ML072070622
| ML072070622 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 09/30/1999 |
| From: | Berrien P, Goldberg R, Dante Johnson, Morse W, Pereira J, Ziskowski J 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 | |
| References | |
| NMFS-NE-138 | |
| Download: ML072070622 (45) | |
Text
NOAA Technical Memorandum NMFS-NE-138 Essential Fish Habitat Source Document:
Winter Flounder, Pseudopleuronectes americanus, 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 Symposiu m on the Potential for Development of Aquaculture in Massachusetts: 15-17 February 1995, Chatham/Edgartown/Dartmouth, Massachusetts. By Carlos A. Castro and Scott J. Soares, comps. & eds. January 1996.
v + 26 p., I 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 l1 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., 11 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 1997.
v + 50 p., I fig., 40 tables. NTIS Access. No. PB99-169997.
114. U.S. Atlantic and Gulf of 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-l 12345.
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 onitis) 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 appl.
NTIS Access. No. PB2000-100809.
C 0
4 ASMOS
)"M 4N T Of C A
NOAA Technical Memorandum NMFS-NE-138 This series represents a secondary level of scientiffic 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:
Winter Flounder, Pseudopleuronectes americanus, Life History and Habitat Characteristics Jose J. Pereira1, Ronald Goldberg1, John J. Ziskowskil, Peter L. Berrien 2, Wallace W. Morse 2, and Donna L. Johnson 2 1National Marine Fisheries Serv., Mi/ford Lab., 212 Rogers Ave., Milford, CT 06460 2 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. 1991 a), mollusks (i.e.,
Turgeon e t al. 19 9 8 b), 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 8 d). 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 1998e).
'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.
hTurgeon,-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.
dRice, 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. Bull. (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 Management
- 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 Life History
.. 1 H abitat C haracteristics..........
5 G eo grap h ical D istrib utio n...............................................................................
10 Status of the Stocks......................................................
11
- Research Needs................................................................................................................
11 A c k n o w led g m en ts...................................................................................................................................................................................
12 R e fe re n ce s C ited....
12 Tables Table I. Summary of life history and habitat parameters for winter flounder, Pseudopleuronectes americanus..............................
18 Figures Figure 1. The winter flounder, Pseudopleuronectes americanus (Walbaum) (from Goode 1884)..................................................
21 Figure 2.
Abundance of the major prey items of winter flounder collected during NEFSC bottom trawl surveys........................
22 Figure 3.
Distribution and abundance of juvenile and adult winter flounder collected during NEFSC bottom trawl surveys.............. 24 Figure 4.
Distribution and abundance of juvenile and adult winter flounder in Massachusetts coastal waters...............................
26 Figure. 5.
Distribution and abundance of juvenile and adult winter flounder collected in the Hudson-Raritan estuary.................. 27 Figure 6.
Abundance of winter flounder eggs relative to water temperature and depth from NEFSC MARMAP surveys........
29 Figure 7.
Abundance of winter flounder larvae relative to water temperature depth from NEFSC MARMAP surveys..................... :.30 Figure 8.
Abundance of juveniles and adults relative to water temperature and depth based on NEFSC trawl surveys.................. 31 Figure 9.
Abundance of juveniles and adults relative to water temperature and depth based on Massachusetts surveys................ 32 Figure 10. Abundance of juveniles and adults relative to temperature, DO, depth, and salinity from Hudson-Raritan trawl surveys....33 Figure 11. Distribution and abundance of winter flounder from Newfoundland to Cape Hatteras from 1975-1994........................ 34 Figure 12. Distribution and abundance of winter flounder eggs collected during NEFSC MARMAP surveys................................
35 Figure 13. Distribution and abundance of winter flounder larvae collected during NEFSC MARMAP surveys.............................
37 Figure 14. Commercial landings and survey indices for winter flounder stocks...............................................................................
39
Page 1 INTRODUCTION The winter
- flounder, Pseudopleuronectes americanus, a'small-mouthed, right-eyed flounder (Figure 1), is a valuable commercial and recreational species. It is distributed along the northwest Atlantic coast as far north as Labrador (Kendall 1909; Backus 1957) and as far south as North Carolina and Georgia (Hildebrand and Schroeder 1928; Klein-MacPhee, in prep.). One of the more familiar fishes in the Gulf of Maine (Klein-MacPhee, in prep.),
winter flounder are common on Georges Bank and in shelf waters as far south as Chesapeake Bay and are ubiquitous in inshore areas from Massachusetts to New Jersey.
The species is managed as three separate stocks: the Gulf of Maine, southern New England and the Middle Atlantic, and Georges Bank (Brown and Gabriel 1998).
However, there have been questions as to whether the population on Georges Bank, where fish tend to grow larger and have different meristic characteristics and movement patterns than those residing inshore (Lux et al.
1970; Howe ahd Coates 1975; Pierce and Howe 1977), is in fact a separate species.
It has been concluded that many of these differences could be attributed to temperature (Lux et al. 1970).
Except for the Georges Bank population, adult winter flounder migrate inshore in the fall and early winter and spawn in late winter and early spring throughout most of their range (Perlmutter 1947; Bigelow and Schroeder 1953; Pearcy 1962; Dovel 1967; Scarlett 1991).
In northern waters, spawning occurs somewhat later:. April in Passamaquoddy. Bay (Tyler 1971 a) and May and June in Newfoundland (Kennedy and Steele 1971; Van Guelpen and Davis 1979).
After spawning, adults typically leave inshore areas although some remain inshore year-round.
This Essential Fish Habitat source document will focus on specific habitat requirements of the various life history stages of winter flounder as well as their historical and current geographical distributions.
LIFE HISTORY The life history of winter flounder has been well studied (see Howell et al. 1992) and only a brief outline will be given here. Howell et al. (1992) also includes an excellent review of diseases and effects of pollutants.
Further information on pollution effects is provided by Gould et al. (1994).
EGGS The eggs of winter flounder are demersal, adhesive, and stick together in clusters. They range in size from 0.74-0.85 mm in diameter.
Although Breder (1923) reported that winter flounder eggs develop a "small sphere similar to oil globules in pelagic ova" which disappears with further development, Martin and Drewry (1978) make no mention of this structure. It is possible that the structure reported by Breder (1923) was an artifact. Hatching occurs in 2 to 3 weeks, depending on temperature, and. at sizes as small as 2.4 mm in the northwest Atlantic (Fahay 1983) and up to 3.0-3.5 mm in the Gulf of Maine (Bigelow and Schroeder 1953).
LARVAE Larvae are initially planktonic but become increasingly bottom-oriented as metamorphosis approaches. Settlement occurs at 9-13 mm standard length (SL) (Pearcy 1962; Witting 1995). Metamorphosis, when the left eye migrates to the right side of the body and the larvae become "flounder-like", begins around 5 to 6 weeks after hatching, and is completed by the time the larvae are 8'9 mm in length at about 8 weeks after hatching (Bigelow and Schroeder 1953). Variation in age at metamorphosis is greater than for size (Chambers and Leggett 1987),
with age variation influenced by temperature (Laurence 1975; see also Able and Fahay 1998).
JUVENILES Off southern New England, newly metamorphosed young-of-the-year (YOY) winter flounder take up residence in shallow water where they may grow to about 100 mm within the first year (Bigelow and Schroeder 1953).
Growth rates in the Mystic River, Connecticut
-estuary averaged 0.28-0.35 mm per day in summer and fall with monthly mortality during the first year averaging 31% and total mortality during larval (and juvenile stages) reaching over 99% (Pearcy 1962).
Average density of settled juveniles in this system was higher than 1/m2 (Pearcy 1962).
Growth rates may be somewhat faster in more southern waters.(Chesapeake Bay) where fish up to 110-180 mm are collected in late winter. In a southern New Jersey system, growth ranged from 0.23-0.47 mm per day (Witting 1995). In this system, settlement appeared to be localized in a small cove, with very high densities (averages reaching as high as 4.1 individuals/mi2) (Witting 1995).
In several caging studies at other coastal New Jersey locations, growth rates ranged even higher (Sogard 1992, 0.95 mm per day; Phelan et al., in press, 0.68 mm per day) and settlement appeared more widespread (B.A.
Phelan, National Marine Fisheries Service, Highlands, NJ, unpublished data).
Although juveniles 'presumably overwinter in the estuary (Bigelow and Schroeder 1953),
large numbers are also found on the shelf (Phelan 1992) and outside southern New Jersey estuaries (Able and
Page 2 Hagan 1995; Able and Fahay 1998).
ADULTS Winter flounder may grow up to 58 cm total length (TL) and attain 15+ years of age. Growth varies among geographical areas, with slower growth in the north than in the south. Growth in the Gulf of Maine (k = 0.41, L-,
= 39.8 cm for males, k = 0.27, Lo = 49.0 cm for females) was somewhat lower than on Georges Bank (k = 0.37, L-
= 55.0 cm for males, k = 0.31, L- = 63.0 for females)
(see Mayo 1994).
REPRODUCTION Winter flounder spawn from winter through spring, with peak spawning occurring during February and March in Massachusetts Bay and south of Cape Cod and somewhat later along the coast of Maine continuing into May (Bigelow and Schroeder 1953).
Spawning occurs earlier (November to April) in the southern part of the range (Klein-MacPhee, in prep.). Major egg production occurs in New England waters before temperatures reach 3.3TC with an upper limit of about 4.4-5.6°C in the inner parts of the Gulf of Maine (Bigelow and Schroeder 1953).
Spawning can occur at depths of less than 5 m to more than 45 m on Georges Bank, and at salinities of 11 ppt inshore near Woods Hole to 31-33 ppt offshore.
Winter flounder maturity comparisons are complicated by the complex stock structure of this species (O'Brien et al. 1993). Based on the Northeast Fisheries Science Center (NEFSC) trawl surveys, the median length at maturity (L50) for male and female winter flounder from Georges Bank was 25.6 and 24.9 cm respectively; median age at maturity (A50) was 1.9 years for both males and females (O'Brien et al. 1993).
For inshore stocks north of Cape Cod, values of L50 were 29.7 cm for females and 27.6 cm for males; for stocks south of Cape Cod, L50 was 27.6 cm for females and 29.0 cm for males.
Median age at maturity was 3.5 years for females and 3.3 years for males north of Cape Cod; 3.0 years for females and 3.3 years for males south of the Cape (O'Brien et al.
1993).
Other studies report different values. In Long Island Sound, maturity occurred at 2 to 3 years and 20 to 25 cm (Perlmutter 1947); in Newfoundland, L50 was 25 cm for females, 21 cm for males, with ages for full maturity reaching 7 years for females and 6 years for males (Kennedy and Steele 1971) indicating that maturity was related to size, not age. However, Beacham (1982) found that maturity of fish from the Scotian Shelf and southern Gulf of St. Lawrence was highly variable from year to year. Burton and Idler (1984) found a 2 to 3 year cycle in oocyte maturation and large numbers of non-reproductive individuals in any given year.
Thus, interpretations of winter flounder maturity data should be treated cautiously (O'Brien et al. 1993).
Fecundity measurements indicate that in Newfoundland, 220-440 mm females produced from 99,000 to over 2 million eggs (Kennedy and Steele 1971);
in Rhode Island, 250-450 mm females produced from 93,000 to over 1.3 million eggs (Saila 1962); and in coastal Massachusetts, 300-450 mm females produced from 435,000 to over 3.3 million eggs (Topp 1968).
Recent laboratory studies have shown that when held at 4'C, winter flounder spawned over a two month period with females and males averaging 40 and 147 spawns, respectively (Stoner et al. 1999).
Spawning was concentrated between sunset and midnight, with the majority of spawning events involving more than one male, which potentially maximizes fertilization success.
FOOD HABITS Pearcy (1962) investigated the food habits of winter flounder. larvae from hatching through metamorphosis. A large percentage of the stomach contents were unidentifiable but
- nauplii, harpacticoids, calanoids, polychaetes, invertebrate eggs, and phytoplankton were all present.
Food item preference changed with larval size: smaller larvae (3-6 mm) ate more invertebrate eggs and nauplii while larger larvae (6-8 mm) preferred polychaetes and copepods. Plant material was found in larval stomachs but usually with other food items and was probably incidentally ingested (Pearcy 1962).
Pearcy (1962) found that copepods and harpacticoids were important foods for metamorphosing and recently metamorphosed winter flounder.
Amphipods and polychaetes gradually' become more important for both YOY and yearling flounder (Pearcy 1962).
Franz and Tanacredi (1992) found that the amphipod, Ampelisca abdita, made.up the majority of the diet of young flounder in Jamaica Bay, New York. Stehlik and Meise (in press) found clear ontogenetic patterns in diet, with calanoid copepods disappearing from the diet as fish grew > 50 mm TL and an increase in the number of taxa in diet with growth.
Winter flounder have been described as omnivorous or opportunistic feeders, consuming a wide variety of prey (see Figure 2). Polychaetes'and crustaceans (mostly amphipods) generally make up 'the bulk of the diet (Hacunda 1981; Macdonald 1983; Steimle et al. 1993; Martell and McClelland 1994; Carlson et al. 1997).
Linton (1921) examined the stomachs of 398 winter flounder ranging in size from 25-225 mm. Annelids and amphipods dominate the diet in almost all size classes (Linton 1921). Winter flounder may modify their diet based on availability of prey.
They feed on bivalves (Medcoff and MacPhail 1952; Macdonald and Green 1986; Stehlik and Meise, in press), capelin eggs (Kennedy and Steele 1971; Frank and Leggett 1983) and fish
Page 3 (Kennedy and Steele 1971).
Adult winter flounder are sight feeders, using their dorsal fins to raise their heads off the bottom with eye turrets extended for a better view (Olla et al. 1969). Prey are then taken in a 10 to 15 cm lunge. (Olla et al. 1969).
If no prey are spotted, the fish change location and resume the feeding posture. A fish might change location and direction four to five times a minute.
These movements involve a combination of swimming and "shambling" (Kruuk 1963; Macdonald 1983) or literally crawling across the bottom on the tips of the fin rays.
Fish were able to maintain this feeding posture in currents exceeding 20 cm/sec by pushing the edges of the fins into the substrate (Olla et al. 1969).
This same feeding method is used by young-of-the-year and juvenile flounder as well (J. Pereira, National Marine Fisheries
- Service, Milford, CT, unpublished observation).
Increases in turbidity or current speed could interfere with feeding success.
The importance of adequate light for feeding in flounder is demonstrated in a study by Able et al. (1999) and Duffy-Anderson and Able (1999). Young-of-the-year flounder held in cages underneath piers in the lower Hudson River lost weight when compared to fish caged in open areas between the piers.
One of the contributing factors could have been an inability to feed due to lack of light (Able et al. 1999; Duffy-Anderson and Able 1999).
Macdonald (1983) noted that flounder were more attracted to moving rather than stationary prey and reemphasized the flounder's dependence on sight for feeding.. Frame (1971) noted that the amount and duration of feeding behavior varied with light levels, being reduced on cloudy and winter days and increased on sunny, days. Van Guelpen and Davis (1979) found that winter flounder moved out of shallow water during storm events to avoid turbulence.
They noted that Gibson (1973) observed similar behavior in other flatfish species particularly for plaice, Pleuronectes platessa.
It is possible that the suspended sediment caused by turbulence interferes with feeding.
Field observations by'Olla et al. (1969) show that adult winter flounder are inactive at night.
Stomach samples taken from fish during the day almost always contained food while those taken before sunrise were almost always empty indicating that adult flounder do not feed at night (Olla et al. 1969).
However, fish in the laboratory were nocturnal during the reproductive season, only becoming active during the day during the post-spawning periods under increasing temperature and photoperiod (Stoner et al. 1999).
Young-of-the-year winter flounder are also more nocturnal during the summer (Manderson et al., in review; B.A. Phelan, National Marine Fisheries
- Service, Highlands, NJ, unpublished observation).
Winter flounder have been reported to cease feeding during the winter months (Kennedy and Steele 1971; Van Guelpen and Davis 1979; Martell and McClelland 1994).
Other authors simply report a reduction in feeding in the winter (Frame 1971; Levings 1974). Recent field studies in a New Jersey estuary before, during and after the spawning season indicated that females began feeding, primarily on siphons of the clam, Mya arenaria, and ampeliscid amphipods earlier than males (Stoner et al.
1999).
In the laboratory, males fed only after most spawning had ended (Stoner et al. 1999).
Degradation or improvement of environmental conditions causing shifts in benthic invertebrate populations may also cause shifts in prey selection such as eating 'the pollution-tolerant annelid Capitella (Haedrich and Haedrich 1974; Steimle et al. 1993) or eating the pollution-sensitive amphipod, Unciola irrorata, once environmental conditions have improved (Steimle et al. 1993).
PREDATION Pearcy (1962) reported that the small medusae, Sarsia tubulosa, prey upon winter flounder larvae, and that all other potential predators of larvae were numerically unimportant when compared to Sarsia medusae.
The predatory
- amphipod, Calliopius laeviusculus, was shown to prey upon larval, winter flounder in the laboratory (Williams and Brown 1992).
Klein-MacPhee et al. (1993) suggests the mud anemone, Ceriantheopsis americana, as a potential predator on winter flounder larvae. Pepin et al. (1987) reported that Atlantic mackerel, Scomber scombrus, selectively prey-on larval fish between 3 and 10 mnm in length. Mackerel would co-occur with winter flounder larvae in early spring.
Since winter flounder are 3.5 mm in length at hatch they are 'certainly vulnerable to predation by mackerel.
Howe et al. (1976) found that injured juvenile winter flounder were more common when large numbers of "snapper" bluefish, Pomatomus saltatrix, were present in their study area, suggesting that young bluefish are an important predator on young winter flounder. Gulls and cormorants were also suggested as important predators (Howe et al. 1976).
Witting and Able (1995) have documented in the laboratory the ability of the sevenspine bay shrimp, Crangon septemspinosa, to prey on YOY winter flounder ranging in length from newly settled, 10 mm individuals to those up to 20 mm long.
Juvenile winter flounder, particularly as they get larger, are probably also preyed upon by the same predators that prey on adults. Summer flounder, Paralicthys dentatus, sea robins (Prionotus evolans),
and windowpane (Scophthalmus aquosus) also prey on YOY and juvenile winter flounder (Poole 1964; Richards et al. 1979; Manderson et al. 1999, in review). As many as 12 winter flounder have been found in a single searobin stomach (P.E. Clark, National Marine Fisheries Service, Milford, CT, unpublished observation).
Page 4 Adult winter flounder are preyed upon by a wide variety of predators including striped bass (Morone saxatilis), bluefish, spiny dogfish (Squalus acanthias),
goosefish (Lophius americanus), oyster toadfish (Opsanus tau), and sea raven (Hemitripterus americanus), (Lux and Mahoney 1972; Azarovitz 1982).
Cormorants, blue herons, seals, and ospreys have also been cited as predators (Pearcy 1962; Tyler 1971b). Payne and Seizer (1989) found that seals ate 5 different species of flounder including winter flounder, but that the flounder group as a whole made up only 10 % of the diet.
MIGRATION With the exception of the Georges Bank population, adult winter flounder migrate inshore in the fall and early winter and spawn in late winter and early spring.
Following spawning, adults typically leave inshore areas when water temperatures exceed 15'C (McCracken 1963; Howe and Coates 1975); however, these movements may not be totally controlled by temperature. Winter flounder may remain inshore year-round if temperatures remain at 15'C or lower and if enough food is available (Kennedy and Steele 1971).
In the more northern latitudes, they may be driven out by turbulence or ice formation (Van Guelpen and Davis 1979).
Powell (1989) reviewed tagging studies of winter flounder conducted by Perlmutter (1947), Saila (1961, 1962), McCracken (1963),
Poole (1969),
Howe and Coates (1975), Van Guelpen and Davis (1979), Danila and Kennish (1982), Scarlett (1983), Weber and Zawacki (1983), Northeast Utilities Service Company (1984), and Weber (1984), and compared them to his own studies in Rhode Island. He concluded that, with the exception of Georges Bank, there were two distinctive patterns of movement.
While all studies showed a
winter congregation on inshore, shoal spawning grounds and summer dispersal to deeper cooler waters, the extent and the timing of these movements varied with location.
Winter flounder distributions in NEFSC bottom trawl surveys (Figure 3), Massachusetts inshore trawl surveys (Figure 4), and Hudson-Raritan trawl surveys (Figure 5) confirm this general pattern of movement.
Howe and Coates (1975) tagged fish during the winter and early spring while they were concentrated near spawning grounds in areas both north and south of Cape Cod and on Georges Bank.
Fish tagged north of Cape Cod tended to make shorter post-spawn migrations (average distance traveled from tagging location = 14.3 km or less) probably because of the close proximity of cooler bottom temperatures (Howe and Coates 1975).
Studies conducted even further to the north in Nova Scotia (McCracken 1963) and Newfoundland (Van Guelpen and Davis 1979) also showed short onshore-offshore migrations associated with spawning. Most fish tagged on Georges Bank tended to stay on the Bank and there was very little exchange (less than 1% in either direction) with fish on Nantucket Shoals (Howe and Coates 1975). Fish tagged south of Cape Cod migrated farther than their counterparts north of the Cape (average distance traveled up to 61.2 km). Mixing was minimal; only nine fish (0.66% of the tag recoveries) tagged north of the Cape were recovered south and east of the peninsula and only 61 fish (2.50% of recovered tags) tagged 'south of Cape Cod were recaptured to the north.
Tag returns in the fall showed return of fish to inshore, shoal areas when water temperatures had reached 15"C (Howe and Coates 1975).
Studies conducted further south in Connecticut (Northeast Utilities Service Company 1984), New York (Poole 1969; Weber and Zawacki 1983; Weber 1984),
and New Jersey (Danila and Kennish 1982; Scarlett 1983) also showed longer onshore-offshore migrations. Powell (1989) also noted that in the tagging studies south of Cape Cod, all post-spawn, summer migrations were to the east, i.e., offshore. This adult migration is shown by seasonal trawl survey catches, especially off New Jersey and southern New England (Figures 3 and 4) as well as by more recent studies. For example, Pereira et al. (1994) found that some fish move as far as 113 km to the east during the post-spawn period. Phelan (1992) tagged fish in the New York Bight area and recovered one fish from Nantucket, a distance of 328 km from the tagging site.
Timing of these spawning and post-spawning movements varied along the coast, occurring earlier farther south and later farther north.
There are exceptions to these general patterns, and migrations may also be related to food availaility.
Kennedy and Steele (1971) reported that winter flounder left Long Pond, Canada and were found in Conception Bay, Canada even though water temperatures in both locations were around I ITC. They attribute the exodus to a lack of food in Long Pond.
Van Guelpen and Davis (1979) reported emigration from the study area in July even though water temperatures remained within the winter flounder's acceptable range. They believe this was a feeding migration similar to that reported by Kennedy and Steele (1971).
When winter flounder disappeared from study areas again in August, they were found in nearby Horse Cove where they had been feeding heavily on capelin eggs (Van Guelpen and Davis 1979). Feeding migrations by winter flounder have also been documented by Tyler (1971b) who found that adult winter flounder move into the intertidal zone on the high tide to feed. It would seem that if water temperatures are not limiting over a wide area, winter flounder will move in response to availability of food. Howe and Coates (1975), who noted similar movements in the Cape Cod area, doubt that these movements are solely in response to availability of food.
Howe et al. 1976 and studies in Raritan Bay (Figure 5) provide evidence that some adult fish may remain inshore throughout the summer.
Page 5 STOCK STRUCTURE I This species is currently managed as three stocks (one north of Cape Cod, one south of the Cape and the third on Georges Bank) which were first differentiated based on differences in fin ray counts and movement patterns (Lux et al. 1970; Howe and Coates 1975; Pierce and Howe 1977).
The Georges Bank stock not only differed in fin ray count, but has a much higher growth rate (Lux 1973). Some researchers feel that three "stock complexes" are being managed and that there may be one or more stocks in Canadian waters, based on differences in age at maturity (Kennedy and Steele 1971) and migratory habits (Van Guelpen and Davis 1979). Other stocks may exist north of the Massachusetts border along the coast of New Hampshire and Maine.
HABITAT CHARACTERISTICS A summary of the habitat characteristics of the various life history stages of winter flounder is provided in Table I.
EGGS Collection of winter flounder eggs from the wild is difficult because of their adhesive and demersal nature. It is these same characteristics, however, that make them valuable in pinpointing spawning grounds. With the exception of Georges Bank and Nantucket Shoals, winter flounder eggs are generally collected from very shallow waters (less than about 5. m), at water temperatures of 10'C or less, and salinities ranging from 10 to 30 ppt.
These shallow water, nearshore habitats are of critical importance because they are most likely to be impacted by human activities. The type of substrate where eggs are found varies, having been reported as sand, muddy sand, mud and gravel, although sand seems to be the most common.
Vegetation may or may not be a factor.
Spawning areas also occur where hydrodynamics function to keep the hatched larvae from being dispersed (Pearcy 1962; Crawford and Carey 1985; Monteleone 1992). This is true even on Georges Bank where different water masses function to keep larvae on the Bank (Backus and Bourne 1987).
Scott (1929) collected winter flounder eggs near St.
Andrews, New Brunswick, with a plankton net in one foot of water along the flats on mud bottom.
Surface temperatures in the area ranged from 9.25-10.0'C, but bottom temperatures to which the-eggs were exposed were probably lower.
Pearcy (1962) working in the Mystic
- River, Connecticut, began his sampling in February when water temperatures were around 2-50C.
Specific gravity of seawater where eggs were collected was reported to be 1.01-1.024 (corresponding roughly to a salinity range of 10 to 25 ppt) at 50C.
Crawford and Carey (1985) collected winter flounder eggs using a benthic sled in Point Judith Pond, Rhode Island.
The greatest concentration of eggs was found in the vicinity of a tidally submerged gravel bar with eggs clumped on the gravel substrate or attached to fronds of algae. Crawford and Carey (1985) began their sampling only after water temperatures had reached 3'C. It'has also been reported that winter flounder eggs collected by divers were attached to vegetation (Anonymous 1972).
Scarlett and Allen (1989) found that winter flounder eggs constituted the vast majority of all the eggs found in collections made in the Manasquan River in New Jersey in February and March of 1985.
Eggs were found at salinities ranging from 14 to 32 ppt, temperatures of 0.9 to 10"C, and depths of 2-4.5 m. In a subsequent study, Scarlett (1991) used an epibenthic sled for sampling winter flounder eggs in the Shrewsbury and Navesink rivers in New Jersey to identify spawning areas. He collected eggs in water temperatures ranging from 4 to 7.5'C, at salinities of 14 to 22 ppt, and at depths of 2 to 4 m.
More recently, Monteleone (1992) collected winter flounder eggs in a plankton net towed horizontally just under the surface of the water in a relatively shallow (average depth 1.3 m).
The turbulence caused by the sampling gear was probably responsible for these demersal eggs finding their way into the net. Like Scott (1929),
Monteleone (1992) reported a surface water temperature of 9.1°C during the collection of winter flounder eggs.
Hughes (in prep.) used a benthic sled to collect winter flounder eggs in Point Judith and Ninigret coastal salt ponds in Rhode Island in 'the vicinity of the North Cape oil spill. Samples were taken in March. Depths in the sample areas ranged from I to 3 m. Lee et al. (1997) measured temperature and salinity near Hughes (in prep.)
sample sites at various times between 1985 and 1994.
Samples taken in March of various years showed a mean temperature of 6+/-1.94°C and a mean salinity of 23+/-8.01 ppt.
Temperature and depth measurements taken in conjunction with the plankton samplings conducted by the NEFSC Marine Resources Monitoring, Assessment and Prediction (MARMAP) program on Georges Bank showed that the eggs were collected at water temperatures between 3 and 8TC and at depths of 90 m or less (Figure 6). These results confirmed the report by Bigelow and Schroeder (1953) that winter flounder spawn on sandy bottom, often in water as shallow as one to three fathoms but as deep as 25 to 40 fathoms (13-22 m) on Georges Bank and, most probably, on Nantucket Shoals.
While evidence from eggs collected in the field provides information about the conditions under which winter flounder prefer to spawn, laboratory studies provide information about how winter flounder eggs might fare in marginal environments.
One parameter
Page 6 typically studied in the laboratory is the number of days.
required for hatching.
Time to hatch is 'controlled by temperature.
Human activities could change ambient temperatures directly by discharge of heated cooling water or indirectly by changing the hydrodynamics and therefore, the water turnover rate of an area.
Scott (1929) collected winter flounder eggs in the field, and in the laboratory determined the number of days for all the eggs to hatch or die, as well as hatching success.
He found that 4-5'C produced the best. hatch success, averaging 73%.
The average time for all the eggs to hatch or die was 26 days. At 0°C, only 50% of the eggs had hatched or died in an average of 21 days and the hatch success was poor, averaging only about 9%.
Williams (1975) reported an average'of 38.6 days to hatch or die for eggs held at 0°C. Williams (1975) also reported an average hatch time of 21.5 days for eggs held at,3.5°C, very close to the value reported by Scott (1929) for eggs held at 4-5'C. Eggsheld at 12 to 17TC hatched sooner (mean 1 8 days), but the percent hatch only averaged about 52%. An earlier, similar study by Brice (1898) found that eggs hatched in 17-18 days at 3°C. Neither Brice (1898) nor Scott (1929) determined the developmental stage of the field-collected embryos when they were brought into the laboratory or what percent were even fertilized. This may explain some of the variability apparent in the reported time to hatch in these studies.
Rogers (1976) tested the effects of various combinations of temperature (3-15,"C) and salinity (0.5 to 45 ppt) on the viability and incubation times of winter flounder embryos and she concluded that winter flounder embryos are euryhaline and hatch at salinities of 5 to 40 ppt.
Salinity extremes tended to induce abnormal development, however, and the best survival occurred between 10 and 30 ppt.
She concluded that optimal conditions for winter flounder embryo development and survival appear to be 15 to 35 ppt salinity at 3TC and 15 to 25 ppt for temperatures above 3°C. These results agree well With the results of Williams (1975), who reported a minimum mortality range of 0 to 10°C and an upper lethal limit of 150C.
Rogers (1976) also found that incubation times (days for 50% of the embryos to hatch) were inversely related to temperature: 19 to 31 days at 3TC and 10 ppt salinity, and 5 to 10 days at 14TC, regardless of salinity tested.
Buckley (1982) also reported similar results, noting that the time required for 50% hatch of embryos held in the laboratory was 8 days at I0°C and 23 days at 2'C.
Increased mortality was noted in developing embryos held at 2'C. These results agreed more closely with the statements of Bigelow and Schroeder (1953), who report that hatching occurred in 12-15 days at a temperature of 2.8 to 3.3"C.
This inverse relationship between incubation time and temperature -may provide a mechanism for the phenomenon observed by Frank and Leggett (1983).
They found that several species of fish which laid demersal eggs (capelin, sea snail, radiated shanny, and winter flounder) seemed to time their hatching to the advent of favorable environmental conditions. Hatching occurs simultaneous to the onset of onshore winds which cause the replacement of cooler, predator-laden, food-poor, up-welling waters with warmer, predator-poor, food-rich, surface water over the shallow spawning areas.
The synchronous hatching is thought to have the effect of swamping predators and enhancing survival of winter flounder because the capelin are so much more numerous than the other species.
Crawford and Carey (1985) described a similar phenomenon when they reported that a mid-February pulse of warm weather seemed to stimulate winter flounder spawning in Point Judith Pond, Rhode Island.
LARVAE Pearcy (1962) concluded that because winter flounder spawn in coves and inlets and the young stages are non-dispersive, breeding and nursery grounds would be close together.
This view had been previously expressed byPerlmutter (1947). Thus, larvae (and later
.juveniles) may offer an important clue to the location of spawning grounds, and are the link between spawning grounds, and nursery areas.
Data from the NEFSC MARMAP ichthyoplankton surveys show that, with the exception of Georges Bank and Nantucket Shoals, most winter flounder larvae are found inshore and that spawning progresses from the southern end of its range northward (see Geographical Distribution below).
Pearcy (1962) collected winter flounder larvae from the Mystic River, Connecticut. Comparing the number of larvae in surface tows to those collected by bottom tows he found that the bottom tows contained the majority of the larvae.
He also knew from laboratory observations that winter flounder larvae are negatively buoyant and sink when they stop swimming. His hydrographic survey of the estuary revealed that in the surface waters the net movement over a tidal cycle was seaward while in the bottom waters it was landward. The natural tendency of the larvae to sink would explain why most were caught near the bottom and would also function to retain the larvae within the estuary rather than get washed out in the surface waters. In fact, he calculated that only about 3%
of the larval population was dispersed seaward per tidal cycle.
Crawford and Carey (1985) believe that spawning areas and nursery areas are close together, after locating both eggs and larvae in Point Judith Pond in Rhode Island. They concluded that winter flounder larvae could have been retained in the estuary by the mechanism proposed by Pearcy (1962) but that the hydrodynamics of the area also played a role. They further suggested that winter flounder, when they spawn, take advantage of the hydrodynamic characteristics of small, narrow estuaries
Page 7 that restrict water flow in order to help retain the larvae in suitable nursery areas.
Monteleone (1992) noted the highest concentrations of winter flounder larvae in Great South Bay, New York at stations with low current speeds and turnover rates.
Winter flounder larvae were collected in the higher salinity regions of Miramichi Bay (New Brunswick, Canada) in early to mid-June where bottom salinities ranged from 6 to 26 ppt, and temperatures ranged from 12.5 to 20.5°C (Locke and Courtenay 1995).
Scarlett (1991) collected winter flounder larvae in the Navesink and Shrewsbury Rivers in New Jersey from February through April where bottom salinities ranged from 10 to 22 ppt, bottom temperatures ranged from 2 to 19.5'C and depths ranged from 2 to 6 m. Pearcy (1962) found that winter flounder larvae were common in the upper Mystic River Estuary from May to June when temperatures ranged from 3 to 15'C. Average bottom salinities for the upper estuary ranged from 18 to 22 ppt.
Scarlett and Allen (1989) collected winter flounder larvae in the Manasquan River in New Jersey at salinities ranging from 4 to 30 ppt and temperatures ranging from 0.9 to 15C.
NEFSC MARMAP surveys collected larvae from March through July, and in September (Figure 7).
Most were caught at temperatures of 6-10'C (those caught in September were at 18°C) and depths of 10-70 m.
Winter flounder larvae are surprisingly tolerant of short-term temperature shock.
In laboratory studies, Itzkowitz and Schubel (1983) found that mortality in five-day-old winter flounder larvae was minimal when the temperature was increased from the acclimation temperature of 5 to 27'C (a change in temperature of 22"C) so long as the duration was kept to less than 32 minutes. At longer durations, mortality increased rapidly.
Similar results were obtained for changes in temperature of 24°C if duration was 16 minutes or less. At changes in temperature > 28"C mortality was virtually total and immediate (Itzkowitz and Schubel 1983).
YOUNG-OF-THE-YEAR, YEARLINGS AND JUVENILES Winter flounder less than one year old (or young-of-the-year, YOY) are treated separately here because their habitat requirements are so different from that of the larger juveniles (fish I year old or more). Yearling is a term used for fish which are between one and two years of age; their behavior being transitional between YOY and older juveniles.
Winter flounder spend their first year in very shallow inshore waters. Although temperature tolerance of YOY is higher than for yearlings or adults, Pearcy (1962) concluded that temperatures of 30'C might be too high.
He found that an area that had produced fish previously failed to do so when the temperature reached 30"C, but that the fish returned when temperatures were lower. This upper limit is in agreement with studies by Huntsman and Sparks (1924) and Battle (1926) who also noted higher lethal temperatures for smaller flounder than for larger ones, and with McCracken (1963) who determined an upper incipient lethal temperature of 27'C. Pearcy (1962) reported a minimum lethal temperature between -1.5 and -
1.0IC. Juvenile winter flounder captured in offshore areas by NEFSC bottom trawl surveys were found at temperatures well outside of these lethal limits.
The majority of juveniles were at 4-70C in the spring and 11-15'C in autumn (Figure 8).
Laboratory studies by Casterlin and Reynolds (1982) on yearling flounder indicated that flounder selected temperatures in the range of 8-27'C, with a mode of 18.5IC. They also noted that in the laboratory, these fish were more active at night.
Young-of-the-year flounder also tolerate lower salinities (5 ppt) than do yearling flounder (10 ppt)
(Reynolds and Thomson 1974). Pearcy (1962) reported that the minimum salinity tolerance varied between I and 5 ppt for flounder as small as 7-10 mm. Bigelow and Schroeder (1953) reported that winter flounder are commonly found in salinities ranging from 35 ppt to water that was fresh enough to drink.
They were probably including all life history stages in that statement.
Ziskowski et al. (1991) investigated low dissolved oxygen tolerance and behavior of yearling winter flounder in the laboratory. Mortality occurred when flounder were exposed to 1.1 to 1.5 mg/I dissolved oxygen. Flounder were able to withstand an 8-hr exposure to dissolved oxygen levels in the 1.2 to 1.4 mg/I range. Low oxygen tolerance is not without a price, however.
Bejda et al.
(1992) found that growth of juvenile winter flounder was significantly reduced when dissolved oxygen levels were maintained at 2.2 mg/I or varied diurnally between 2.5 and 6.4 mg/I for periods of up to 11 weeks.
Pearcy (1962) conducted tag-recapture studies that indicate a relatively stable population of juvenile winter flounder within the Mystic River estuary over the summer and much lower numbers of juveniles beyond the mouth.
Other investigations confirm that YOY winter flounder remain in the nearshore zone and migrate very little during their first summer (McCracken 1963; Saucerman 1990; Saucerman and Deegan 1991). In winter however, Pearcy (1962) found that catches increased outside of the estuary while densities within the estuary dropped, implying an outward winter migration. Warfel and Merriman (1944) made similar observations.
Richards (1963) found increased numbers of juveniles in offshore locations in the winter.
Laboratory experiments by McCracken (1963) and Pearcy (1962) showed that YOY winter flounder were less photonegative, than yearling flounder. Pearcy (1962) further showed that YOY winter flounder became more photonegative in the winter. Thus it seems that photoresponse and temperature preferences drive the YOY flounder from the shallows in the late fall and early winter of their first year and keep older
Page 8 juveniles in deeper, cooler water much of the year.
Several investigators have reported that the highest densities of newly settled winter flounder are found on muddy substrates (Saucerman 1990; Howell and Molnar 1995; O'Connor 1997; Phelan et al.,
in prep.).
Paradoxically, Saucerman (1990) also found that growth rates were slowest in these areas.
She attributed this difference to increased competition for food caused by the high density of fish and possibly the detrimental effects of low oxygen levels later in the summer. Both Saucerman (1990) and O'Connor (1997) felt that smaller juveniles prefer finer sediments to bury into as was suggested by Gibson and Robb (1992) for the European flounder, Pleuronectes platessa. In laboratory experiments, young-of-the-year winter flounder < 40 mm SL consistently preferred fine-grained sediments (Phelan et al., in prep.).
Since winter flounder metamorphose at a smaller size than other flatfishes (Bigelow and Schroeder 1953), it seems unlikely that a newly metamorphosed, 8 to 9 mm long flounder actively seeks out these soft muddy areas.
It is more likely that they are simply deposited there by currents.
Howell and Molnar (1995) reported that the highest catches of YOY winter flounder occurred on muddy substrates or muddy substrates covered by leaf litter or bivalve beds.
Witting (1995) and Able and Fahay (1998) have shown that specific areas, i.e., small coves inside Little Egg Inlet in New Jersey, by virtue of location, proximity to currents or other factors, may serve as critical habitat, supporting high densities of recently settled individuals.
What these areas have in common is that they are depositional areas probably with low current speeds. We have already seen that spawning winter flounder take advantage of areas of appropriate hydrodynamics and current speeds to insure that larvae are retained in the nursery areas. Perlmutter (1947) and Pearcy (1962) both concluded that because eggs and larvae are non-dispersive that the nursery grounds will be close to the spawning grounds. In a sense, it is the spawning adults that choose the habitat for YOY winter flounder. Recent studies by Pereira et al. (1994) and Curran et al. (1996) support this idea.
Sogard and Able (1991) and Sogard (1992) found that YOY-winter flounder in Great Bay-Little Egg Harbor in New Jersey were more abundant on unvegetated substrates.
Their ability to bury in the sediment and change color to match it frees them from dependence on vegetation for refuge from predators. In this system, Able and Fahay.(1998) indicate that juveniles larger than 25 mm are found in a variety of habitats types, regardless of sediment and structure.
These habitats include macroalgae (Able et al. 1989), marsh creeks (Rountree and Able 1992) and to a lesser extent eelgrass (Goldberg et al., in prep.). Recent comparisons of habitat-specific patterns of abundance and distribution of YOY winter flounder in this system, as well in the Hudson-Raritan estuary and Long Island Sound, support the conclusion that habitat utilization by YOY winter flounder is not consistent across habitat types and is highly variable among systems and from year to year (Goldberg et al., in prep.).
The shallow inshore areas where YOY flounder spend their first 5 or 6 months of life are susceptible to anthropogenic impacts.
Briggs and O'Connor (1971) compared the abundance of 40 different species of fish collected from undisturbed areas with natural vegetation with those collected where dredge spoil material (mostly sand) had been deposited.
Species diversity was consistently higher over the undisturbed bottoms. Most
- species, including winter
- flounder, preferred the undisturbed bottom.
There have been a few attempts to relate juvenile habitat area to winter flounder production.
Saila et al.
(1965) calculated the theoretical biomass of juveniles needed to support the adult fishery. His studies led him to conclude that about 30% of the equilibrium yield weight is present in juveniles at 5 months of age and that efforts to enhance the fishery would be better aimed at culture and release of juveniles rather than larvae (Saila et al.
1965).
Howe et al. (1976) used tagging methodologies to investigate the contribution of the Waquoit Bay-Eel Pond spawning/nursery areas to the offshore trawl fishery. This fishery includes NMFS statistical subareas number 538 (southern Massachusetts),
521 (west side of South Channel), and 526 (Nantucket Shoals and Lightship Grounds).
By accounting for natural mortality and calculating the number of new recruits emigrating from these nursery areas and becoming available to the offshore fishery, they were able to calculate that Waquoit Bay-Eel Pond contributed 0.16% of the recruitment required to maintain an equilibrium catch.
ADULTS Laboratory - experiments by Reynolds (1977) established a preferred habitat temperature for adult winter flounder of 13.5'C. This concurs with the findings of McCracken (1963) who concluded, based on a review of field studies of winter flounder distribution and water temperatures, that adults have a preferred temperature range of 12-15 0C.
Results from several experimental trawl surveys tend to agree with these results. NEFSC trawl surveys captured adults at temperatures of 4-6"C in spring and 10-150C in the fall (Figure 8). In the inshore waters of Massachusetts, adults were captured at 5-13'C in spring and 9-13'C in the fall (Figure 9).
In the Hudson-Raritan estuary, most adults were captured at 4-12TC (Figure 10).
In contrast, Olla et al. (1969) observed actively feeding winter flounder where bottom temperatures always exceeded 17.2'C. They found active feeding at temperatures up to 22.2°C; but at 23°C feeding ceased and
Page 9 the flounder buried themselves in the substrate, where temperatures 5 or 6 cm below the surface of the sediment were 19.8 to 20°.C. They concluded that winter flounder escape short-term thermal stress by burying in the cooler sediments.
Although this research seems to be at odds with the findings of McCracken (1963) and Reynolds (1977), Olla et al. (1969) did not report the size of the flounder they observed at these high temperatures.
In another part of the study these authors reported stomach contents of fish ranging in size from 15 to 36 cm. If the fish observed during the high temperature period were toward the smaller end of the range reported for the feeding portion of their study (i.e., closer to the 15 cm end of the range of fish studied), that would likely make them yearlings.
Reynolds (1977) determined that yearlings prefer a temperature of 18.5"C and may be able to tolerate these higher temperatures. Larger fish may have left the area because many have a lower temperature tolerance than smaller fish (McCracken 1963).
Acclimation is another important factor in determining temperature tolerance.
Laboratory manipulation of acclimation temperature from 4 to 230C increased the critical thermal maximum from 26 to 32'C (Everich and Gonzdlez 1977). If the temperature increase was gradual enough, acclimation could have occurred in the fish studied by Olla et al. (1969), thereby resulting in a higher temperature tolerance.
Pgarcy (1962) reported that catches of adults in the upper estuary of the Mystic River, Connecticut, increased in February, peaked in March, and continued to be relatively high into April.
Bottom temperatures during this period range from 1-10 TC.
He reported that peak spawning occurred when temperatures were between 2 and 5T. Kennedy and Steele (1971) reported that peak spawning of winter flounder in Long Pond, Conception Bay, Canada occurred in 'May and early June.
Water temperatures in May when the bulk of the spawning occurred were 8°C (Kennedy and Steele 1971).
Van Guelpen and Davis (1979) reported that peak spawning in Conception Bay occurred in June in 1979 when water temperatures were 6'C.
McCracken (1963) found that winter flounder survived in salinities as low as 15 ppt, confirming earlier work done by Sumner (1907).
Although Bigelow and Schroeder (1953) reported that winter flounder commonly live in areas where salinities are so low that the water was fresh enough to drink to areas where salinity was 35 ppt, McCracken (1963) found that winter flounder died in 72 to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> when exposed to salinities of 8 ppt.
It is difficult to assess the significance of these studies by McCracken (1963) since he did not always make it clear what size fish he used in these experiments. Bigelow and Schroeder (1953) probably are including all age groups in the salinity range that they cite and salinity tolerance is known to be age dependent.
Adults captured in the Hudson-Raritan estuary were found at salinities as low as 15 ppt, although most were found at > 22 ppt (Figure 10).
Since adult winter flounder prefer to live in cooler waters, they do not often encounter low oxygen events.
However, these do occur from time to time in response to high nutrient loading.
Howell and Simpson (1994) described the distribution and abundance of finfish and lobsters in Long Island Sound in relation to near-bottom.
dissolved oxygen levels. Winter flounder abundance was significantly lower when dissolved oxygen was below 2.0 to 2.9 mg/l.
Also significant was the decline in mean length of winter flounder as dissolved oxygen levels declined.
Since the catch included fish ranging in size from 7 to 35 cm, it is probable that the decline in size of fish results from larger fish leaving the area before smaller fish which are more tolerant of low dissolved oxygen 'conditions (see above).
Howell and Simpson (1994) also raised the possibility that the mean length difference was caused by slower growth rates caused by low dissolved oxygen (Bejda et al. 1992). This may be possible if low oxygen events are of long duration or periodic in nature.
With the exception of Georges Bank and Nantucket Shoals (see Figure 3), mature winter flounder are found in very shallow waters during the spawning season.
Bigelow and. Schroeder (1953) reported that winter flounder spawn on sandy bottom, often in water as shoal as one to three fathoms but as deep as 25 to 40 fathoms on Georges Bank. Kennedy and Steele (1971), working in Conception Bay, Newfoundland found that winter flounder spawn in May and June on sandy bottoms at depths less than 6 m. McCracken (1963) reported that spawning in Passamaquoddy Bay, New Brunswick occurred at depths of 0 to 9 m. Pearcy (1962) reported that winter flounder spawn in the Mystic
- River, Connecticut at depths of 5 m or less.
After spawning, adults may remain in the spawning areas before moving to deeper waters when water temperatures reach 15'C (McCracken 1963).
Kennedy and Steele (1971) found them at depths of 7-10 m in the post-spawning period.
McCracken (1963) found that winter flounder remained in Passamaquoddy Bay after spawning, but in deeper water (around 20 m).
Trawl surveys conducted by NEFSC show the bulk of the adult catch occurred in water 25 m or less in the spring (during and just after spawning) and 25 m or deeper in the fall (prior to spawning) (Figure 8). The Massachusetts survey shows similar results (Figure 9).
Post-spawning migrations of winter flounder along the New Jersey coast appear to be limited by the 40 m contour (Danila and Kennish 1982; Scarlett 1983).
Migration of flounder from shoal areas south and east of Cape Cod appears to be limited by the 55 m contour (Howe and Coates 1975).
Laboratory experiments by McCracken (1963) demonstrated that adult winter flounder are less sensitive to light than YOY and juvenile winter flounder. Small flounder (6-9 cm) tended to be photophilic while intermediate fish (12-18 cm) were photophobic.
Large fish (28-33 cm) responded negatively to bright lights but
Page 10 not to lower levels of illumination.
Casterlin and Reynolds (1982) showed that the locomotor activity patterns of sixteen 12 to 13 cm flounder they examined in the laboratory were decidedly nocturnal.
The spatial distribution of flounder observed in the field (YOY in the nearshore zone, older juveniles further offshore) may in part be due to these differences.
GEOGRAPHICAL DISTRIBUTION Winter flounder are distributed from the Strait of Belle Isle, off northwest Newfoundland, to Cape Charles, Virginia (Figure I1). The area of highest abundance is the Gulf of St. Lawrence, off New Brunswick and northern Nova Scotia.
EGGS AND LARVAE The geographical distribution of winter flounder eggs and larvae matches that reported for the adults. Eggs and larvae have been collected from Canadian waters (Scott 1929; Locke and Courtenay 1995) to Chesapeake Bay (Dovel 1967). Govoni (1973) studied the icthyoplankton communities of the Acushnet and Westport Rivers in Massachusetts and found winter flounder larvae in his collections. Collection of winter flounder eggs in benthic sled samples show that coastal salt ponds in Rhode Island play host to much of the spawning activity in Rhode Island waters (Crawford and Carey 1985; Hughes, in prep.). The Pettaquamscut River and Narragansett Bay also support winter flounder spawning (Anonymous 1972; Bourne and Govoni 1988).
Collection of eggs and larvae by Pearcy (1962) and Monteleone (1992) confirm that the waters of Connecticut and Great South Bay, New York also serve as spawning areas for winter flounder. Winter flounder were the most common larva collected by Croker (1965) in the Sandy Hook estuary in New Jersey.
The Navesink, the Shrewsbury, (Scarlett 1991), and the Manasquan rivers (Scarlett and Allen 1989) in New Jersey all harbor winter flounder larvae during the spawning season.
Both the Indian River and Rehoboth Bay in Delaware also serve as spawning areas for winter flounder (Daiber et al. 1976).
Eggs and larvae of winter flounder have been reported from several areas (the Magothy and Patuxent Rivers and the upper bay near the Susquehanna River) at the northern end of Chesapeake Bay (Dovel 1967, 1971).
It seems unlikely, at first, to find winter flounder spawning so far south, in Chesapeake Bay.
- However, Chesapeake Bay runs almost north and south, and the Magothy River is located at the same latitude as the important spawning areas mentioned above in Delaware Bay, the Indian River and Rehoboth bays located a short distance to the east.
Winter flounder eggs and larvae have also been collected in standard plankton tows utilizing bongo nets by the NEFSC MARMAP survey (Figures 12 and 13). In some cases this was probably due to the nets accidentally hitting the bottom, but this explanation is not sufficient to explain the large numbers of eggs collected on Georges Bank and Nantucket Shoals. The large numbers of eggs collected on Georges Bank are probably due to the unique hydrodynamic conditions found there. The water mass on central Georges Bank is characterized by lack of stratification at any time of year due to good vertical mixing (Backus and Bourne 1987). These same forces probably lift demersal eggs up into the water column and make them available to sampling by bongo net.
YOUNG-OF-THE-YEAR AND JUVENILES Young winter flounder are ubiquitous along the east coast of the United States from Canada (McCracken 1963) to Virginia's eastern shore where Richards and Castagna (1970) found that of seventy species collected, winter flounder was the tenth most numerous. Saco Bay in Maine has young winter flounder (Casterlin and Reynolds 1982) and there was a hatchery for winter flounder for many years in Boothbay (Bigelow and Schroeder 1953). Massachusetts (Pierce-and Howe 1977; Heck et al. 1989; Saucerman 1990), Rhode Island (Saila et al. 1965; Oviatt and Nixon 1977) and Connecticut (Pearcy 1962; Richards 1963; Howell and Simpson 1994; Carlson et al. 1997; Gottschall et al., in review) are all home to young winter flounder. Briggs and O'Connor (1971) documented the presence of young winter flounder on the south shore of Long Island, New York, while Franz and Tanacredi (1992) described the food habits of young winter flounder in Jamaica Bay, New York. 'Juvenile winter flounder are a year-round resident of the NewV York Bight (Figure 5).
Juveniles are common in the inshore waters of New Jersey (Rountree and Able 1992; Sogard 1992) and Delaware (Daiber et al. 1976).
Offshore, the presence of winter flounder juveniles has been demonstrated by numerous surveys conducted by the Northeast Fisheries Science Center (Figure 3).
ADULTS Winter flounder have been captured as far north as Ungava Bay in Labrador (Kendall 1909) and as far south as Georgia (Hildebrand and Schroeder 1928). In bottom-trawl surveys conducted by the NEFSC, winter flounder adults and juveniles are common on Georges Bank and in shelf waters as far south as the mouth of Chesapeake Bay during all seasons (Figure 3).
Inshore trawl surveys in Massachusetts (Figure 4), Rhode Island (Saila 1961; Jeffries and Terceiro 1985) and Long Island Sound (Simpson et al. 1994) show them to be ubiquitous in those areas as well. Winter flounder are also common in the
Page 11 lower reaches of the Hudson River (Boyce Thompson Institute for Plant Research, Estuarine Study Group 1977; Able et al. 1999) and the New York Bight/Hudson-Raritan estuary (Phelan 1992; Figure 5). They also use other protected bays and coastal ponds along the New Jersey coast (Tatham et al. 1984).
STATUS OF THE STOCKS HISTORICAL PERSPECTIVE Commercial fisheries for winter flounder flourished prior to 1980, even in the southern end of the range.
Winter flounder was one of the dominant species in the Indian River and Rehoboth Bays in Delaware in the 1960's, but catches have since declined (Daiber et al.
1976). The commercial landings of winter flounder in 1970 in Delaware totaled only 2,300 pounds, but a moderate sport fishing effort persisted at that time especially in Indian River Bay (Daiber et al. 1976).
Hildebrand and Schroeder (1928) reported the existence of a winter commercial fishery for winter flounder in Chesapeake Bay in the 1920s; it was the principal fish caught in fyke nets in the winter (Hildebrand and Schroeder 1928).
The bulk of the landings were in Maryland, and the rest in Virginia.
The Maryland landings would seem to support the statement made by Hildebrand and Schroeder (1928) that winter flounder are more common in Maryland waters than in the lower (more southern) areas of Chesapeake Bay.
Although Hildebrand and Schroeder (1928) reported the presence of winter flounder as far south as Georgia, they also note that they were not taken in commercial numbers south of Chesapeake Bay.
Commercial landings of winter flounder peaked in the 1980s throughout its range (Brown and Gabriel 1998) and have since declined.
CURRENT STATUS OF THE STOCKS Winter flounder are currently managed as three stocks, Gulf of Maine, southern New England-Middle Atlantic, and Georges Bank (Brown and Gabriel 1998).
Both the Gulf of Maine Stock and the southern New England-Middle Atlantic stocks are considered over-exploited.
Although there is some evidence that stock rebuilding has begun on Georges Bank, stock levels remain well below the historic average (Brown and Gabriel 1998).
Biomass in the Gulf of Maine stock declined from 19,600 mt in 1979 to a low of 6,000 mt in 1991 (Brown and Gabriel 1998) (Figure 14).
The current biomass estimate for 1997 stands at 8,900 mt less than half of the 1979 value (Brown and Gabriel 1998). In the southern New England-Middle Atlantic stock, stock biomass declined from 39,000 mt in,1981 to a record low of 8,500 mt in 1992 (Brown and Gabriel 1998; Figure 14).
Contributions from strong year classes in 1992 and 1994 have rebuilt the stock biomass to 18,000 mt in 1996 but the stock remains overexploited (Brown and Gabriel 1998). The NEFSC autumn bottom trawl survey biomass index declined from the mid-1970's until 1991 when it reached a record low of 0.14 kg per tow (Brown and Gabriel 1998; Figure 14).
Although it has increased somewhat since then (1.76 kg per tow in 1996) it remains significantly below former levels (Brown and Gabriel 1998).
RESEARCH NEEDS Although we know more about winter flounder than many other species, there are many more questions waiting to be answered. The driving forces behind winter flounder movements are still poorly understood.
Temperature certainly plays a role, but does not explain all movements. The role of light intensity, food availability, and predators needs further attention.
Although we speak about spawning habitat and juvenile habitat as if they are separate things it is clear that they must be linked somehow. If spawning habitat is lost through man's activities, is the adjacent juvenile habitat lost as well for lack of juveniles to fill it?
Pinpointing and mapping of habitats through the use of GIS technology on a large scale and over different ontogenetic stages will help us to maintain a more holistic outlook on habitat.
The utilization of shallow bays and estuaries by winter flounder for spawning and nursery areas has been well documented. Less well studied is the utilization of nearby coastal waters.
Lux and Kelly (1982) found winter flounder eggs at 13 coastal stations and 3 offshore stations and larvae at 17 coastal stations and 7 offshore stations between Provincetown to Cape Ann.
A similar study by Howe (1973) also collected winter flounder eggs and larvae. Both studies generally collected relatively low densities of eggs and larvae but Howe (1973) showed that larval densities were highest at the mouths of estuaries.
These collections probably represent eggs and larvae washed out of the estuaries by tidal flushing. Subsequent beam trawling in these areas failed to collect substantial numbers of YOY flounder indicating a low survival rate.
In contrast, Marine Research, Inc. (1986) reported good growth in winter flounder larvae that had been washed out of the. Plymouth Harbor-Duxbury Bay estuary. Epibenthic sled collections of winter flounder eggs outside the estuary along the coast showed that spawning occurred there as well.
The relative contribution of this coastal spawning to winter flounder recruitment needs further study.
The different components of these "stock complexes" need to be better described and their habitat preferences and needs documented. An attempt was made in 1980 to
Page 12 separate stocks using eye lens proteins (Schenck and Saila 1982) but this effort only covered a small area near the Millstone Point area. The study showed that even in this small area there was a significant mixing of different stocks. A more comprehensive effort, spanning the entire range of the species needs to be done utilizing more modern techniques such as mitochondrial DNA.
ACKNOWLEDGMENTS The authors wish to thank C. Steimle, J. Berrien, and R. Ramsey-Cross for literature searches and bibliography preparation, S. Griesbach and L. Cargnelli for editing and formatting, and B. Phelan for reviews, comments, and additions.
REFERENCES CITED Able, K.W. and M.P. Fahay. 1998. The first year in the life of estuarine fishes in the Middle Atlantic Bight.
Rutgers University Press. New Brunswick, NJ. 342 p.
Able, K.W. and S.M. Hagan. 1995. Fishes in the vicinity of Beach Haven Ridge: annual and seasonal patterns of abundance during the early 1970s. Rutgers Univ.
Inst. Mar. Coastal Sci. Tech. Rep. 95-24.
Able, K.W., J.P. Manderson, and A.L. Studholme. 1999.
Habitat quality for shallow water fishes in an urban estuary: the effects of man-made structures on growth. Mar. Ecol. Prog. Ser. 187: 227-235.
Able, K.W., K.A. Wilson and K.L. Heck, Jr. 1989. Fishes of the vegetated habitats in New Jersey estuaries:
composition, distribution and abundance, based on quantitative sampling. Center for Coastal and Environ. Studies, Publ. No. 1041. Rutgers University, New Brunswick, NJ. 39 p.
Anonymous. 1972. Algae form a nursery for winter flounder. Maritimes 16: 13-14.
Azarovitz, T.R. 1982. Winter flounder. In M.D. Grosslein and T.R. Azarovitz eds. Fish distribution. p. 119-122.
MESA New York Bight Atlas Monograph 15. N.Y.
Sea Grant Institute, Albany, NY.
Backus, R.H. 1957. The Fishes of Labrador. Bull. Amer.
Mus. Nat. Hist. 113: 275-337.
Backus, R.H. and D.W. Bourne eds. 1987. Georges Bank.
MIT Press. Cambridge, MA. 593 p.
Battle, H.I. 1926. Effects of extreme temperatures on muscle and nerve tissues in marine fishes. Trans. R.
Soc. Can. 20: 127-143.
Beacham, T.D. 1982. Biology and exploitation of winter flounder, Pseudopleuronectes americanus, in the Canadian Maritimes area of the northwest Atlantic Ocean. Can. Tech. Rep. Fish. Aquat. Sci. 1113. 33 p.
Bejda, A.J., B.A. Phelan, and A.L. Studholme. 1992. The effect of dissolved oxygen on growth of young-of-the-year winter
- flounder, Pseudopleuronectes americanus. Environ. Biol. Fishes 34: 321-327.
Bigelow, H.B. and W.C. Schroeder. 1953. Fishes of the Gulf of Maine. U.S. Fish Wildl. Serv. Fish. Bull. 53.
577 p.
Bourne, D.W. and J.J. Govoni. 1988. Distribution of fish eggs and larvae and patterns of water circulation in Narragansett Bay, 1972-1973. In M.P. Weinstein ed.
Larval fish and shellfish transport through inlets. p.
132-148. Am. Fish. Soc. Symp. 3. American Fisher-ies Society, Bethesda, MD.
Boyce Thompson Institute for Plant Research. Estuarine Study Group. 1977. An atlas of the biologic resources of the Hudson Estuary. The Institute, Yonkers, NY.
104 p.
Breder, C.M., Jr. 1923. Some embryonic and larval stages of the winter flounder. Bull. U.S. Bur. Fish. 38: 311-315.
Brice, J.J. 1898. The flatfish, or winter flounder. Rep.
U.S. Commissioner Fish Fisheries. Part 23: 215-218.
Briggs, P.T. and J.S. O'Connor. 1971. Comparison of shore-zone fishes over naturally vegetated and sand-filled bottoms in Great South Bay. N.Y. Fish Game J.
18(1): 15-41.
Brown, R. and W. Gabriel. 1998. Winter flounder. In Clark, S.H. ed. Status of the fishery resources off the northeastern United States for 1998. p. 81-84. NOAA Tech. Mem. NMFS-NE-115 Buckley, L.J. 1982. Effects of temperature on growth and biochemical composition of larval winter flounder Pseudopleuronectes americanus. Mar. Ecol. Prog.
Ser. 8: 181-186.
Burton, M.P. and D.R. Idler. 1984. The reproductive cycle in winter
- flounder, Pseudopleuronectes americanus. (Walbaum). Can. J. Zool. 62: 2563-2567.
Carlson, J.K., T.A. Randall and M.E. Mroczka. 1997.
Feeding habits of winter flounder, Pleuronectes americanus, in a habitat exposed to anthropogenic disturbance. J. Northwest Atl. Fish. Sci. 21: 65-73.
Casterlin, M.E.
and W.W.
Reynolds.
1982.
Thermoregulatory behavior and diel activity of yearling winter
- flounder, Pseudopleuronectes americanus (Walbaum). Environ. Biol. Fishes 7: 177-180.
Chambers, R.C. and W.C. Leggett..1987. Size and age at metamorphosis in marine fishes: An analysis of labo-ratory-reared winter flounder, Pseudopleuronectes americanus, with a review of variation in other species. Can. J. Fish. Aquat. Sci. 44: 1936-1947.
Crawford, R.E. and C.G. Carey. 1985. Retention of winter flounder larvae within a Rhode Island salt pond.
Estuaries 8: 217-227.
Croker, R.A. 1965. Planktonic fish eggs and larvae of Sandy Hook estuary. Chesapeake Sci. 6: 92-95.
Curran, M.C., R.J. Chant, K.W. Able and S.M. Glenn.
1996. The role of estuarine circulation patterns in
Page 13 regulating the settlement of juvenile winter flounder, Pleuronectes americanus, in coves near ocean inlets.
Flatfish Biology Workshop: Program and abstracts.
December 3-4, 1996. p. 19-20. Mystic, CT.
- Daiber, F.C.,
L.L.
- Thornton, K.A.
- Bolster, T.G.
Campbell, O.W. Crichton, G.L. Esposito, D.R. Jones and J.M. Tyrawski. 1976. An atlas of Delaware's wetlands and estuarine resources. Delaware Coastal Management Program Tech. Rep. No. 2. College of Marine Studies, University of Delaware, Newark, DE. 528 p.
Danila, D.J. and M.J. Kennish. 1982. Tagging study of winter flounder, Pseudopleuronectes americanus, in Barnegat Bay, New Jersey. In IEEE Council of Oceanic Engineering. Oceans '81 conference record:
The ocean: an international workplace. Vol. 2. p.
759-764. Boston, MA.
Dickie, L.M. and F.D. McCracken.
1955. Isopleth diagrams to predict equilibrium yields of a small flounder fishery. J. Fish. Res. Board Can. 12: 187-209.
Dovel, W. 1967. Fish eggs and larvae of the Magothy River, Maryland. Chesapeake Sci. 8:125-129.
Dovel, W. 1971. Fish eggs and larvae of the upper Chesapeake Bay. Natural Resources Institute Special Report No. 4. Contribution No. 460. University of Maryland. 69 p.
Duffy-Anderson, J.T. and K.W. Able. 1999. Effects of municipal piers on the growth of juvenile fishes in the Hudson River estuary: a study across a pier edge.
Mar. Biol. 133: 409-418.
Everich, D. and J.G. Gonzdlez. 1977. Critical thermal maxima of two species of estuarine fish. Mar. Biol.
41: 141-145.
Fahay, M.P. 1983. Guide to the early stages of marine fishes occurring in the western North Atlantic Ocean, Cape Hatteras to the southern Scotian Shelf. J.
Northwest Atl. Fish. Sci. 4: 1-423.
Fisher, H.D. and B.A. Mackenzie. 1955. Food habits of seals in the Maritimes. Prog. Rep. Atl. Coast Stations Fish. Res. Board Can. 61: 5-9.
Frame, D.W. 1971. Biology of young winter flounder:
feeding habits, metabolism and food utilization.
Ph.D. dissertation, University of Mass. Amherst, MA. 116 p.
Frank, K.T. and W.C. Leggett. 1983. Multispecies larval fish associations: Accident or adaptation? Can. J.
Fish. Aquat. Sci. 40: 754-762.
Franz, D.R.
and J.T. Tanacredi.
1992.
Secondary production of the amphipod, Ampelisca abdita, Mills and its importance in the diet of juvenile winter flounder, Pleuronectes americanus, in Jamaica Bay, New York. Estuaries 15: 193-203.
Gibson, R.N.
1973. The intertidal movements and distribution of young fish on a sandy beach with special reference to the plaice, Pleuronectes platessa L. J. Exp. Mar. Biol. Ecol. 12: 79-102.
Gibson, R.N. and L. Robb.
1992. The relationship between body size, sediment grain size and the burying ability, of juvenile plaice, Pleuronectes platessa L. J. Fish Biol. 40: 771-778.
Goldberg, R., B. Phelan, J. Pereira, S. Hagan, P. Clark, A.
Bejda, A. Calabrese, A. Studholme, and K. Able. In preparation. Habitat-specific patterns of abundance and distribution of young-of-the-year winter flounder, Pseudopleuronectes americanus, in three northeastern U.S. estuaries. U.S. Nati. Mar. Fish.
Serv., Northeast Fish Sci. Cent., Milford. Lab.,
Milford, CT.
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.
Gould, E., P.E. Clark, and F.P. Thurberg. 1994. Pollutant effects on demersal fishes. In R.W. Langton, J.B.
- Pearce, and J.A. Gibson eds.
Selected living resources, habitat conditions, and human perturbations of the Gulf of Maine: Environmental and ecological considerations for fishery management. p. 30-41. NOAA Tech. Mem. NMFS-NE-106.
Govoni, J.J. 1973. The distribution of some marine fish eggs and larvae in the Acushnet and Westport River estuarine
- systems, Massachusetts.
M.S.
- thesis, Southeastern Massachusetts University, North Darmouth, MA. 71 p.
- Hacunda, J.S.
1981.
Trophic relationships among demersal fishes in a coastal area of the Gulf of Maine. Fish. Bull. (U.S.) 79: 775-788.
Haedrich, R.L. and S.O. Haedrich.
1974. A seasonal survey of the fishes in the Mystic River, a polluted estuary in downtown
- Boston, Massachusetts.
Estuarine Coastal Mar. Sci. 2: 59-73.
Heck, K.L. Jr., K.W. Able, M.P. Fahay and C.T. Roman.
1989. Fishes and decapod crustaceans of Cape Cod eelgrass meadows: Species composition, seasonal abundance patterns and comparison with unvegetated substrates. Estuaries 12: 59-65.
Hildebrand, S.F. and W.C. Schroeder. 1928. Fishes of Chesapeake Bay. Bull. U.S. Bur. Fish. 43(l): 366 p.
Howe, A.B. 1973. Determination of offshore winter flounder spawning. Massachusetts Div. Mar. Fish.
Rep.88-309. Boston, MA.
Howe, A.B. and P.G. Coates. 1975. Winter flounder movements, growth, and mortality off Massachusetts.
Trans. Am. Fish. Soc. 104: 13-29.
Howe, A.B., P.G. Coates and D.E. Pierce. 1976. Winter flounder estuarine year-class abundance, mortality,
Page 14 and recruitment. Trans. Am. Fish. Soc. 105: 647-657.
Howell, P., A. Howe, M. Gibson, and S. Ayvazian. 1992.
Fishery Management Plan for inshore stocks of winter flounder, Pleuronectes americanus. Fisheries Management Report of the Atlantic States Fisheries Commission, No. 21. 138 p.
Howell, P.T. and D.R. Molnar. 1995. A study of marine recreational fisheries in Connecticut. Inshore survey of juvenile winter flounder. Job 3. p. 55-78. Federal Aid to Sport Fish Restoration F54R, Final report.
March 1, 1989-February 28, 1995. Connecticut Dep.
Environ. Prot. Fish. Div. Old Lyme, CT.
Howell, P. and D. Simpson. 1994. Abundance of marine resources in relation to dissolved oxygen in Long Island Sound. Estuaries 17: 394-402.
- Hughes, J.B.
In preparation.
Cytological-cytogenetic analyses of winter flounder embryos from benthos at the barge North Cape oil spill. U.S. Nat]. Mar. Fish.
Serv., Northeast Fish Sci. Cent., Milford. Lab.,
Milford, CT.
Huntsman, A.G. and M.I. Sparks. 1924. Limiting factors for marine animals. 3. Relative resistance to high temperatures. Contrib. Can. Biol., New Ser. 2(6): 95-114.
Itzkowitz, N. and J.R. Schubel. 1983. Tolerance of five-day-old winter
- flounder, Pseudopleuronectes americanus, larvae to thermal shock. Fish. Bull.
(U.S.) 81: 913-916.
Jeffries, H.P. and M. Terceiro. 1985. Cycle of changing abundances in the fishes of the Narragansett Bay area. Mar. Ecol. Prog. Ser. 25: 239-244..
Kendall, W. 1909. The fishes of Labrador. Proc. Portland Soc. Nat. Hist. 2: 207-243.
Kennedy, V.S. and D.H. Steele.
1971.
The winter flounder, Pseudopleuronectes americanus, in Long Pond, Conception Bay, Newfoundland. J. Fish. Res.
Board Can. 28: 1153-1165.
Klein-MacPhee, G. In preparation. Winter flounder, Pseudopleuronectes americanus, (Walbaum 1792).
In B.B. Collette and G. Klein-MacPhee eds. Bigelow and Schroeder's fishes of the Gulf of Maine.
Smithsonian Institution Press, Washington, DC.
Klein-MacPhee, G., B.K. Sullivan and A.A. Keller. 1993.
Using mesocosms to assess the influence of food resources and toxic materials on larval fish growth and survival. Am. Fish. Soc. Symp. 14: 105-116.
Kruuk, H. 1963. Diurnal periodicity in the activity of the common sole, Solea vulgaris Quensel. Neth. J. Sea Res. 2: 1-28.
Laurence, G.C. 1975. Laboratory growth and metabolism of the winter
- flounder, Pseudopleuronectes americanus, from hatching through metamorphosis at three temperatures. Mar. Biol. 32: 223-229.
Lee, V., L. Ernst, and J. Marino. 1997. Rhode Island salt pond water quality: salt pond watchers monitoring data, 1985-1994, well and stream monitoring data, 1994. Technical report. October 1997. Coastal Resources Center, University of Rhode Island, Narragansett, RI.
Levings, C.D. 1974. Seasonal changes in feeding and particle selection by winter
- flounder, Pseudopleuronectes americanus. Trans. Am. Fish.
Soc. 103: 828-832.
Linton, E. 1921. Food of young winter flounders. Rep.
U.S. Commissioner Fish. Appendix 4: 3-14.
- Locke, A.
and S.C. Courtenay.
1995.
Effects of environmental factors on ichthyoplankton communities in the Miramichi estuary, Gulf of St.
Lawrence. J. Plankton Res. 17: 333-349.
Lux, F.E. 1973. Age and growth of the winter flounder, Pseudopleuronectes americanus, on Georges Bank.
Fish. Bull. (U.S.) 71: 505-512.
Lux, F.E. and G.F. Kelly. 1982. Icthyoplankton studies of Cape Cod and Massachussetts Bays, 1976-1977. U.S.
Nati. Mar. Fish. Serv. Northeast Fish. Cent. Woods Hole Lab. Ref. Doc. 81-43. 14 p.
Lux, F.E. and J.V. Mahoney. 1972. Predation by bluefish on flatfishes. Mar. Fish. Rev. 34(7-8): 30-35.
Lux, F.E.; A.E. Peterson, Jr. and R.F. Hutton. 1970.
Geographical variation in fin ray number in winter
- flounder, Pseudopleuronectes americanus (Walbaum), off Massachusetts. Trans. Am. Fish. Soc.
99: 483-488.
Macdonald, J.S. 1983. Laboratory observations of feeding behavior of the ocean
- pout, Macrozoarces americanus, and winter
- flounder, Pseudopleuronectes americanus, with reference to niche overlap of the populations. Can. J. Zool. 61:
539-546.
Macdonald, J.S. and R.H. Green. 1986. Food resource utilization by five species of benthic feeding fish in Passamaquoddy Bay, New Brunswick. Can; J. Fish.
Aquat. Sci. 43: 1534-1546.
Manderson, J.P., B.A. Phelan, A.J. Bejda, L.L. Stehlik, and A.W. Stoner. 1999. Predation by striped searobin (Prionotus evolans, Triglidae) on young-of-the-year winter flounder (Pseudopleuronectes americanus, Walbaum): examining prey size selection and prey choice using field observations and laboratory experiments. J. Exp. Mar. Biol. Ecol. 242: 211-231.
Manderson, J.P., B.A. Phelan, A.W. Stoner, and J.
Hilbert. In review. Predator-prey relations between 1 +
summer flounder (Paralichthys dentatus, Linnaeus) and age-0 winter flounder (Pseudopleuro-nectes americanus, Walbaum): predator diets, prey selection, and effects of sediments and macrophytes.
J. Exp. Mar. Biol. Ecol.
Mansfield, A.W.
1967. Seals of arctic and eastern Canada. Bull. Fish. Res. Board Can. 137. 35 p.
- Mansueti, R.J.
1962 Distribution of small, newly metamorphosed sea lampreys, Petromyzon marinus, and their parasitism on
- menhaden, Brevoortia tyrannus, in mid-Chesapeake Bay during the winter months. Chesapeake Sci. 3: 137-139.
Page 15 Marine Research Inc. 1986. Winter flounder early life history studies related to operation of Pilgrim Station:
A review of 1975-1984. Boston Edison Company.
Ill p.
Martell, D.J. and G. McClelland. 1994. Diets of sympatric flatfishes, Hippoglossoides platessoides, Pleuro-nectes ferrugineus, Pleuronectes americanus, from Sable Island Bank, Canada. J. Fish Biol. 44: 821-848.
Martin, F.D. and G.E. Drewry. 1978. Development of fishes of the Mid-Atlantic Bight: An atlas of egg, larval, and juvenile stages. Vol. 6: Stromateidae through Ogcocephalidae. U.S. Fish Wildl. Serv. Biol.
Serv. Prog. FWS/OBS-78/12. 416 p.
Mayo, R.K. 1994. Life histories and habitat requirements of demersal fishes. In R.W. Langton, J.B. Pearce, and J.A. Gibson eds. Selected living resources, habitat conditions, and human perturbations of the Gulf of Maine: Environmental and ecological considerations for fishery management. p. 2-6. NOAA Tech. Mem.
NMFS-NE-106.
McCracken, F.D. 1963. Seasonal movements of the winter flounder, Pseudopleuronectes americanus, (Walbaum) on the Atlantic coast.-J. Fish. Res. Board Can. 20: 551-586.
Medcoff, J.C. and J.S. McPhail.
1952. The winter flounder-a clam enemy. Prog. Rep. Atd. Coast Stations Fish. Res. Board Can. 52(118): 3-7.
Monteleone, D.M. 1992. Seasonality and abundance of ichthyoplankton in Great South Bay, New York.
Estuaries 15: 230-238.
Northeast Utilities Service Company. 1984. Monitoring the marine environment of Long Island Sound at Millstone Nuclear Power
- Station, Waterford, Connecticut. Annual report, 1983. 285 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.
O'Connor, M.
1997. Asessment of abundance and distribution of young-of-the-year winter flounder, Pleuronectes americanus, in Point Judith Pond. M.S.
thesis, University of Rhode Island, Narrangansett, RI.
41 p.
Olla, B.L., R. Wicklund and S. Wilk. 1969. Behavior of winter flounder in a natural habitat. Trans. Am. Fish.
Soc. 98: 717-720.
Oviatt, C.A. and S.W. Nixon. 1977. The demersal fish of Narragansett Bay:
An analysis of community structure, distribution and abundance. Estuarine Coastal Mar. Sci. 1: 361-378.
Payne, J. and L. Seizer. 1989. The distribution, abundance and selected prey of the harbor seal, (Phoca vitulina concolor), in southern New England. Mar. Mamm.
Sci. 5(20): 173-192.
Pearcy, W.G. 1962. Ecology of an estuarine population of winter flounder, Pseudopleuronectes americanus (Walbaum). Parts I-IV. Bull. Bingham Oceanogr.
Collect. 18(1): 5-78.
Pepin, P., S. Pearre, Jr., and J.A. Koslow. 1987. Predation on larval fish by Atlantic
- mackerel, Scomber scombrus, with a comparison of predation by zooplanton. Can. J. Fish. Aquat. Sci. 44: 2012-1018.
Pereira, J.J., R. Goldberg, P.E. Clark, and D.M. Perry.
1994. Utilization of the Quinnipiac River and New Haven Harbor by winter flounder, Pleuronectes americanus, as a spawning area. Final report to the New Haven Foundation. New Haven, CT. 30 p.
Perlmutter, A. 1947. The blackback flounder and its fishery in New England and New York. Bull.
Bingham Oceanogr. Collect. 11(2): 92 p.
Phelan, B.A. 1992. Winter flounder movements in the inner New York Bight. Trans. Am. Fish. Soc. 121:
777-784.
Phelan, B.A., R. Goldberg, A.J. Bejda, J. Pereira, S.
Hagan, P. Clark, A.L. Studholme, A. Calabrese, and K.W. Able. In press. Estuarine and habitat-related differences in growth rates of young-of-the-year winter flounder (Pseudopleuronectes americanus) and tautog (Tautoga onitis) in three northeastern U.S.
estuaries. J. Exp. Mar. Biol. Ecol.
Phelan, B.A., J.P. Manderson, A.W. Stoner, and A.J.
Bejda.
In preparation.
Ontogenetic sediment associations in young-of-the-year winter flounder (Pseudopleuronectes americanus) - evidence from field observations and laboratory experiments. U.S.
Natl. Mar. Fish. Serv., Northeast Fish Sci. Cent.,
James J. Howard Mar. Sci. Lab., Highlands, NJ.
Pierce, D.E. and A.B. Howe. 1977. A further study on winter flounder group identification off Massachusetts. Trans. Am. Fish. Soc. 106: 131-139.
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. 1969. A study of winter flounder mortality rates in Great South Bay, New York. Trans. Am.
Fish. Soc. 98: 611-616.
Powell, J.C. 1989. Winter flounder tagging study, 1986-1988 with comments on movements. Rhode Island Div. Fish and Wildl. 19 p.
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.
Reynolds, W.W. 1977. Fish orientation behavior: an electronic device for studying simultaneous responses to two variables. J. Fish. Res. Board Can. 34: 300-304.
Reynolds, W.W. and M.E. Casterlin.
1985.
Vagile macrofauna and the hydrographic environment of the Saco River. Hydrobiologia 128: 207-215.
Reynolds, W:W. and D.A. Thomson. 1974. Ontogenetic change in the response of the Gulf of California grunion, Leuresthes sardina (Jenkins & Evermann),
to a salinity gradient. J. Exp. Mar. Biol. Ecol. 14:
211-216.
Page 16 Richards, C.E. and M. Castagna. 1970. Marine fishes of Virginia's Eastern Shore (inlet and marsh, seaside waters). Cheasapeake Sci. 11: 235-248.
Richards, S.W. 1963. The demersal fish population of Long Island Sound.
Bull.
Bingham Oceanogr.
Collect. 18(2): 101 p.
Richards, S.W., J.M. Mann, and J.A. Walker. 1979.
Comparison of spawning seasons, age, growth rates, and food of two sympatric species of searobins, Prionotus carolinus and Prionotus evolans, from Long Island Sound. Estuaries 2(4): 255-268.
Rogers, C.A. 1976. Effects of temperature and salinity on the survival of winter flounder embryos. Fish. Bull.
(U.S.) 74: 52-58.
Rountree, R.A. and K.W. Able. 1992. Fauna of polyhaline subtidal marsh creeks in southern New Jersey:
Composition, abundance and biomass. Estuaries 15:
171-185.
Saila, S.B. 1961. A study of winter flounder movements.
Limnol. Oceanogr. 6: 292-298.
Saila, S.B. 1962. Proposed hurricane barriers related to winter flounder movements in Narragansett Bay.
Trans. Am. Fish. Soc. 91: 189-195.
Saila, S.B., D.B. Horton, and R.J. Berry. 1965. Estimates of the theoretical biomass of juvenile winter flounder, Pseudopleuronectes americanus, (Walbaum) required for a fishery in Rhode Island. J. Fish. Res.
Board Can. 22: 945-954.
Saucerman, S.
1990.
- Movement, distribution and productivity of post metamorphic winter flounder, Pseudopleuronectes americanus, in different habitat types in Waquoit Bay, Massachusetts. M.S. thesis, University of Massachusetts, Amherst, MA. 87 p.
Saucerman, S.E. and L.A. Deegan. 1991. Lateral and cross-channel movement of young-of-the-year winter flounder (Pseudopleuronectes americanus) in Waquoit Bay, Massachusetts. Estuaries 14: 440-446.
Scarlett, P.G. 1983. Life history investigations of marine fish - occurrence and movements of blue crabs and winter flounder from selected New Jersey estuaries.
Ann. Rep. New Jersey Dep. Environ. Prot. Div. Fish, Game and Wildl. Tech. Ser. 83-6. Trenton, NJ. 35 p.
Scarlett, P.G. 1991. Temporal and spatial distribution of winter flounder, Pseudopleuronectes americanus, spawning in the Navesink and Shrewsbury Rivers, New Jersey. New Jersey Dep. Environ. Prot. Div.
Fish, Game and Wildl. Mar. Fish. Adm. Bur. of Mar.
Fish., Trenton, NJ. 12 p.
Scarlett, P.G. and R.L. Allen. 1989. Results of fall and winter ichthyoplankton sampling in the Manasquan
- River, 1984-1986.
New Jersey Department of Environmental Protection. Division of Fish, Game and Wildlife.
Marine Fisheries Administration.
Bureau of Marine Fisheries. 37 p.
Schenck, R.
and S. Saila.
1982. Final report for:
Population identification by biochemical methods -
with special reference to the winter flounder, Pseudopleuronectes americanus, in the vicinity of Millstone Point, Connecticut.
Northeast Utilities Service Co. Contract No. P.O. #001122. 47 p.
Scott, W.C.M. 1929. A note on the effect of temperature and salinity on the-hatching of eggs of the winter
- flounder, Pseudopleuronectes americanus, (Walbaum). Contrib. Can. Biol. Fish. New Ser. 4(1-11): 139-141.
Simpson, D.G., M.W. Johnson and K. Gottschall. 1994. A study of marine recreational fisheries in Connecticut.
Marine finfish survey. Job 2. p. 13-25. Connecticut Dep. Environ. Prot. Fish. Div. Old Lyme, CT.
Sogard, S.M. 1992. Variability in growth rates of juvenile fishes in different estuarine habitats. Mar. Ecol. Prog.
Ser. 85: 35-53.
Sogard, S.M. and K.W. Able. 1991. A comparison of eelgrass, sea lettuce, macroalgae, and marsh creeks as habitats for epibenthic fishes and decapods. Estuarine Coastal Shelf Sci. 33: 501-519.
Stehlik, L.L. and C.J. Meise. In press. Diet of winter flounder in a New Jersey estuary: ontogenetic change and spatial variation. Estuaries.
Steimle, F.W., D. Jeffress, S.A. Fromm, R.N. Reid, J.J.
Vitaliano and A.
Frame.
1993.. Predator-prey relationships of winter
- flounder, Pleuronectes americanus, in the New York Bight apex. Fish. Bull.
(U.S.) 92: 608-619.
Stoner, A.W., A.J. Bejda, J.P. Manderson, B.A. Phelan, L.L. Stehlik and J.P. Pessutti. 1999. Behavior of winter flounder, Pseudopleuronectes americanus, during the reproductive season: laboratory and field observations on spawning, feeding and locomotion.
Fish. Bull. (U.S.) 97: 999-1016.
Sumner, F.B. 1907. Further studies of the physical and chemical relations between fishes and their surrounding medium. Amer. J. Physiol. 19: 61-96.
Tatham, T.R., D.L. Thomas and D.J. Danila. 1984. Fishes of Barnegat Bay. In M.J. Kennish and R.A. Lutz eds.
Ecology of Barnegat Bay, New Jersey. p. 241-280.
Lecture Notes on Coastal and Estuarine Studies No.
- 6. Springer-Verlag. New York, NY.
Topp, R.W. 1968. An estimate of fecundity of the winter flounder, Pseudopleuronectes americanus. J. Fish.
Res. Board Can. 25: 1299-1302.
Tyler, A. V. 1971 a. Periodic and resident components in communities of Atlantic Fishes. J. Fish. Res. Board Can. 28: 935-946.
- Tyler, A.V.
1971b.
Surges of winter
- flounder, Pseudopleuronectes americanus, into the intertidal zone. J. Fish. Res. Board Can. 28: 1727-1732.
Tyler, A.V. and R.S. Dunn. 1976. Ration, growth, and measure of somatic and organ condition in relation to meal frequency in winter
- flounder, Pseudopleuronectes americanus, with hypotheses regarding population homeostasis. J. Fish. Res. Board Can. 33: 63-75.
Van Guelpen, L. and C. C. Davis. 1979. Seasonal move-
Page 17 ments of the winter flounder, Pseudopleuronectes americanus, in two contrasting inshore locations in Newfoundland. Trans. Am. Fish. Soc. 108: 26-37.
Warfel, H.E. and D. Merriman. 1944. Studies on the marine resources of southern New England. Bull.
Bingham Oceanogr. Collect. 9: 1-91.
Weber, A.M. 1984. Winter flounder in western Long Island Sound: Preliminary results of the 1981-1983 tagging projects. New York State Dep. Environ.
Conserv. Div. Mar. Resour. Stony Brook, NY. 33 p.
Weber, A.M. and C.S. Zawacki. 1983. Winter flounder tagging in western Long Island Sound. New York State Dep. Environ. Conserv. 'Bur. Finfish and Crustaceans. SUNY, Stony Brook, NY. 4 p.
Williams, G.C. 1975. Viable embryogenesis of the winter flounder, Pseudopleuronectes americanus from -1.8 to 15'C. Mar. Biol. 33: 71-74.
Williams, P.J., and J.A. Brown, 1992. Development changes in the escape response of larval winter
- flounder, Pleuronectes americanus, from hatch through metamorphosis. Mar. Ecol. Prog. Ser. 88:
185-193.
Witting, D. A. 1995. Influence of invertebrate predators on survival and growth of juvenile winter flounder.
Ph.D. dissertation. Rutgers Univ., New Brunswick, NJ.
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. and K.W. Able.
1995. Predation by sevenspine bay shrimp, Crangon septemspinosa, on winter flounder, Pleuronectes americanus, during settlement: laboratory observations. Mar. Ecol. Prog.
Ser. 123: 23-31.
Ziskowski, iJ. J. Pereira. D. Miller and J. Sewell. 1991.
Winter flounder:
Living in a hypoxic world.
Northeast Fisheries Center Research Meeting, Woods Hole, MA. I p.
Page 18 Table 1. Summary of life history and habitat parameters for winter flounder, Pseudopleuronectes americanus.
Life Stage Temperature Salinity Dissolved Oxygen Spawning initiated at Found from 10-32 ppt; Found at 11.1-14.2 mg/l.
Eggs '
about 3"C; salinity has little effect on highest percent hatch survival or hatch.
at 3-5"C; 18"C lethal.
No feeding or Found at 3.2-30 ppt; higher Found at 10.0-16.1 mg/I.
Larvae 2 metamorphosis at 2"C; on Georges Bank.
hatch from 1-I2TC; larvae most abundant at 2-15"C.
Found at 2-29.4"C; Found at 23-33 ppt; Constant 2.2 mg/I or diurnal variation Yoy '
Laboratory study suggests 5 ppt suggested by from 2.6-6.4 mg/I adversely affects preferred temperature is laboratory study as lower growth.
19.5"C; avoidance salinity.
30"C may be lethal.
Commonly found at 10-Collected 19-21 ppt; Juveniles 4 25"C during summer and 10 ppt suggested as lower fall.
avoidance level.
0.6-23"C; Found at 15-33 ppt.
Lower dissolved oxygen associated with Adults 12-15"C suggested as lower mean length of catch suggesting preferred; avoidance by larger fish or reduced upper incipient lethal limit growth.
is 27"C.
Breder 1923; Scott 1929; Bigelow and Schroeder 1953; Pearcy 1962; Williams 1975; Rogers 1976; Buckley 1982; Crawford and Carey 1985; Scarlett and Allen 1989; Monteleone 1992 2 Bigelow and Schroeder 1953; Pearcy 1962; Dovel 1967, 1971; Buckley 1982; Frank and Leggett 1983; Scarlett and Allen 1989; Monteleone 1992 3 Pearcy 1962; Richards and Castagna 1970; Briggs and O'Connor 1971: Oviatt and Nixon 1977; Pierce and Howe 1977; Reynolds and Casterlin 1985; Heck et al. 1989; Bejda et al. 1992; Rountree and Able 1992 4 Pearcy 1962; Oviatt and Nixon 1977; Casterlin and Reynolds 1982; Reynolds and Casterlin 1985; Carlson et al. 1997
- 5 Breder 1923; McCracken 1963; Olla et al. 1969; Richards and Castagna 1970; Haedrich and Haedrich 1974; Howe and Coates 1975; Tyler and Dunn 1976; Oviatt and Nixon 1977; Van Guelpen and Davis 1979; Jeffries and Terceiro 1985; Reynolds and Casterlin 1985; Howell and Simpson 1994; Carlson et a/. 1997
Page 19 Table I. cont'd.
Life Stage Depth Substrate Vegetation Currents Found at 0.3-4.5 m (inshore);
Mud to sand or Diatom mats, Eggs 90 m or less on Georges
- gravel, drifting macroalgae.
Bank.
1-4.5 m inshore.
Fine sand, gravel.
Hydrodynamics Larvae 2 work to retain larvae in nursery areas.
0.5-12 m inshore.
Mud to sand with Ulva, eelgrass and YOY 3 shell or leaf litter.
unvegetated adjacent areas.
Peak abundance of flounder Equally abundant on Juveniles 4 less than 200 mm occurs in mud or sand shell.
18-27 m of water in Long Island Sound in April and May. In Canadian waters, juveniles were most abundant at I I-18 m.
Less than 100 m offshore.
Most 1-30 m inshore, Mud, sand, cobble, Adults 5 shallowest during spawning; rocks, boulders.
less than 100 m offshore.
Scott 1929: Bigelow and Schroeder 1953; Pearcy 1962; Anonymous 1972; Crawford and Carey 1985; Scarlett and Allen 1989; Monteleone 1992 Pearcy 1962; Frank and Leggett 1983; Crawford and Carey 1985; Scarlett and Allen 1989; Monteleone 1992 Briggs and O'Connor 1971 Heck et al. 1989; Saucerman 1990; Sogard 1992; Howell and Molnar 1995; Gottschall et al., in review McCracken 1963; Richards 1963 5 Breder 1923; Mansueti 1962; McCracken 1963; Olla et al. 1969; Kennedy and Steele 1971; Van Guelpen and Davis 1979; Macdonald and Green 1986; Steimle et al. 1993
Page 20 Table 1. cont'd.
Life Stage Predators Prey Migration Eggs'
- Mackerel, Nauplii, Larvae 2 Sarsia tubulosa invertebrate eggs, protozoans, polychaetes Crangon sp.,
Amphipods, Limited; YOY I summer flounder,
- copepods, deeper for first winter.
striped searobin polychaetes, (Prionotus evolans) bivalve siphons Cormorants, Sand dollars, Movement to deeper waters as size Juveniles 4 snapper bluefish, bivalve siphons, increases.
gulls polychaetes, amphipods, Crangon sp.
Goosefish, Amphipods, Inshore in fall; Adults 5 spiny dogfish, polychaetes, offshore in spring; long post-spawn sea ravens, bivalves or siphons, migrations in some fish.
striped bass, capelin eggs,
- seals, crustaceans sculpins I Pearcy 1962, Dovel 1971; Frank and Leggett 1983 Linton 1921; Poole 1964; Saucerman 1990; Saucerman and Deegan 1991; Witting and Able 1993; Howell and Molnar 1995; Witting and Able 1995; Manderson et al. 1999; Stehlik and Meise, in press 4 Linton 1921; Howe et al. 1976; Reynolds and Casterlin 1985; Franz and Tanacredi 1992; Carlson et al. 1997; Stehlik and Meise, in press Medcoff and MacPhail 1952; Bigelowand Schroeder 1953; Dickie and McCracken 1955; Fisher and Mackenzie 1955; Saila 1961; Mansfield 1967; Olla et al. 1969; Kennedy and Steele 1971; Tyler 1971a; Haedrich and Haedrich 1974; Howe and Coates 1975; Tyler and Dunn 1976; Van Guelpen and Davis 1979; Azarovitz 1982; Macdonald 1983; Jeffries and Terceiro 1985: Macdonald and Green 1986; Phelan 1992; Martell and McClelland 1994; Steimle et al. 1993; Carlson et al. 1997
Page 21 Figure I. The winter flounder, Pseudopleuronectes americanus (Walbaum) (from Goode 1884).
Page 22 a) 1973-1980 I-10cm n=5 11-20cm n=124 Ericthonius rubricom. 13.3%
Animal Remains 13.31%
,/..*.
- .*.Maldanidae 13.3%
Undola irrorata 15.7%
Unciola irrorata 6.7%
Gammaridea 9.2%
Trichobranchus glacia. 6.7%
Nereis sp. 6.7%
Leptocheinis pinguis 9.2%
Lumbrineris fragilis 6.7%
Ampharetidae 7..
Animal Remains 18.8%
Flabelligendae 3.9%
Cerianthidae 3.9%
Ampharetidae 6.6%
Maldanidae 7.0%
6 /
,Polychaeta 6.7%
21-30 cm n=412 Animal Remains 18.9%
31-70 cm n=496 Animal Remains 12.0%
Uncola irrorata 13.6%
Ganmnaddea Aeginina longicomis 6.3%
Leptocheims pinguis 9.9%
Aeginina longicomis I I
Figure 2. Abundance (percent occurrence of 10 most common prey items) of the major prey items of winter flounder, by size class, collected during NEFSC bottom trawl surveys from 1973-1980 and 1981-1990. 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 23 b) 1981-1990 11-20 cm n=70 Potychaeta 53.6%
Crangon septemsp. 1.2%
Isopoda 2.4%
Plants 3.6%
Crustacea shrimp 3.6%
Decapoda shrimp 1.2%
Actlnaria 3.6%
.Hydrozoa 6.0%
Animal Remains 11.9%
Amphipoda 13.1%
21-30 cm 31-70 cm n=328 n=396 Isopoda 1.2%
Polychaeta 52.3%
e Polychaea 57.9% :
Bryozoa 1.5%
Custacea 1.8%
Polyehaeta 579%
,,Actinaria 1.7%
Isopoda 2.4%
Plants 2.2%
Plants 2.9%
Hydrozoa 2.9%
Bvala 3.3%
Bivalvia 3.2%
Bryozoa 3.5%
Gammaridea 5.8%
Gammaridea 4.5%
\\ Actinaria 6.3%
Animal Remains 10.7%
Animal Remains 13.0%
Amphipoda 10.0%
,Arpnipoda 12=.9%o Figure 2. cont'd.
Page 24 Figure 3. Distribution and abundance of juvenile and adult winter flounder collected during NEFSC bottom trawl surveys during all seasons from 1963-1997. Densities are represented by dot size in spring and fall plots, while only presence and absence are represented in winter and summer plots [see Reid et al. (1999) for details].
Page 25 Winter Flounder NMFS Trawl Surveys Spring 1968-97 Adults (>=27cm)
Numberfow I to 25 S25 t 50 50 lo I00 0
100 To 400 4M) mf 450 Winter Flounder NMFS Trawl Surveys Autumn 1963 - 96 Adults (>=27cm)
Winter Flounder NMFS Trawl Surveys Winter 1964-97 Adults (>=27cm) x = Absent 0 = Present Number/Tow I to 15 15 to 5ff 50 to 1O0 Iff) to 2(0M 200f to 288 Figure 3. cont'd.
Page 26 winter Flounder Mass. Inshore Trawl Survey WSpring 1978 -1996 Juveniles (<27cm) 7%,
Nt,mhcr/Tow, I to 50 50 to 2()
62005In500
" "500' : (0)
IWO to 17842
- ,4 :*:....
o..:
Winter Flou Mass. Inshore Tr 1
f*
- ""Spring 1978.
Adults (>=7 6
0525(
- 250 0 5O5.
V
- S i -..
41
-v *7 f-.."
- 'd 2
"1".,
under raw lS~urve y 27cm) 50 250) 25 Io5(m) lo 626 Figure 4. Distribution and abundance of juvenile and adult winter flounder in Massachusetts coastal waters collected during the spring and autumn Massachusetts trawl surveys, 1978-1996 [see Reid et al. (1999) for details].
Page 27 NEW NEW WinterORK Wlounderounder NW YORK Wiinter Flounde Hudson-Raritan Estuary Hudson-Raritan Estuary 0-Winter 1992-1997 Spring 1992 - 1997 Juveni les (<28 cm)
° Juveniles (<28 cm)
° Stan
.Satn Island Island NEW
- 04
-E,,
NEWW
- ew YORK NE Winter Flounder Winter Flounder YoRK Hudstn-Raritan Estuary Hudson-Raritan Estuary 0
Juveniles (<28 cm)
°.
Juveniles (<28 em)
- wc Staten
°***
° Statnen o
S Island W*.
Island O.
a.
I-
-°o 9
° 6_24o I0~
229 2549 NEW 50 99 NEW r*
JERSEY 3*5 JERSEY 1932.
Figure 5. Distribution and abundance of juvenile and adult winter flounder collected in the Hudson-Raritan estuary, based on Hudson-Raritan trawl surveys during winter (January-March), spring (April and June), summer (July-August),
and fall (October-December) from January 1992 to June 1997 [see Reid et al. (1999) for details].
Page 28
/
- o NEW.
Winter Flounder Hud.sn-Raritan Eswtury Fall 1992 - 1996 Adults(>27cm)
I staS.
fa..
o NEW 024_9 JERSEY 32.-9 Figure 5. cont'd.
Page 29 Winter Flounder Eggs a-80 60 20 10 68 30 20 10 0
50 40 30 20 10 0
50 40 30 20 10 0
80 60 20 t0 0
April May
- i.
June 0
4 6
8 10 12 14 16 18 20 22 24 26 28 Water-Column Temperature (0-200m, C) ll on 20 20100 l j *,
February
=
Stations Egg Catch 0
-r 60j 40 200oI~
March g~301 N
S20-1
~
E to0 April 0
LA ý11 1ý q Z4 1ý Eý 2ý Cý q ý I
50 -
40 May 30 20 -
80 June 20 Bottom Depth (m), Interval Midpoint
-3 Figure 6. Abundance of winter flounder eggs relative to water column temperature (to a maximum of 200 m) and bottom depth from NEFSC MARMAP ichthyoplankton surveys, February to June, 1978-1987 (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 M 2).
Page 30 0L 70 60 20 10 0
40 30 20 10 0
40 30 20 10 0
30 20 10 0
20 10 0
100 80 10 0
Winter Flounder Larvae IMarch Stations
-,Larva Catch April May June July
~-
4,
,-1((
t
~
-1 " --
September 0
2 4
6 8
10 12 14 16 18 20 22 24 26 28 Water-Column Temperature (0-200m, C)
K, t 40 0 20 -
March Stations Larva Catch n -
404.
30 -j 20 -~r 10 -l~
April 60 40 May 20 80 20 June 20 0.
-M '9
.9- -1 80
- Jul 100 8o September 20 Bottom Depth (m), Interval Midpoint April I;
Figure 7. Abundance of winter flounder larvae relative to water column temperature (to a maximum of 200 m) and bottom depth from NEFSC MARMAP ichthyoplankton surveys, March to September, 1977-1987 (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/l 0 M2 ).
Page 31 Winter Flounder NMFS Bottom Trawl Surveys 0Catches 40 30' 20 10" Juveniles Spring 40=
30' 20' I0" Adults Spring A
1 3 5 7 9 11 1315171921 23252729 Bottom Temperature (C) 2D' kAutumn 25' 01 e
3 5 7 9 11 13 15 17 19 21 23 25 27 29 Bottom Temperature (C) 3 "5" V7 '9' 1'
'9 3
1 15 17"19212 9
ii 25' Bottom Temperature (C) n I~4 I~g999'I~'~'r'-~,. *-
20' 16' 12' 4-Autumn Jiinhi-.-
50 40 30" 20' 10'Il ln nn nn -
Spring 0 -
I 3 5 7 9 11 13 15 17 19 21 23 25 27 29 Bottom Temperature (C) 10" 30-Spring 20" to-N Bottom Depth (in) 50-40-Autumn 30-to 0
0 o
I-ad Q S dA.)C.
n ' m
'*."?
m *
'I
. ' 1 Bottom Depth (m) 70" 60' 50 40' 30, 20 10"lnnnný Autumn U
Bottom Depth (m) v Bottom Depth (m)
Figure 8. Abundance of juvenile and adult winter flounder relative to bottom water temperature and depth based on spring and autumn NEFSC bottom trawl surveys. 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 32 Winter Flounder Mass. Inshore Trawl Surveys E" Stations 0 Catches Spring Juveniles 15" 12-9-
63 3-IL Is Spring 12 9
6 3
Adults I -- aummmmmmmm m
L m
20-16-12' 8-4-
3 5
7 9
11 13 15 17 19 21 23 Bottom Temperature (C)
NIT 1
3 5
7 9
11 13 15 17 19 21 23 Bottom Temperature (C) iir 20 Autumn 16 12 S
4 Auturmn hWIIIý H mm u lL m
m mmmmm mm 1
m 0 J Iq q 0 i F. ýJ IR i
1 3
5 7
9 11 13 15 17 19 21 23 Bottom Temperature (C)
V¸ 13 5
7 9
11 13 15 17 19 21 23 Bottom Temperature (C) 25 30 20-Spring Spring 10-5-10" 10' B
.o.t.
.(in Bottom Depth (m)
Botto
,(in Bottom Depth (m) 25 20" 10" Autumn Autumn 15 5
R(flff-m--
Bottom Depth (m)
Bottom Depth (m)
Figure 9. Abundance of juvenile and adult winter flounder relative to bottom water temperature and depth based on Massachusetts inshore bottom 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 In2).
Page 33 Juveniles (<28 cm) 10 8-6-
4-2 0 0 2
4 6
8 10 12 14 16 18 20 22 24 26 Temperature (C) 25 20 15 10" 5'
SIJ stations Catches
'Fir'IFI F. -
I I
U 0
1 2
3 4
5 6
7 8
9 10 11 Dissolved Oxygen (mg/l)
[12 13 A4 35-30 25 20 15 10 5-I I'mitul-M-1 M 0.)
V 0)
II I I II I
0 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 15 Depth (ft)
Adults (>27 cm) 23 25 27 29 31 33 35 Salinity (ppt) 14 EIl] Stations 12-I Catches 2
8 25-t_
20-15" 10" 5"
HFL1h1FVI 0
2 4
6 8
10 12 14 16 18 20 22 24 26 Temperature (C) 35-30-t! 25-
.20 S15-10-5-
C.)
0.
0 -
1 1
1 1
0 1 2 3
4 5
6 7
8 9
10 11 12 13 Dissolved Oxygen (mg/I) 12' 10" 8-6 4
2 0~
15 17 19 21 23 25 27 29 31 33 35 Salinity (ppt)
I FIFE VIFru-U-jIE-U II ml II I
U..............................................
10 15 20 25 30 35 40 45 50 55 60 65 70 75 Depth (ft) 80 85 Figure 10. Abundance of juvenile and adult winter flounder relative to bottom water temperature, dissolved oxygen, depth, and salinity from Hudson-Raritan estuary trawl surveys (January 1992 - June 1997, all years combined).
Page 34 Figure 11. Distribution and abundance of winter flounder from Newfoundland to Cape Hatteras based on research trawl surveys conducted by Canada (DFO) and the United States (NMFS) from 1975-1994 (http://www-orca.nos.noaa.gov/
projects/ecnasap/ecnasapjtable I.html).
Page 35 Winter Flounder Winter Flounder 44-Eggs 44 Eggs MARMAP Ichthyoplankton Surveys MARMAP Ichthyoplankton Surveys 61-cm Bongo Net; 0.505-mm mesh 61-cm Bongo Net 0.505-mm mesh February to June; 1978 to 1987 February; 1978 to 1987 42--
4 -.
?
~
j..-
40-39-.
39-]
?;
38-Ecti/l m Noone 37-*
1 I3 124 36-1*
36
\\35 75 7 1 1 6i
- 67 ? I6-5 37 73 7
71 70 68 6
6 6
6 76 75 37 57 7
96 6
6 45-1'
- 1.
45-a Winter Flounder Winter Flounder 44Eggs 44-Eggs MARMAP lchthyoplankton Surveys MARMAP lchthyoplankton Surveys 4-61-cm Bongo Net: 11.505-mes...h 43 61-cm Bongo Net; 0.505-mm mesh 43-i 61c onoNt 055m ms 4
43-March; 1978 to 1987 4-April'1978 to 1987 41-41-i i
NnlooIo*
s Noneoo
oNosleo*o sNo2.r*tegs7 36-~
39IL 39-] K
-336 76 75 7'4 713 7*2 7'1 711 6'9 608 6'7 66 6t5 76 7'5 74 7'3 7'2 7'1 7'0 69 608 6'7 66 65 Figure 12, Distribution and abundance of winter flounder eggs collected during NEFSC MARMAP ichthyoplankton surveys from February to June, 1978-1987 [see Reid et al. (1999) for details].
Page 36 45 J -
i r
Winter Flounder 44-Eggs MARMAPlchthyoplankton Surveys 0
61-cm Bongo Net; 0.505-mm mesh May: 1978 to 1987 Numbherolt ows = 1085, witheggs= I9 *;*
j Winter Flounder Eggs MARMAP Ichthyoplunkton Surveys 61-cm Bongo Net: 0.505-mm mesh June; 1978 to 1987 Number f lows = 709. wilh eggs = 2 I 41-
- None 101e20 741 73 7'2 7!1 7()
659 66 5r7 66 65.
i
- None
- t01e36 75 7
73 2
71 70 6
66-67 6
Figure 12. cont'd.
Page 37 45+
I
-J I
L45 L
___I I
'Winter Flounder March (1977 to 1997)
Numbler otTnwss 1031. wsith la-vo 10 44MARMAP Ichthyoplankton Surveys4-61-cm Bongo Net: 0.5 05-mm mesh 44-o 414 440-42-42-4,
,+
- 1 7
"s' 3H-NumberofLarvae/ IO*'
N8.
Number of Larvae nI e m
Ilo<Ntm ItNone SOto
< 10 1 o 0
37*,
l(I o40 0 to 716 35--3 76 75 74 72 72 71 70 69 69 67 66 65 76 75 74 73 72 71 70 69 69 67 66 65 April (1977 Mto 1987)
Maymr97R (1977 tot 1987)
Numbe rTow 1 201, with avu= 66
~
Noohcr ofTows =1472, soohlave =60 43 43ý 421 42 40 40-I~-3-'
38-o Numbher of Larvae I lOiný9 Numbher of Larvae/lInI None
~
s'tNone 37 0
101 to 4113 10 to 71 36~
36-76 75 74 73 72 71 711 69 66 67 466 5
76 75 74 73 72 71 701 69 60 67 66 65 Figure 13. Distribution and abundance of winter flounder larvae collected during NEFSC MARMAP ichthyoplankton surveys from March to July, and September, 1977-1987 [see Reid et al. (1999) for details].
Page 38 45-L L.
1t i June (1977 to 1987)
Num er aft Tows = 893. with larvae = 16 44-423-40 37--
L 3641-35-;....;...
76 75 74 73 72 71 71 45-September (1977 to 1987)
N u m n er f T ow s, =
774. w ith larva e 1 44-43-"
421 41-'
411 39l~K
- t.
I I
I I
July (1977 to 1987)
Number of Tows
= 939. with larvae = I Number of Larvae / Im2 None I to< 10 101 o(25 Number of Larvae/ 1 0'm None 74 to 6 7i4 73.
7i2 71, 7i0 *9 69 67 6'6 65 6
69 66 67 66 N umber oif Larvae / I 0m2 None I to 5 74 73 72 71 70()
69 69 67 66 Figure 13. cont'd.
Page 39 Georges Bank 5
4 0
x 3 2
1-0 8
6 0
4 cto a)
E 2
0/)
0 1960 1965 1970 1975 1980 1985 1990 1995 2000 Year Commercial landings (mt)
Autumn survey index (kg)
Smoothed survey index (kg)
Gulf of Maine 3.5 3.0 2.5 0
2.0 or 1.5 to 1.0
-j 0.5 0.0 194 Comme.rcial landings (mt)
MA spring survey index (kg) 50 30 25 20 15 10
.5 0
01 at E
"0a)
-+
0 2000 1965 1970 1975 1980 1985 1990 1995 Year Southern New England - Middle Atlantic 14 12 10 x8 g6-C:
2 0-1960
/
-5 0
CO 0
2000 1965 1970 1975 1980 1985 1990 1995 Year Commercial landings (mt)
Spring survey index (kg)
Smoothed survey index (kg)
Figure 14. Commercial landings and. survey indices (from the NEFSC bottom trawl surveys) for winter flounder stocks from Georges Bank, the Gulf of Maine, and southern New England-Middle Atlantic Bight.