)

Adults (>=28cm) 7 4..........

I,

t. 5.

to 5 to

'o

'..5 to. 1 390 10 to 15 t

to t 25I 015 to20 025 to 50 20 to 32 0 50 to 83

~~...........

A:ji F.

Figure 5. Distribution and abundance of adult summer flounder in Massachusetts coastal waters from shore out to 3 miles during fall (typically September) and spring (typically May), based on bottom trawl surveys by the Massachusetts Division of Marine Fisheries from 1978-1996 (Howe et al. 1997; Reid et al. 1999). Collections where no adults were caught are shown as small x's.

Page 49 Summer Flounder Adults (>= 28 cm)

Figure 6. Seasonal distribution and relative abundance of adult summer flounder collected in Narragansett Bay during 1990-1996 Rhode Island Division of Fish and Wildlife bottom trawl surveys of Narragansett Bay. The numbers shown at each station are the average catch per tow rounded to one decimal place [see Reid et al. (1999) for details].

Page 50 I

Winter V.

I I I I.

I.

I I.

I Ig..

I I I Iv I

I 25 27 29 31 33 35 37 39 4143 45 47 49 51 5-4-

3-2' 1

0-53 55 57 59 61 63 65 67 69.

Spring U I.&,

1-i 25 272931 33 41 43 45 47 49 51 53 55 57 59 6163 65 67 69 71 15" 12' 9-6-

3' 0 -

I Summer I

IV --.

UE I& 1.P4M 5 27 29 3133 3537 394143 4547 495153 5557 596163 656769 71 15-12' Autumn 9"

6-3' 0

25 27 29 31 33 35 37 39 41 43 45 47 49 5153 55 57 59 6163 65 67 69 71 Total Length (cm)

Figure 7. Seasonal length frequencies of summer flounder caught in Narragansett Bay during 1990-1996, from the Rhode Island Division of Fish and Wildlife Narragansett Bay bottom trawl surveys of 1990-1996.

Page 51 Adults (_ 28 cm) 30

[-

E] Stations 20 U Catches Winter 10 20 30 40 50 60 70 80 90 100 110 120 25-20-Spring 15 0 J 1

' M=

10 20 30 40 50 60 70 80 90 100 110 120

.30 20-lSummer 10 lOL 10 20 30 40 50 60 70 80 90 100 110 120 30' Autumn 20-

• .10 0

10 20 30 40 50 60 70 80 90 100 110 120 Bottom Depth (ft)

Figure 8. Seasonal abundance of adult summer flounder relative to bottom depth based on Rhode Island Division of Fish and Wildlife bottom trawl surveys of Narragansett Bay, 1990-1996. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all catches.

Page 52 Figure 9. Distribution and abundance of juvenile and adult summer flounder (12-76 cm TL) collected in Long Island Sound, based on the finfish surveys of the Connecticut Fisheries Division, 1984-:1994 (from Gottschall et al., in review).

Circle diameter is proportional to the number of fish caught, and is scaled to the maximum catch (indicated by "max="

or "max>"). Collections were made with a 14 m otter trawl at about 40 stations chosen by stratified random design.

Page 53 105210-n'=250 Trows-lOG August n =487 Tows-132 10-I-I TOlfh-i228n--52iMayI 10 W14 10D

'ooo 10 I-

.h Lil Junle n--41 7w-133 Juty n-170 lwow8--63 September n-S8l Tows-290 Octeb*

n-652 Towms

=288 November n-S9 TOWS-49 d

u b11111111 1"

U.I 12 16 2D 24 28 32 36 40 44 48 52 5Q W0 64 68 72 76 12 16 20 24 218 32 36 40 44 48 52 56 6D 64 68 72 76 Figure 10. Length frequency distribution (cm) of juvenile and adult summer flounder collected in Long Island Sound, based on the finfish surveys of the Connecticut Fisheries Division, 1984-1994 (from Gottschall et al., in review).

Page 54 Summer Floun Hudson-Raritan Es Fall 1992-199 Adult. (>28 cm der

tuary, 6

NEW YORK

0)

'an 0

NEW JERSEY Summer Flounder Hudwn-Raritan Estuary Sprin6 1992-1997"r Adults (>28 cm) y 0

Nofr" 0

low '99

• 30.6o 69 NEW JYoRK 4usd

~I

~

S.

11,,4 NEW

• 50 JERSEY 1

~

\\

S 201>29 Figure I1. Distribution and relative abundance of adult summer flounder collected in the Hudson-Raritan estuary during Hudson-Raritan trawl surveys in fall (October-December, 1992-1996), winter (January-March, 1992-1997), spring (April and June, 1992-1996), and summer (July and August, 1992-1996) [see Reid et al. (1999) for details].

Page 55 Cd I-Newark Bay Summer Flounder (Paralichthys dentatus) 40*

May 1993 201 N=28.

0 0

40 -June 1993 20 N = 104 40-4-

"July 1993 20-N = 80 401 Aug 1993 2011 N=40 40-1 Sept 1993 N = 10 40-Oct 1993 204-Nt= 1 @,26.

40-Nov 1993 20 N=0 40-1 20:1 Dec 1993 40-20-Jan 1994 N=O 401] "Feb 1994 20 N=0 40-40 Mar 1994 20-N = 0 401.

April 1994 20-

• N= 15 15 20 25 30 35 40 45 50 55 Length (cm)

Figure 12. Length-frequency distributions of juvenile and adult summer flounder from Newark Bay, New Jersey.

Collected using an 8.5 m otter trawl from May 1993-April 1994 (Wilk et al. 1997).

Page 56 1987 ln=139l 0

0

'[...

.i~ijiiiji+*

III**

+:

!*iz

'v :ii :

0 00 00

• `}*:*ii~!*ii7jii.*J+`+711*~i7J*:**i170 0i~*ii+i***

0T?

iT,;): *

++7+++++i

++%

+::++:++

+++++++g++++++++L

+++++i@

1++:i+'i+++:!+7++:*

+? ++7+78:

+

[+++++7

++ + + '++ ++ ++ + +++++++++++++++++:

.*0

+

+:++:!*+*::!+8

5+::*'+*!:: :

+ : :::

08 ::

1990 MARCH

@0 0:0 00 000000 00

0. o

!i!!!*..

o

!i 0

o7:::f::!,p 0

+

I 0

@00 0

00 000 0

0 0 e0 02 0

E 0,

0"NUMBER OF~

FISH 0

SYMBOL I TOW 0

0 6-10 11-20 0~

21-50 51-100 Figure 13. Distribution and abundance of juvenile and adult summer flounder in Pamlico Sound, North Carolina and adjacent estuaries during years of high (1987) and low (1990) abundance. Collections were made by Mongoose trawl at stations chosen by stratified random design. Data based on North Carolina Division of Marine Fisheries trawl surveys, 1987-1991. Adapted from Able and Kaiser (1994).

Page 57 1990 SEPTEMER

• ~

o0 Figure 13. cont'd.

Page 58 Summer flounder 1 Summer flounder (Paralichthys dentatus) 44 (Paralichthys dentatus)

Eggs MARMAP Eggs 4

MARMAP Ichthyoplamnkton Surveys V

AMPIchthyoplankton Surveys 43-61-cm Bongo Net; 0.505-mm mesh

'61-cm Bongo Net; 0.505-mmm 1978 to 1907 Z;,

January, 1978 to 1987 (Sep. Out, Nov. Dee. Jan. Ape May) hNumber of loss = 433. with eggs = 4 42 Nuwhorofiosu, witthoegggp389 "Y

42-Monthly Meon Density =002Eggs/lOwn' 41

\\

41-40-40-i 17-,

'7- _

3 36 00o9 36-0 35r i

35

)2.

4to 76 75 74 73 72 71 70 69 68 67 66 65 76 75 74 73 72 71 70 69 68 67 6

Summer flounder Summer flounder (Paralichthys dentatus)

(Paralichthys dentatus)

(Pa Eggs Eggs MARMAP lchthyoplanklon Surveys e"

MARMAP Ichthyoplankton Surveys 43-61-cm Bongo Net; 0.505-mm mesh 3-61-cm Bongo Net; 0.505-mm mesh April, 1978 to 1987

" V V

May, 1978 to 1987 Numbero(lowss= 1020. witheggs= I II Nomceolos= 1065. witeggs=4 42-Monthly Moan 13-ity =0.023 E 42-Moathly Mean Density0.0Es 4 l

.Non i

Non I040-t 39-39-1 '

a 38-5 38-37-o:

tot0 37t 9

3 16to2 76 75 74 73 7'2 7'1

7) 69 60 67 66 65 76 75 74 73 72 71 70 69 66 67 6

Figure 14. Distribution and abundance of summer flounder eggs collected during NEFSC MARMAP offshore ichthyoplankton surveys from Cape Sable to Cape Hatteras during 1978-1987 [see Reid et al. (1999) for details].

Page. 59 45-I Summer flounder (Paralichthys dentatus)

Eggs MARMAP tchthyoplankton Surveys 43-61-cm Bongo Net: 0.505-mm mesh September, 1978 to 1997 Number o.f lows = 747. with eggs = 24),

"Mthly MessnrIw.ity = I.56Eggs/lttn' 39-1 37-None

• I t t 10 S(Ito <-100 0

IM lio 116 36"'

35-74 73 72 71 70 69 69 67 66 45" 44 43-Summer flounder (Paralichthys dentatus)

Eggs MARMAP Ichthyoplankton Surveys 61-cm Bongo Net; 0,505-mm mesh November. 1978 o997 Numher f loews = 915. with eggs = 1 V6 42-1 Monthly Mean Demily = 5.660 Eggs/l00u 41-40-37-1 SNo~ne

• I

':<10 0

10lo <100)

SIM) lo 27 9

36"1 74 73 72

' 71

70) 69 66 67 66 65 Figure 14. cont'd.

Page 60 w

SOUTHERN NEW ENGLAND LL 100.

it.

0:

I..J u) 100 IL 0

04E= 100 NEW JERSEY 0-,

100.

ILI 0

W 100 DELMARVA PENINSULA z

0-NS w 100 100 VIRGINIA CAPES I

TO CAPE HATTERAS 0:

NS 100.

JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN Figure 15. Monthly abundance of summer flounder eggs by region from NEFSC MARMAP offshore ichthyoplankton surveys from Cape Sable to Cape Hatteras during 1979-1981, 1984, and 1985 [see Reid etaaL (1999) for details]. NS =

no samples. Adapted from Able and Kaiser (1994).

Page 61 Summer Flounder Eggs Q) 100 8o 60 40 20 0

50 40 30 20 10 0

35 30 25 20 15 10 5

0 60 50 40 30 20 10 0

50 40 30 20 10 0

100 90 20 10 0

80 70 60 30 20 10 0

September Stations Egg Catch October Lit01 November

~ Ij

~December I

Bottom Depth (m), Interval Midpoint Figure 16. Abundance of summer flounder eggs relative to water depth based on NEFSC MARMAP offshore ichthyoplankton surveys [1978-1987, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/10 M2).

Page 62 I I I

f I

I I

I 45-:-

1 1

1 1

1 L

Summer flounder (Paralichthy's dentatus)

Larvae MARMAP Ichthyoplankton Survt 6 1-cm Bongo Net; 0.505-mm me 43-1977 to 1987 (Sop, O, No, Dee, Jn. Feh, Mar, Ap, M Numbhcr of 1ows = 9459. with larvae 42-40 4

eys*

sh

.y)

Lr-c)I 10ns I toolo 16101-(l 0

fOnlo 159 76 75

.74 73 72 71 70 69 68 67 66 65 45-L -

t J Summer flounder (Paralichthys dentatus) 44-Larvae MARMAP lchthyoplankton surveys MARMAP lchthyoplankton Surveys 61-cm Bongo Net: 0.505-mm mesh 4:

, *\\-.

j 61-cm Bongo Net; 0.505-mm mesh 43-February, 1977 to 1987 March, 1977 to 1987 m Monthly Mean Density = 0.31 Lurvun/I0.',

>~-

Monthly Mean Denily =0.19 Luesuedl~ns 5

4-Nttmhn ofltos=6866 sitill larve-24 42 Nuetnheoftow-10l3l. wills 1uru 19 39-439-36-l 36-35 35 76 75 74 73 72 71 7()

4, 6'8 6,7 6'6 65 76 75 74 73 72 71 7'0 69 64 67 6

Figure 17. Distribution and abundance of summer flounder larvae collected during NEFSC MARMAP offshore ichthyoplankton surveys from Cape Sable to Cape Hatteras during 1977-1987 [see Reid et al. (1999) for details].

Page 63 45-!

J _

Summer flounder (Paralichthys dentatus) 44-

ýLarvae MARMAP Ichthyoplankton Surveys 61-cm Bongo Net; 0.505-mm mesh 43 April, 1977 to 1987 Monthly Moon D.n.ily= 0.I I L -v ae./10 m Nmnher of tows, = 1281. with larvae = 23 %

42-41-N 40 39-3.1'ý rv None toolS 1Sto 25 76 75 74 73 72 71 70 69 68 67 45-44-4 3 -

42-41-40-Summer flounder (Paralichthys dentatus)

Larvae MARMAP Ichthyoplankton Surveys 61-cm Bongo Net; 0.505-mm mesh September, 1977 to 1987 Monthly Moan D enity = 0.14 Larvwe/l()mh 45-44-43-42-Summer flounder (Paralichthys dentatus)

Larvae MARMAP Ichthyoplankton Surveys 61-cm Bongo Net; 0.505-mm mesh October, 1977 to 1987 Monthly Moan Derity = 2,96 L arvae1Clnl Numboerof tow.% (47, with larvaec=

47 Number of tows =774, with larvae = 8 39-38-37-1 74 7L arv e / 10 m 74 73 72 7'1 7(5 619 69 6'7 66 65 L-ra/10m None 0

I to<10 S100Ito 121 36-[

74 73 72 71 70 69 Figure 17. cont'd..

Page 64 45_

Su (Para 44.

MARMAF 43-61-cm Bo Nov Monthly Me1 412-Number of t 42-40-39-[

I 36-l 35-inmer flounder

'lichthys dentatus)

Larvae PIchthyoplanklon Surveys ngo Net; 0.505-mm mesh' ember, 1977 to 197 an Densily = 6.15 Lurvacl10mn Y

tows =1031, w~ith larvae= 195 None

• I =o <0

• l01o<113

• i{ tmt159 76 75 73 72 71 7)1 69 6 67 Figure 17. cont'd.

Page 65 I~l0 SOUTHERN NEW ENGLAND

c.

100' 0

C14 E

NEW JERSEY 0

100

-I O

CC 100.

IL0 DELMARVA PENINSULA cc 100.

zz,<

100-

,U VIRGINIA CAPES TO CAPE HA1TERAS o-NS 1O00 JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN Figure 18. Monthly abundance of summer flounder larvae by region from NEFSC MARMAP offshore ichthyoplankton surveys from Cape Sable to Cape Hatteras during 1979-81, 1984, and 1985 [see Reid et al. (1999) for details]. NS = no samples. Adapted from Able and Kaiser (1994).

Page 66 Summer Flounder Larvae 60 40 20 0

40 20 0

40 20 0

September Statios 1

Catch

,*~

~~

9, 9, 9,*

40 December 20 40 -

January

~20 E

60 40 February 20 -]

.[

• • [

20I~

60 -March 40o620Ij 20

¶ 9A-1

-1

-- 1 60 April 40 20 40 May Bottom Depth (m), Interval Midpoint Figure 19. Abundance of summer flounder larvae relative to water depth based on NEFSC MARMAP offshore ichthyoplankton surveys [1977-1987, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/lO0 M2).

Page 67 Pre-transformation F -

F G

H-H I

Figure 20. Classification of the transformation stages of summer flounder based on degree of eye migration [adapted from Keefe and Able (1993) and Able and Kaiser (1994)]. The right and left eyes are bilateral and symmetrical in pre-transformation individuals. At the first stage of transformation, F -, the eyes are bilateral but asymmetrical with the right eye just dorsal to the left eye. By stage G, the right eye is visible from the left side of the fish. Stage H - differs from G in that the cornea of the eye is visible from the left side of the fish. At Stage H, the right eye has reached the dorsal midline. By Stage H +, the right eye has reached the left side of the head but has not yet reached its final resting place.

At Stage I, the eye is set in the socket and the dorsal canal is closed.

Page 68 2Q 107 Creek Pita EM Lachicotte EM Beresford El Inlet NOVEMBER 80 n=O 40 APRIL n = 143 r%

V

• .1 DECEMBER n=O MAY n=31 u)

U-0 M

z 20 10 JANUARY 20 n =25 10.

JUNE n = 87 I~~

16 8

8 4

0 "-"'-,

0 FEBRUARY

0 L n =245 0

0 MARCH 0n

= 134 0o n-W

=*a V.-

20 10 0

20 10 0

10 JULY n=1 AUGUST.

n=0 10 30 50 70 90 110 130 150 30 50 70 90 110 130 150 TOTAL LENGTH (mm)

Figure 2 1. Length frequency distributions for transforming larval and juvenile summer flounder collected during 1986-1987 from estuarine marsh creeks in Charleston Harbor, South Carolina, using a rotenone/block net method (Wenner et at. 1990a). Adapted from Able and Kaiser (1994).

Page 69 Summer Flounder Summer Flounder Mass. Inshore Trawl Survey Mass. Inshore Trawl Survey Autumn 1978 - 1996 Spring 1978 - 1996 Juveniles (<28cm)

Juveniles (<28cm)

Numberrrow NumberTow I to 2

.to 0 2 to 3 2 to 3 3 to4 3 to 4 9

4 to 50 t

5 to 6 5 t06 VS Figure 22. Distribution and abundance of juvenile summer flounder in Massachusetts coastal waters from shore out to 3 miles during fall (typically September) and spring (typically May), based on bottom trawl surveys by the Massachusetts Division of Marine Fisheries from 1978-1996 (Howe et al. 1997; Reid et al. 1999). Collections where no juveniles were caught are shown as small x's.

Page 70 Juveniles: <28'cm TL 70-65-60-55-50O 45-2o 4 40-15-10-5-

O SrAllT's N6713 M CATCHES W-302 70-65-60-55-50-45-

• 40-wc)35-Cr w 30-25-15-10-5-

o STAMtt'S W-84

• CATCHES N=44 DEP'H (M) o O

0 0

0 DEPTH (m)

N "

W 8 FaLL 70-65-6D0 55-50-45-40-w035-w 3D-IL 25-15-10-5-

o STAT1KS Nr&

• CATCHES N-402 70-65-60-55-50-45-I3-Z 40-035-20-15-10-5-

O STAT1CI\\IS W-M

• CATCHES N6-3 V

IL

.,,,0 IIPTH (mn) 0 0

0 0

0 0

0 0

0 EEPTH (Mn)

Figure 23. Seasonal abundance of juvenile summer flounder relative to water depth based on NEFSC bottom trawl surveys [ 1963-1997, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/10 M2 ).

Page 71

-)"NEW Summer Flounder R

YORK Hudson-Ruritan Estuay Fall 1992-1996 Juveniles (< 28 cm) o

State, a

NEW

2"t2 HERSEY.

0.6 Summer Flounder Hudson-Raritan Estuary Winter 1992-1997 f

Juveniles (< 28 cm)j SM.)

N'W NEW JERSEY 5'.9o It StoY

• 0 Oto9 10E t.6 Figure 24. Distribution and relative abundance of juvenile summer flounder collected in the Hudson-Raritan estuary during Hudson-Raritan trawl surveys in fall (October-December, 1992-1996), winter (January-March, 1992-1997),

spring (April and June, 1992-1996), and summer (July and August, 1992-1996). [see Reid et al. (1999) for details].

Page 72 Summer Flounder, 1995 NUMBER CAUGHT:

0=1 o9 ED= 10to 99 0 = 100 o 999 0 = >. 1.000 Figure 25. Monthly distribution of summer flounder in the main stem of Chesapeake Bay and in the major Virginia tributaries (from north to south: Rappahannock, York, James Rivers) from January-December 1995. Density values are the total number of individuals caught in a 9.1 m semi-balloon otter trawl with 38 mm mesh and 6.4 mm codend.

Adapted from Geer and Austin (1996).

Page 73 Summer Flounder, 1995 C

L NUMBER CAUGHT:

(D= 1 tog D= 10io 99

( = 100 to 999 S =.

1.000]

Figure 25. cont'd.

Page 74 1.71 0.9.

2.0.

1.0 A 1.4 0.07-1

• 3.0"-

01I IF

• Ir I

1.5-4.01 2.0]

001 t,

?

4

'1k~

A AR

fl1, 001I iiiw.rA A

I

/

00 0.0 A I i

/iA A 5.0.

I r

1.5 0.0 1

14 IA 0.0 75.

0.0 I

I 0.0-0.0

^

0

'00 200 300 400 500 600 LENGTH (--,m)

JANUARY 950109 -

950113 NO. CGHT.

19 MEAN SIZE 199.1 NO. MEAS.

19 S E. SIZE 9.1 NO. HAULS 40 MIN. SIZE 128 CAT./HAUL 0.5 MAX. SIZE 325 FEBRUARY 950201 950216 NO. CGHT.

42 MEAN SIZE 187.4 NO. MFS.

4Z S.E. SIZE 7.3 NO. HAULS 73 MIN. SIZE 14 CAT,/HAUL 0.6 MAX. SIZE 375 MARCH 950301 -

950313 NO. CGHT.

23 MEAN SIZE 194.2 NO. MEAS.

23-S.E. SIZE 6.4 NO. HAULS 40 MIN. SIZE 139 CAT./HAUL 0.6 MAX. SIZE 286 APRIL 950405 -

950418 NO. CGHT.

105 MEAN SIZE 225 NO. MEAS.

105 S.E. SIZE 5.6 NO. HAULS 73 MIN. SIZE 146 CAT./HAUL 1.4 MAX. SIZE 457 MAY 950503 -

950511 NO. CGHT.

176 MEAN SIZE 2-31.1 NO. MEAS.

176 S.E. SIZE 5

NO. HAULS 79 MIN. SIZE 53 CAT./HAUL 2.2 MAX. SIZE 465 JUNE 950601 950614 NO. CGHT.

165 MEAN SIZE 200.8 NO. MEAS.

165 S.E. SIZE 6.6 NO. HAULS 88 MIN. SIZE 68 CAT,/HAUL 1.9 MAX. SIZE 500 JULY 950705 -

950724 NO. CGHT.

181 MEAN SIZE 208 NO. MEAS.

I-a 1 S..

SIZE 5.8 NO. HAULS 88 MIN. SIZE 106 CAT./HAUL 2.1 MAX. SIZE 545 AUGUST 950801 -

950810 NO. CGHT.

195 MEAN SIZE 237.7 NO. MEAS.

195 S.E. SIZE 4.7 NO. HAULS 86 MIN. SIZE 55 CAT./HAUL 2.2 MAX. SIZE 557 SEPTEMBER 950905 -

950920 NO. CGHT.

210 MEAN SIZE 241.4 NO. MEAS.

210 S.E. SIZE 3.5 NO. HAULS 105 MIN. SIZE 55 CAT./HAUL 2

MAX. SIZE 504 OCTOBER

.951002 951018 NO. CGHT.

224 MEAN SIZE 269.2 NO. MEAS.

224 S.E. SIZE 3.3 NO. HAULS 105 MIN. SIZE 184 CAT./HAUL 2.1 MAX. SIZE 501 NOVEMBER 951110 -

951133 NO. CGHT.

170 MEAN SIZE 292.2 NO. MEAS.

170 S.E. SIZE 4.1 NO. HAULS 99 MIN. SIZE 189 CAT,/HAUL 1.7 MAX. SIZE 464 DECEMBER 951201 -

951213 NO. COGHT.

16 MEAN SIZE 281.9 NO. MEAS.

61 S.E. SIZE 23.1 NO. HAULS 102 MIN. SIZE 37 CAT./HAUL 0.2 MAX. SIZE 365 JAN -

DEC 950109 -

951213 NO. CGHT.

1526 MEAN SIZE 237.3 NO. MEAS.

1526 S.E. SIZE 1.8 NO. HAULS 960 MIN. SIZE 14 CAT./HAUL 1.6 MAX. SIZE 557 Figure 26. Monthly length frequency summary for summer flounder in the main stem of Chesapeake Bay and the major Virginia tributaries (Rappahannock, York, James Rivers) from January-December 1995. The y-axis represents the total number caught for each size class, in mm. The bottom plot is a summary of all fish for the entire year. Adapted from Geer and Austin (1996).

Page 75 Summer Flounder Eggs 30 September E

Stations 20 Egg Catch 0

_L__

_in_

40 30 October 20.

10 0

20 - November 10 -

0

.[

I**,

a ý9 60

'40 December 5 30 S20 610

' JL

'i i

40 -

January 30 20 10 0

1i 90 April 30 20 40 30 -

May 20 j o~

n 0

2 4

6 8

10 12 14 16 18 20 22 24 26 28 Water Column Temperature (0-200m, C)

Figure 27. Abundance of summer flounder eggs relative to water column temperature (to a maximum of 200 m) based on NEFSC MARMAP offshore ichthyoplankton surveys [1978-1987, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/10 mi2 ).

Page 76 Summer Flounder Larvae 40 -

30 20 -

10 -

o4 30 20 10 September Stations tJ.i",

P Catch October j

23°0o November 20 40 30 -

December 20 30H0 January Lii JJ 2u~.

U 30 May 20 I I 10 0

0 2

4 6

8 10 12 14 16 18 20 22 24 26 28 Water-Column Temperature (0-200m, C)

Figure 28. Abundance of summer flounder larvae relative to water column temperature (to a maximum of 200 m) based on NEFSC MARMAP offshore ichthyoplankton surveys [ 1977-1987, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/l10 M 2).

Page 77 Juveniles: < 28 cm TL SPIING 70-65-60-55-50-

• 55.

45-Q 35-10.

5-10.

o STAIIC'S N=59D I CA ES N=-259 0 STATK'S N=82 U CATC-ES W-434 H

00 wr 0W n JLi.,ML 4 I P4...........-

I4 0

2 4 6 8 10121416182D2224 262B0 E1M TBPVrEAUFE (Q FALL 0 2 4 6 8 10 12 14 16 18 2 22 24 26 29 30 BOMTvl TBVPERA11FE (C WINTER 70, 65 60.

55 50-45.

~40 035 wI 30, 25 2D 15, 10*

5.

O STAGT'NS N=680 M CATCHES N=3540 70 65 65 55 5D 45 Z 4 D w30 25 2D 15 10 5

0 O STA'11ON N6213 M CATCHES N62760 024 i 1 1 1 1.1 1

........... ' 'i1 i

6 8 1012141618202224262B30 6o01CM TBVPEPURA1E (C 0 2 4 6 8 10 12 14 16 182D22242623D 60"1CM TEMPERAR*E (Q Figure 29. Seasonal abundance of juvenile summer flounder relative to bottom water temperature based on NEFSC bottom trawl surveys [1963-1997, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/lO0 M2).

Page 78 Summer Ho Mass. Inshore Tra Juveniles 30' 20' 10" Ju~lA 25 Spring 20-15 10 5"

under E[ Staio wl Surveys Catches Adults Spring SHn lrlJlk U)

I 3

5 7

9 II 13 15 17 19 21 2-3 Bottom Temperature (C) 40-Autumn 30' 20" 10" 0~

1 3 5

7 9

11 13 15 17 19 21 23 Bottom Temperature (C) 50" 40-Spring 20" 10" 0

p Bottom Depth (m) 80 Autumn 60" 40' 2()- n po 3

5 7

9 II 13 15 17 19 21 23 Bo tto m Temperature (C) 30-20-10-0-

50" 40' 30-20" 10" Autumn

_onAfl nnIIIIl 3

5 7

9 II 13 15 17 19 21 23 Bottom Temperature (C)

Spring I~iL-nnn.ý,

b 2tlt4gg.gggW~-

I m F. F= -

Bottom Depth (m) i I Autumn 40' 30' 20" 10" I"

n n r-1,,

I m m

Bottom Depth (m)

Bottom Depth (m)

Figure 30. Abundance of juvenile and adult summer flounder relative to bottom water temperature and depth based on, Massachusetts inshore trawl surveys (spring and autumn 1978-1996, all years combined). Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/10 mi 2).

Page 79 80 60 40 20 0

80 60 40 20 Creek I

Pita J

Lachicotte J

Beresford Inlet HI.

ANUARY n = 18 EBRUARY n = 245 4

(

FE I

0 z

0!

£4"t 30 MARCH 50 n = 134 40

30.

APRIL n =143 50.40oR 20 80' MAY 60 n =31 40'

>0 20-830 JUNE 60 n=6 10-

Ž01 801 60-40 20 JULY n =1 N

~

SALI NIT

.b SALINITY (ppt)

Figure 31. Abundance of juvenile summer flounder relative to salinity in four Charleston Harbor, South Carolina marsh creeks during 1987. Fish were collected using a rotenone/block net method [data based on Wenner et al. (1990a)].

Adapted from Able and Kaiser (1994).

Page 80 oi=13 o=29 n=17 M'=6 V

U

'a iIL-i.

11-14 Iiz-Iu 17-18 21-2 mm group ( L")

co'pepods tenta~cls ficopepods Polychaetes Mrsids I~1111Amphiixsds Z -1t 7-7

/7 7/

7 >/,~/,

~2' FTT7

(~ btnr~i

~

Triv '+/-br~te fl,

.1I1~A:

ip h ipcLs S'rm YF 4 and caiD Figure 32. Relative importance of each diet item (percentage of total number multiplied by the frequency of occurrence) to: (top) different length groups of summer flounder during the immigration period, January-March 1988, in the Newport and North Rivers, North Carolina; and (bottom) to 20-60 mm SL summer flounder following segregation from southern flounder in April-June 0988 in the Newport and North Rivers, North Carolina. Relative importance values are presented as the percentage of the sum of all values for (top) each 2 mm length group and for (bottom) each species. Adapted from Burke (1995).

Page 81 100" 90-80-70-60-50-40-80/106 33/45 OTHERS OTHERS CRABS CRABS 1

(3) \\

M SHR IMP AMPHI-(3)

PODS (19)

MYSIDS r

(46)

ISOPODS (2) 95/120 92/138 OTHERS CRABS (7) OTHERS SHR IMP (5)

CRABS ISOPODS (2)

(5) 92/179 42/150 OTHERS OTHERS CRABS (6 ),

AMPHI-PODS SHRIMP (2)

(9)

MYS IDS (82)

MYSIDS (76)

AMPHI-POD)S (5)

ISOPODS (2)

MYSIDS (72)

MYSIDS (73) 46/65 OTHERS 1 CRABS/

(4)

SHRIMP (13)

AMPHI-PODS (6)

MYSIDS (83) 39/48 CRABS (3)

MYSIDS (74)

MYSIDS (60)

FISH (46)

FISH (54) 30-FISH (36)

FISH (37)

FISH (24)

FISH (44)

FISH (17) 20-FISH (37) 10-SUMMER SOUTHERN FLOUNDER FLOUNDER SUMMER SUMMER SOUTHERN FLOUNDER FLOUNDER WINTER SUMMER SOUTHERN FLOUNDER FLOUNDER FALL SUMMER SOUTHERN FLOUNDER FLOUNDER SPRING Figure 33. Percentage of volume and (in parentheses) percentage of occurrence of food items occurring in the seasonal diet of young (100-200 mm TL) summer and southern flounder from the Neuse River and Pamlico Sound, North Carolina, Numbers above each bar graph indicate the number of stomachs with food/the total number of stomachs examined. Adapted from Powell and Schwartz (1979).

Page 82 Adults: _> 28 cm TL SPRNG 50-45-40-

[I STATIKNS NOW~S M CATCHES N=4Ofl4 0 STA11TKN N6105 0 CATCHES N6727 35+

ý 30-025-

• 2D-15-10-5-

w iii(wc rL I

II-I. I. I. I. I 024 6 8 10 12 14 16 1820222422B30 BOTTOM nBPEPAn.FE (q 0 2 4 6 8 10 12 14 16 182D22 24 22B3 6011M TEIVERA~TFE (C)

FA-L WINTE:

50-45-40-35-o0-5 W

1) 5-10-5-

o STA11CNS N61672 5 CATCHES N610093 5D0

.45-40-35-

-3D-Z o25-2D-15-10-5-

0 STATI1NS=421

• CATCHES N=9D14 11111 O-ui iIi~

0 2 4 6 8 10 1214 1618 2D222425 2B30 BO11DM TVEvPEATUFE (C) 0 2 4 6 8 10121416182D2224282B30 Bo01OM TEMPERAT1JE (C)

Figure 34. Seasonal abundance of adult summer flounder relative to bottom water temperature based on NEFSC bottom trawl surveys [1963-1997, all years combined; see Reid et al. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all standardized catches (number/10 M 2).

Page 83 20" 16' 12 8

.4-]

Adults (Ž> 28 cm)

El Stations E Catches Winter RHHn_

1 3

5 7

9 11 13 15 17 19 21 23 25 27 50-40-Spring 30" 20"-o _n Hn nt n o

-t!

-1 1

3 5

7 9

1 13 15 17 19 21 23 25 27 20' 16-Summer 12' 8"

4' 0-_

-1 1

3 5

7 9

11 13 15 17 19 21 23 25 27 40-30' Autumn 20-10-0 -1 1

3 5

7 9

11 13 15 17 19 21 23 25 27 Bottom Temperature (C)

Figure 35. Seasonal abundance of adult summer flounder relative to mean bottom water temperature based on Rhode Island Division of Fish and Wildlife bottom trawl surveys of Narragansett Bay, 1990-1996 [see Reid etal. (1999) for details]. Open bars represent the proportion of all stations surveyed, while solid bars represent the proportion of the sum of all catches.

Page 84 1973-1980 (n = 243)

Other 3.4%

Crustacea Other 17.9%

Ammodytes sp. 19.8%

Unknown Fish 62.3%

Unknown Cephalopoda 61.8%

Other 3.4%

Nematoda 2 Mollusca 34

"*,Crustacea 110 Fish 16 Other 11 Other Crustacea 29 Ovalipes ocellatus 7 Cancer irroratus 13 Crangon septemspinosa 17 Neomysis americana 44 Figure 36. Abundance (percent occurrence) of the major prey items in the diet of summer flounder collected during NEFSC bottom trawl surveys from 1973-1980 and 1981-1990, focusing on fish, crustaceans, and mollusks. The category "animal remains" refers to unidentifiable animal matter. Methods for sampling, processing, and analysis of samples differed between the time periods [see Reid et al. (1999) for details].

Page 85 1981-1990 (n = 469)

Animal Remains 6.7%

Crustacea 28.0°/0 Polychaeta 0.4%

Mollusca 11.2%

Ctenophora 0.2%

Butterfish 5.2%

Sand Lances 10.5%

Cods 3.8%

Anchovies 17.4%'

Other Families 13.2%

Unknown Fish 49.8%

Fish 53.5%

Other Mollusca 3.3%

Loligo sp. 40.0%

Unknown Cephalopoda 56.7%

Animal Remains 6.:

Mollusca 11.2%

Other Crustacea 16.0%

Amphipods 13.3%

Crabs 43.3%

Shrimps 27.3%

Fish Figure 36. cont'd.

Page 86 Georges Bank - Middle Atlantic 20 18 0.0.

C,,

0 16-14 12 10 8

6-I//

//

0 0

.4-'

C-)

C a)

L..

'.7 V

4 2 4-,-

1,960 1965 1970 1975 1980 1985 1990 1995

,+ 0 2000 Year

-Commercial landings (mt)

---

Spring survey index (kg)

_ Smoothed survey index (kg)

- Spawning stock biomass (mt)

Figure 37. Commercial landings, NEFSC survey indices, and stock biomass for summer flounder on Georges Bank and in the Mid-Atlantic region.

Page 87 76' 740 72' 700

68.

660 760 740 720 70' 680 660 Numbero Fish Number olfRsh 0-0 0-0 W

E S10-99 10-9 9 100-999

.0 100 999 42o.

C.

j q '

42 I

e*

/

v

/'

4.,...

CT-38*

3 80oý Summer Flounder--Adults (>28cm)

Summer Flounder--Adults (>28cm)

Fall (1974 - 1978)

Fall(1989-1993) 360 o y :i NEFSC Bottom Trawl Surveys 360 NEFSC Bottom Trawl Surveys Fish caught/station (excluding null stations):

Rsh caught/station (exciuding null stations):

z,0 Mean: 6 Min: 1 Max: 52 Mean: 4 MIn: 1 Max: 48 Length (cm):

Length (am):

Mean: 39 Min: 29 Max: 79 I

Mean: 37 Min; 29 Max: 70 76' 74° 720 700 680 660 76° 740 720 700 680 66' Number of Fish Number of Fish 1 0-9 9

• 10 99 10 -99 I

NH 100 -

99'9' y

10 999 1000-90000b 0090; 42'

_X1 "42o t

oo o.*_,... -'*

40o 40,oY>:

. 1 i

i~*

4 8*

38*

Summer Flounder-Aut)28m Srn (1989 1993)de

~ D.~

Spring (1974.-1978)

~

~

Summrin Flounder-Au (199 cm 36-NEFSC Bottam Trawl Surveys 3*NEFSC Bottam Trawl Surveys 4Fish caughtlstatlon (exciuding nulstations):.ihcuh/tlo exldn ulsain)

Mean: 5 Min: 1 Max: 153 JJ-Mean:

2 Min: 1 Max: 9 Length (cm):

Length:(m Mean: 41 Min: 29 Max: T7 Mean: 37 In: 29 Max: 72 34l--3401 I'

I.

J l

.J A

i L

Figure 38. Distribution and abundance of adult and juvenile summer flounder during a period of high abundance (1974-1978) and a period of low abundance (1989-1993) based on spring and fall NEFSC bottom trawl surveys [see Reid et al.

( 1999) for details].

Page 88 72o 700 Length (cm):

Mean: 24 Min: 14 Max: 28 34o0:

Length (cm):

Mean: 23 Min: 15 Max: 28 760 740 720 Number of Fish l

0 -

0 10 99 100.

999 NA 1000.9000 700 680 660 ME' ~

MA Cr i

~3/

Summer Flounder--Juveniles (-= 28 cm)

Spring (1974 - 1978)

NEFSC Bottom Trawl Surveys Fish caught/statlon (excluding null stations):

Mean: 7 Min: 1 Max: 76 Length (cm):

Mean: 22 Min: 10 Max: 28 j

340 i_ - 7._1....

Figure 38. cont'd.