ML072060414
| ML072060414 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/01/1983 |
| From: | Benson N, Fay C, Neves R, Pardue G, Shanks L US Dept of Interior, Fish & Wildlife Service, US Dept of the Army, Corps of Engineers, Virginia Polytechnic Institute (VPI) & State Univ |
| To: | Office of Nuclear Reactor Regulation |
| Davis J NRR/DLR/REBB, 415-3835 | |
| Shared Package | |
| ML072060321 | List:
|
| References | |
| TR EL-82-4 FWS/OBS-82/11.10 | |
| Download: ML072060414 (24) | |
Text
Coastal Ecology Group Fish and Wildlife Service Waterways Experiment Station U.S. Department of the Interior U.S. Army Corps of Engineers
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FWS/OBS-82/11.10 TR EL-82-4 Ocotber 1993 Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic)
ATLANTIC SILVERSIDE by Clemon W. Fay, Richard J. Neves, and Garland B. Pardue Department of Fisheries and Wildlife Sciences Virginia Polytechnic Institute and State University Blacksburg, VA 24061 Project Manager Larry Shanks Project Officer Norman Benson National Coastal Ecosystems Team U.S. Fish and Wildlife Service 1010 Gause Boulevard Slidell, LA 70458 This study was conducted in cooperation with Coastal Ecology Group U.S. Army Corps of Engineers Waterways Experiment Station Performed for National Coastal Ecosystems Team Division of Biological Services Fish and Wildlife Service U.S. Department of the Interior Washington, DC 20240
CONVERSION FACTORS Metric to U.S. Customary Multiply To Obtain, millimeters (mm) 0.03937 inches centimeters (cm) 0.3937 inches meters (i) 3.281 feet kilometers (km) 0.6214 miles square meters (mL) 10.76 square feet square kilometers (kin2) 0.3861 square miles hectares (ha) 2.471 acres liters (1) 0.2642 gallons cubic meters (m3 ) 35.31 cubic feet cubic meters 0.0008110 acre-feet milligrams (mg) 0.00003527 ounces grams (gm) 0.03527 ounces kilograms (kg) 2.205 pounds metric tons (mt) 2205.0 pounds metric tons (mt) 1.102 short tons kilocalories (kcal) 3.968 BTU Celsius degrees 1.8(C6) + 32 Fahrenheit degrees U.S. Customary to Metric inches 25.40 mril I imeters inches 2.54 centimeters feet (ft) 0.3048 meters fathoms 1.829 meters miles (mi) 1.609 ki 1ometers nautical miles (nmi) 1.852 kilometers square feet (ft') 0.0929 square meters acres 0.4047 hectares square miles (mi 2
) 2.590 square kilometers gallons (gal) 3.785 liters cubic feet (ft 0.02831 cubic meters.
acre-feet 1233.0 cubic meters ounces (oz) 28.35 grams pounds (lb) 0.4536 kilograms short tons (ton) 0.9072 metric tons BTU 0.2520 kilocalories Fahrenheit degrees 0.5556(F° - 32) Celsius degrees
CONTENTS Page CONVERSION TABLE ............................ ................. i PREFACE. . ..................................................... iv ACKNOWLEDGMENTS . .. ................... ............... ......... v NOMENCLATURE/TAXONOMY/RANGE ..................... ............... 1 MORPHOLOGY/IDENTIFICATION AIDS. .............. ..................... I REASON FOR INCLUSION IN SERIES ..................... ............. 3 LIFE HISTORY ................. ..... ......................... 3 Reproductive Physiology/Strategy ............. .................... 3 Spawning-General ...... ........... ...................... 4 Spawning Periodicity .................................. 4 Spawning Behavior ................................................. 5 Dissolved Oxygen Depletion (Spawning) ...... . ..... ............ 5 Egs.......................................
Eggs 5 5
Yolk-Sac Larvae. 6.............................6 Larvae.................................................. 6 Juveniles/Adults . ... ..... . ... . ......... ................ 7 GROWTH CHARACTERISTICS... . . . . . . . . . . . . . ....... .......... 8 THE FISHERY .................... 9 Commercial and Recreational Fisheries. . ....... ............... 9 Population Dynamics .... ................... ....................... 9 ECOLOGICAL ROLE ..................... .................. ........ 9 Food Habits/Feeding Behavior ........ . .......... ......... I ..... 9 Predators ........................................ .......... 10 Competitors .......................... ................ ..... 10 Role as Estuarine Biomass Exporter ........... .... ............... 10 ENVIRONMENTAL REQUIREMENTS ............... ........................ 10 Temperature ..................... .............................. 10 Salinity ................ ................................ . I.11 LITERATURE CITED .................. ............................. 12 iii
PREFACE This species profile is one of a series on coastal aquatic organisms, principally fish, of sport, commercial, or ecological importance. The profiles are designed to provide coastal managers, engineers, and biologists with a brief comprehensive sketch of the biological characteristics and environmental require-ments of the species and to describe how populations of the species may be expected to react to environmental changes caused by coastal development. Each profile has sections on taxonomy, life history, ecological role, environmental requirements, and economic importance, if applicable. A three-ring binder is used for this series so that new profiles can be added as they are prepared.
This project is jointly planned and financed by the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service.
Suggestions or questions regarding this report should be directed to:
Information Transfer Specialist National Coastal Ecosystems Team U.S. Fish and Wildlife Service NASA-Slidell Computer Complex 1010 Gause Boulevard Slidell, LA 70458 or U.S. Army Engineer Waterways Experiment Station Attention: WESER Post Office Box 631 Vicksburg, MS 39180 This series should be referenced as follows:
U.S. Fish and Wildlife Service. 1983. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates. U.S. Fish and Wildlife Service, Division of Biological Services, FWS/OBS-82/11.
U.S. Army Corps of Engineers, TR EL-82-4.
This profile should be cited as follows:
Fay, C.W., R.J. Neves, and G.B. Pardue. 1983. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (Mid-Atlantic) -- Atlantic silverside. U.S. Fish and Wildlife Service, Division of Biological Services, FWS/OBS-82/11.10. U.S. Army Corps of Engineers, TR EL-82-4. 15 pp.
iv
ACKNOWLEDGMENTS We are grateful for the review by Dr. David Conover, State University of New York at Stony Brook, Long Island.
V
Figure 1. Atlantic silverside.
ATLANTIC SILVERSIDE NOMENCLATURE/TAXONOMY/RANGE Brunswick, Nova Scotia, and the Magdalen Islands (Gosline 1948),
south to Volusia County, Florida Scientific name . ... Menidia menidia (Leim and Scott 1966). Wide-Preferred comrion name . Atlantic sil- spread and abundant in coastal verside (Figure 1). waters and tributaries of the Other common names.. Spearing, sper- entire area (Massmann 1954; Rob-Iing, green smelt, sand smelt, white bins 1969) (see Figure 2 for a bait, capelin, shiner (Bigelow and map of the mid-Atlantic distribu-Schroeder 1953). tion of Atlantic silverside).
Class ................ .Osteichthyes Order. ...... . .Atheriniformes Family .... .......... .. Atherinidae MORPHOLOGY/IDENTIFICATION AIDS The following information was Geographical range: Atlantic coast of taken from summaries in Martin and North America, from just north of Drewry (1978), where a detailed 47 degrees north latitude, in New morphological description is available.
I
N.Y.
I, N.J.
i PHILADELPHIA ATLANTIC OCEAN MILES 0 50 100 0 50 100 KILOMETERS CHESAPEAKE BA Y
- Offshore distribution 0 W Area of high abundance in winter IARLE S Area of high abundance
,SoUND in andspring, fall summer,
/L. ' O'kCAPE HA TTERAS Figure 2. Mid-Atlantic distribution of the Atlantic silverside. The offshore distribution boundary is representative of the majority of Atlantic silverside populations; however, National Marine Fisheries Service (NMFS) trawl surveys have reported Atlantic silversides offshore to 180 km (112 mi) in spring/sum-mer and to 150 km (93 mi) in winter (Conover and Murawski 1982).
2
Dorsal spines 3-7 (mean 4.6), particularly -environmental require-dorsal rays 7-11 (mean 8.6), anal ments (Conover and Ross 1982).
spines 1, anal rays 19-29 (mean 23.6). Lateral line scales between pectoral insertion and caudal fin 34-47 LIFE HISTORY (mean 40.7).
Body elongate, slender, rounded Reproductive Physiology/Strategy to dorsally depressed. Head triangu-Atlantic silversides are hetero-lar, dorsally flattened; mouth terminal and slightly superior, maxillary not sexual; however, an. unusual mecha-extending to front of eye. Scales nism of sex determination in this cycloid with entire margins, well species has been identified. Adult imbricated. gender is apparently controlled by interaction of female parent genotype
.. Color: Dorsally translucent green with water temperature regime during to greenish-yellow; laterally silver, a specific and critical period of larval with well defined, longitudinal, metal- development (see LIFE HISTORY--Lar-lically lustered, silver-colored stripe, vae section) (Conover and Kynard edged above by dark line; ventrally 1981). Reproductive mode varies from white. Dorsal and caudal fin rays uni- polygamy (Middaugh et al. 1981) to formly spotted, and caudal fin usually extensive promiscuity (Conover 1982).
tinged with yellow.
Both sexes of the Atlantic silver-side mature by age 1. Although 2-year-old specimens have been reported (Bayliff 1950; Conover and REASON FOR INCLUSION IN SERIES R6ss 1982), apparently most adults die after completion of their first spawn-ing (perhaps because of physiological The Atlantic silverside is an exhaustion) (Conover and Ross 1982),
important forage fish (Merriman 1941; or are lost to other causes of mortal-Bayliff 1950; Bigelow and Schroeder ity before they reach age 2. In 1953), reaching high abundance in the Essex Bay, Massachusetts,. 2-year-shore-zone of salt marshes, estuaries old fish constituted 0.2% and 1.0%,
and tidal creeks. This species is often respectively, of the 1977 and 1978 the most ab.undant fish encountered in spawning populations. Both males and these areas (Mulkana 1966; Richards females were represented by and Castagna 1970; Briggs 1975; 2-year-old individuals (Conover and Anderjson et al. 1977; Hillman et al. Ross 1982). Females are larger and 1977).' heavier than males of the same age (Conover 1982), a fact that may be The importance of Atlantic silver- related to the unusual mechanism of
- sides as forage for such piscivores as sex determination discussed in the striped bass (Morone saxatilis), LIFE HISTORY -Larvae section.
Atlantic mackerel (Scomber scombrus),
and bluefish (Pomatomus saltatrix) has Little is known concerning fre-been well documented (Bayliff 1950.; quency of spawning within a season Bigelow and Schroeder 1953; Schaefer for an individual silverside. A fre-1970). Presumably then, the Atlantic quency of four or five times per silverside should be a key member of female per season was reported in the estuarine food web, but until Conover (1979). In laboratory studies recently, little study . has been of spawning activities of female Atlan-devoted to its life history, tic silversides in 85-1 aquaria, 3
individual females spawned up to 20 over a 3-year-period (Middaugh 1981).
separate times in a season (Conover Initiation of spawning is probably 1982). The applicability of this determined by water temperature, spawning frequency to field environ- photoperiod, or, both (Middaugh and ments is -unknown, since (1) ripe Lempesis 1976), in conjunction with females were placed in test tanks high tide and appropriate lunar phase individually, rather than in large during the spring months (Middaugh schools as in natural environments; 1981; Conover 1982).
(2) spawning periodicity of an indi-vidual female was every 1 to 3 days, Spawninq Periodicitv not coinciding with normal lunar cycles or observed natural spawning Menidia menidia is one of over 50 periodicity; and (3) no "tide-like" fish species known to have lunar-influences were applied in the labora- related spawning cycles (.Johannes 1978; tory tests. Conover 1982). Spawning occurs strictly during daylight hours in large Fecundity of Atlantic silversides schools, and coincides with high tide ranged from 4,725 to 13,525 total (Middaugh 1981). The first spawning eggs. The average number of eggs activity usually occurs at a new or actually spawned in a season was full moon in early spring, and is fol-4,500 to 5,000 per female. It was lowed by spawning peaks at approxi-noted that these eggs were probably mately 14- (Conover 1982) or 15-day released in four or five separate (Middaugh 1981) intervals. Some spawning events per female per year spawning activity was observed on (Conover 1979). A much lower fe- days other than those of new or full cundity estimate, from earlier studies, moon (Middaugh 1981), but up to 90t was an average of 500 eggs (Hilde- of the spawning within each 14- to brand 1922) and a range up to 1,400 15-day stratum occurred over 1-eggs (Kendall 1902). (Conover 1982) to 3-day (Middaugh 1981) periods. Some differences in Spawning-General spawning periodicity between South Carolina and Massachusetts populations Atlantic silversides spawn in the of, Atlantic silverside have been intertidal zone of nearly all major reported. Conover (1982) concluded estuaries and tributaries within, their that spawning periodicity in Massa-geographic range (Hildebrand 1922; chusetts was highly correlated to the Wang 1974). Spawning areas are sea- lunar phase, and that spawning inten-ward of locations used by Menidia sity was dependent on relative height beryllina (inland silverside), a closely of a given high tide. In contrast, related species (Smith 19.71). The Middaugh (1981) found that the great-major spawning season of Atlantic sil- est correlation in South Carolina pop-versides in the mid-Atlantic region ulations was between spawning perio-extends from late March through June dicity and the coincidental occurrence (Nichols 1908; Hildebrand 1922; Mid- of sunrise and high tide, approxi-daugh 1981). Ripe females have been mately every 15 days. Days of high collected through July in Massachu- tide at sunrise also coincided fairly setts (Kuntz and Radcliffe 1917; Wil- closely with new and full lunar phases liams and Shaw 1971) and in Chesa- during spring months. Regardless, peake Bay (Bayliff 1950; Rasin 1976), the periodicity-lunar phase correlation at water temperatures between 130 and was not as high as the periodicity-30*C (550 and 860F) (Middaugh and sunrise and high tide correlation in Lempesis 1976). Spawning began at the South Carolina population. Addi-temperatures between .160 and 200 C tionally, relative height of the high (610 and 680 F) in South Carolina, tide was not correlated with spawning 4
intensity (Middaugh 1981). During density gradients of spawning fish spring high tides, the greatest within a school. In an unusually spawning intensity was observed at intense spawning event on 30 April the slack (Middaugh 1981) or ebbing 1976, dissolved oxygen dropped from (Conover 1982) stages. It is apparent 6 mg/I to 0.7 mg/I in the center of from studies of Atlantic silverside the spawning mass.
spawning periodicity that specific.
mechanisms and adaptive significance An interesting consequence of of lunar-related spawning cycles are this dissolved oxygen depletion was poorly understood (Conover 1982). reported (Middaugh 1981). Predators such as small bluefish and spotted Spawning Behavior seatrout (Cynoscion nebulosus), sur-rounding spawning schools of Atlantic Middaugh et al. (1981) described. silversides, were unable to penetrate spawning behavior of Atlantic silver- past the 4.0 mg/I and 2.5 mg/I dis-sides in South Carolina. One-half to 1 solved oxygen isopleths, respectively.
hour prior to a spawn, a single large This apparently limited or prevented school or several smaller schools of predation on the heaviest concentra-adults appeared 10 to 30 m (33 to 98 tions of Atlantic silversides during the ft) offshore, adjacent to the eventual time of peak spawning (Middaugh spawning site. Schools swam parallel 1981). The oxygen depletion in combi-to shore, gradually moving shoreward nation with the energy drain, associ-with the flood stage until the leading ated with spawning appeared to affect edge of the school was 2 to 3 m (6 to the spent silversides (Middaugh 1981).
10 ft) from shore. Positions in relation Spent fish from intense spawning to shore and swimming speed of the events were observed offshore from school were maintained until just spawning beds in tight but nonschool-before peak high tide, when several ing aggregations, and appeared to be individuals moved suddenly into stuporous and in a state of physiolog-flooded shoreline vegetation, followed ical recovery. These stuporous aggre-by the remainder of the spawning gations could be approached by man, school. Eggs were released as a and presumably by predators, with female crossed the axis of a potential relative ease.
attachment substrate such as a cord-grass plant. One to several males fol- Eggs lowed closely and deposited milt. Sev-eral variations on this general Eggs of the Atlantic silverside behavioral pattern were described in generally range from 0.9 to 1.2 mm 1 in Middaugh et al. (1981) and Conover diameter (Wang 1974; Middaugh 1981),
(1982), including spawning in aban- though diameters up to 1.5 mm have doned fiddler crab (Uca pugilator) been reported (Tracy 1910; Leim and burrows. Scott 1966). Eggs are transparent, yellow to green, and have 5 to 12 Dissolved Oxygen Depletion (Spawning) large oil globules and numerous small globules (Kuntz - and Radcliffe 1917; Middaugh (1981) and Middaugh et Hildebrand 1922). Eggs are demersal, al. (1981) found that extremely high adhesive, and found in shallow waters spawning densities, commonly of estuarine intertidal zones (Kuntz observed during peak Atlantic silver- and Radcliffe 1917; Hildebrand 1922; side spawning episodes, temporarily Middaugh 1981).
depleted dissolved oxygen concentra-tions in the immediate area of the most Substrates for egg attachment are intense spawning activity. Dissolved submerged vegetation (Bayliff 1950),
oxygen isopleths coincided closely with particularly eelgrass (Middaugh 1981),
'25.4 mm = 1 inch.
5
cordgrass (Middaugh et al. 1981), and viability and depth of embryo location filamentous algae (Conover 1982). was not indicated.
Sand (Wang 1974) and beach trash.
(Nichols 1908) may also harbor Yolk-Sac Larvae attached" eggs. Studies in Salem Har-bor, Massachusetts, indicated that egg Atlantic silverside yolk-sac larvae attachment substrates there were more range from 3.8 to 5.0 mm total length specific than those described for other (TL) at hatching (Wang 1974). The silverside populations. Only algal mats proportion of the original yolk-sac of the filamentous brown algae Pilay- remaining at hatching depends on ella littoralis and Entermorpha spp. incubation temperature; a defined were used, even though these algae yolk-sac is absent when eggs are were growing among various aquatic incubated at 250 C (770 F) or less vascular plants such as Spartina (Bayliff 1950; Austin et al. 1975).
alterniflora (Conover 1982). Remaining yolk is absorbed 2 (Mid-daugh and Lempesis 1976) to 5 (Rubi-Egg attachment is reinforced by noff 1958) days after hatching. Yolk-several filaments (Hildebrand 1922; sac larvae are transparent with Middaugh 1981; Conover 1982) origi- pigmented eyes at hatching (Hildebrand nating from a specific area of the 1922; Middaugh and Lempesis 1976).
chorion (Kuntz and Radcliffe 1917; Middaugh (1981) found that larval Wang 1974), which uncoil upon ovipo- hatching occurred primarily at night sition (Ryder 1883; Hildebrand 1922). during high tides, and suggested that Filaments are usually from five (Mid- decreased predation may be a benefit daugh 1981) to eight (Ryder 1883) of nocturnal emergence.
times the egg diameter in length.
Eggs may also adhere to each other in Larvae clusters (Hildebrand 1922; Leim and Scott 1966). Atlantic silverside larvae range from 5.5 to 15.0 mm TL (Wang 1974).
Incubation time for Atlantic sil- Both yolk-sac larvae, and larvae have verside eggs was 3 days at 30*C (860 a notably forward anus, rarely far-F), 5 days at 25*C (77*F), 10 days at ther behind the snout than one-fourth 200C (68°F), 15 days at 18'C (64°F), of the total larval length (Martin and and 27 days at 15'C (59"F) (Costello Drewry 1978). Size at transformation et al. .1957; Austin et al. 1975). An to the juvenile stage is not estab-equation for predicting incubation time lished, but transformation occurs from water temperature, calculated before 20 mm TL (Wang 1974) and is from data in Austin et al. (1975) by complete when the anus has migrated Martin and Drewry.(1978), is: back along the ventral surface of the body to the approximate midpoint log(t) = 2.2672 - 0.0623(T) (Hildebrand 1922).
where t = time in days and T = incu- An unusual method of sex deter-bation temperature in degrees C. mination during the larval stage of Atlantic silversides was demonstrated Middaugh (1981) found that maxi- in a series of laboratory experiments mum egg abundance in South Carolina by Conover and Kynard (1981). Lar-waters occurred at depths of 1.6 to vae subjected to a "cold fluctuating" 2.2 m (5.3 to 7.2 ft) below the mean temperature regime similar to tempera-low water (low tide) line. Embryo tures experienced by larvae in May, viability was also highest in this between 110 and 191C (52' and 66*F),
depth range, though a statistically produced more females than males. . In significant correlation between embryo contrast, a "warm fluctuating" 6
temperature regime similar to tempera- Smaller juveniles select habitats over tures experienced by larvae in July, vegetated substrates more often than between 170 and 250C (630 and 77 0 F), the sand and gravel substrates produced significantly more males than selected by larger juveniles and adults females. Further, it was determined (Briggs and O'Conner 1971).
that the mechanism of sex determina-tion was not by selective egg or larval Juvenile and adult Atlantic sil-mortality, but rather the temperature versides inhabit intertidal creeks, regime experienced by larvae during a marshes, and shore zones of bays and critical period, which was between 32 estuaries in spring, summer, and fall and 46 days after hatching. The water (Hildebrand and Schroeder 1928; temperature regime experienced by Bigelow and Schroeder 1953). Tempo-larvae at that stage of development ral variation in local abundance, determined whether mostly males or probably due in part to fish move-females developed (Conover and ments in relation to tidal patterns, Kynard 1981). These laboratory find- has been reported (Merriman 1947; ings were corroborated by examination Shenker and Dean 1979; Conover of sex ratios in natural populations 1982; Conover and Ross 1982). Dur-(Essex Bay, Massachusetts) over time ing spring, summer, and fall, Atlantic (Conover 1982). silversides have often been reported, as the most abundant species in marsh Dovel (1971) reported that Atlan- and estuarine habitats (Pearcy and tic silverside larvae were present Richards 1962; Mulkana 1966; Richards throughout low salinity areas of upper and Castagna 1970; Briggs 1975; Chesapeake Bay, from April through Anderson et al. 1977), yet they may December. Larvae were most abundant be entirely absent from the same areas in surface waters (< 3 m, < 10 ft) and during winter (Bayliff 1950; Hoff and at salinities of 8 or 9 ppt. Some lar- Ibara 1977; Conover 1982; Conover vae were found in waters where salin- and Ross 1982).
ities ranged from 1 to 14 ppt and water temperatures from 12' to 300C Geographic variability exists .with (540 to 86%F). In the Mystic River the winter ecology and habitat of Estuary, Connecticut, Atlantic silver- adult Atlantic silversides (Conover side larvae were found primarily in and. Murawski 1982). In populations upper estuarine zones and marshes, from Chesapeake Bay northward, where the salinity profile ranged from Atlantic silversides are rare or absent 2 ppt at the surface to 14 ppt at 2 m from shore zones or shallow waters in (6 ft) depth. All larvae were collected midwinter (Bayliff 1950; Hoff and in May and June and ranged from 5.2 Ibara 1977; Conover and Ross 1982).
to 7.5 mm TL (Pearcy and Richards. Richards and Castagna - (1970) 1962). reported that adult Atlantic silversides were captured in midwinter with bot-Juveniles/Adults tom trawls in deepwater areas of Chesapeake Bay and estuarine chan-Juvenile Atlantic silversides nels along eastern Virginia. Winter range in size from about 20 mm TL catches of adults out to 15 km (913 (Wang 1974) *to approximately 91 mm mi) (Clark et al. 1969; Fahay 1975)
TL (males) or-98 mm TL (females) and 170 km (105.6 mi) (Conover and (Leim and Scott 1966; Conover and Murawski 1982) offshore have been Ross 1982). The juvenile stage lasts reported. In South Carolina tidal from the completion of anal vent creeks, however, adults were present migration along the ventral midline in high abundance throughout winter (Martin and Drewry 1978) to cessation (Cain and Dean 1976; Shenker and of growth in late fall (Conover 1982). Dean 1979).
7
National Marine Fisheries Service GROWTH CHARACTERISTICS (NMFS) survey data, collected with bottom trawls from Cape Cod, Massa-chusetts, to Cape Hatteras, North Growth of young-of-the-year Carolina, was summarized by Conover Atlantic silversides from hatching to and Murawski (1982). From 1972 to mid-autumn was 10-15 mm/month in 1979 (data pooled), percent frequency Long Island Sound (Austin et al.
of occurrence (number of stations 1973), 7-14 mm/month in a Rhode captured divided by number of sta- Island estuary (Mulkana 1966), and 20 tions surveyed) of Atlantic silversides mm/month in Essex Bay, Massachu-in depth strata, between 5 and 27 m setts (Conover and Ross 1982).
(16 and 89 ft), peaked in January Young-of-the-year males attained 91.5 (34.3%). Atlantic silversides also mm and 3.9 g by November in Essex occurred in March (21.4%), April Bay,, and females attained 98.0 mm (9.6'o), and November (4.9%). Depth and 4.8 g (Conover and Ross 1982).
strata from 5 to 27 m were not sam- Growth of Atlantic silversides virtually pled in February. At depth strata ceases between November and March, between 27 and 366 m (89 and 1,200 at least in areas where winter offshore ft) (1963 to 1979, data pooled), per- migrations occur (Bayliff 1950; cent frequency of occurrence peaked Bigelow and Schroeder 1953; Conover in F'ebruary (11.2%), and dropped off 1982; Conover and Ross 1982).
in March (4.3%) and April (1.5%). The majority (86%) of all Atlantic silver- Condition factor of young-of-the-sides captured in the' NMFS surveys year Atlantic silversides in Essex were at depths less than 50 m (164 ft) Bay, Massachusetts, dropped signifi-and water temperatures between 2' cantly. between September and Novem-and 6 0 C (360 and 430F) (Conover and ber for the large 1976 year class, Murawski 1982). but not for the less abundant. 1977 year class (Conover and Ross 1982).
Comparison of winter catch rates For both year classes, the condition during different times of the day factor r-mained stable through winter, indicated that overwintering Atlantic increasing in April and May of the silversides may migrate vertically in following spring. Conover and Ross the water column during twilight peri- (1982) suggested that the 1976 year ods. Consistently higher numbers of class may haVe exceeded the carrying silversides were captured during the capacity of the Essex Bay nursery day with bottom trawls than at night area, resulting in the observed in the same overwintering areas (Con- reduction in condition during late over and Murawski 1982). stages of the growing season (October and November).
Biochemical characteristics (through electrophoresis) of Atlantic G rowth rates of age 11 male silverside stocks (Morgan and Ulanow- Atlantic silversides in Essex Bay icz 1976) and the genus Menidia averaged 5.8 mm/month and 1.1 (Johnson 1975) have been described. g/month over the period 6 May to 5 The applicability of such information November. Females grew 5.5 mm/month for separation of stocks and apparent and 1.4 g/month over the same subspecies of Menidia menidia (M. m. period. By 5 November, mean lengths menidia, southern subspecies, and M. and weights of female Atlantic silver-
- m. notata, northern subspecies) is sides exceeded values for males by 10 discussed in Morgan and Ulanowicz mm and 2.9 g (Conover and Ross (1976). 1982).
8
THE FISHERY against larger fish, and total mortality was negatively related to mean size and condition of the juvenile year Commercial and. Recreational Fisheries class prior to winter migration. They suggested that, since densities of Commercial or recreational fisher- adults returning the following spring ies *for Atlantic, silversides are not were similar regardless of the fall documented. The authors have population size, a density compensa-observed a small and scattered com- tory mechanism of overwintering mor-mercial bait fishery for Atlantic sil- tality may occur in Atlantic silverside versides using minnow traps or small populations.
seines. Such localized bait fisheries probably have little if any impact on Conover (1982) demonstrated that Atlantic silverside populations. sex ratios of Atlantic silversides in Population Dynamics Essex Bay, Massachusetts, fluctuated seasonally, partly because of the unusual mechanism of sex determina-In general, the Atlantic silverside tion described for this species (Con-is a short-lived species. Two-year-old over and Kynard 1981) (see LIFE fish have been reported (Bayliff 1950; ,HISTORY-- Larvae section). Sex rat-Conover and Ross 1982), but the ios in July and August consistently majority of estuarine populations of favored females, while sex ratios in Atlantic silversides in spring, sum- September (year-class recruitment mer, and fall are juveniles (age 0+) complete), October, and November and age 1 adults (Conover and favored males. Sex. ratios on the Murawski 1982). spawning grounds the following spring either favored, females (1978) or were Abundance of the 1977 year class not significantly different from 1:1 of silverside juveniles in Essex Bay, (1976, 1977).
Massachusetts, in late October and early November .ý(data pooled) - (95 was fi-estimated at 1.88 1.16/m (95 conf-dence limits). Mean biomass of juve-niles peaked in late October and early November at 7.8 +/- 2.8 9/m 2 Adult ECOLOGICAL ROLE densities on spawning grounds the next spring (1978) were estimated at 0.009 +/- 0:002/m2 , indicating a total Food Habits/Feeding Behavior overwintering mortality rate of 99%
(Conover and Ross 1982). Conover Information about larval food and Ross (1982) examined Atlantic sil- habits, feeding behavior, and daily
- verside mortality estimates from other ration is not available. Juvenile and coastal areas of Massachusetts and adult Atlantic silversides are oppor-found that overwintering mortality tunistic omnivores. Food items con-averaged 97%0 north of Cape Cod and sumed include copepods, mysids, 88% south and west of Cape Cod. Sim- amphipods, cladocerans, fish eggs, ilarly high overwintering mortality was squid, worms, molluscan larvae, reported by Warfel and Merriman insects, algae, diatoms, and detritus (1944) in Connecticut, Bayliff (1950) (Bigelow and Schroeder 1953; Leim in Chesapeake Bay, and Austin et al. and Scott 1966; Thomson et al. 1971).
(1973) in New York.
Atlantic silversides feed. in large Conover and Ross (1982) also schools, often following the tidal ebb found that overwintering mortality of and flow along feeding areas. Common Atlantic silversides was selective feeding areas include gravel and sand 9
bars, open beaches, tidal creeks, silversides migrate to offshore waters river mouths and flooded zones of during late fall. Numbers of age I marsh vegetation (Bayliff 1950; Bige- adults returning the following spring low and Schroeder 1953). Information indicated very high overwintering about feeding periodicity is not avail- mortality (99%). Few if any age I fish able. make it to age 2; most age 1 fish die after spawning or during their second In laboratory tests, unfed larvae winter of life. This essentially annual and larvae fed for the first time on life cycle, with high mortality off-day 4 all died by day 6. Survival of shore, suggests that Atlantic silver-larvae fed at the end of day 2 varied sides are important exporters of sec-with salinity. At 20 ppt, all larvae ondary production and biomass from were dead by day 8, while at 30 ppt, marsh and estuarine systems to off-40' survived through day 14 (Mid- shore areas (Conover and Murawski duagh and Lempesis 1976). 1982).
Predators ENVIRONMENTAL REQUIREMENTS Atlantic silversides are important forage for such gamefish as striped bass, Atlantic mackerel, and bluefish. Temperature (Bayliff 1950; Bigelow and Schroeder 1953; Schaefer 1970). Other fish Eggs of Atlantic silverside toler-species, egrets, terns, gulls, cormo- ated water temperatures as low as 15' rants, and blue crabs (Callinectes C (590 F), but larvae that hatched sapidus) also prey on spawning died within 24 hr unless warmer water schools of Atlantic silversides (Mid- was located (Austin et al. 1975).
daugh 1981).. Blue crabs, ruddy turn- Temperatures as high as 30'C (860F) stones (Arenaria interpres morinella), were also tolerated by eggs. Visible semipalmated sandpipers (Ereunetes yolk was present upon hatching in 20%
pusillus), and in particular, mummi- of the larvae reared at 30'C, but was chogs (Fundulus heteroclitus), may absent in larvae hatched at 25'C (770 prey on eggs and larvae of Atlantic F) or less (Austin et al. 1975).
silversides (Middaugh 1981; Conover Optimum temperatures for hatching of 1982).
- eggs have not been determined.
Competitors Thermal shock of an 8'C (14'F) increase produced no mortality of Definitive studies of competitive Atlantic silverside larvae reared at 170 interactions between Atlantic silver- and 20'C (63' and 68°F), 19' mortal-sides and other species are lacking. ity at 25'C (77'F), and 11% mortality Some competition with the closely at 30'C (86'F) Thermal shock of a related inland silverside (Menidia 14' C (25' F) increase produced 3% .
beryllina) may occur, although these mortality of larvae reared at 17'C (630 two atherinids appear to be spatially F), 0% at 20-C (680F), and 1009% at256 separated in many areas. The Atlantic and 300 C (770 and 86' F) (Austin et silverside generally selects habitats al. 1975). Austin et al. (1975) con-more seaward than those of the inland cluded that, since Atlantic silverside silverside (Robbins 1969). larvae would be present in Long Island Sound at seasonal temperatures Role as Estuarine Biomass Exporter between 15' and 20'C (59' and 68'F),
the larval population would experience Conover and Murawski (1982) minimal stress from nuclear power-demonstrated that age 0* Atlantic plant development on Long Island.
10
Juvenile Atlantic silversides tol- died by 48 hr) were determined by erated water temperatures between 3T Hoff and Westman (1966) for a range and 31'C (370 and88 0 F),and preferred of acclimation temperatures. The a temperature range of 18' "to 250 lower TLM values for acclimation C (640 to 77°F) in upper Chesapeake temperatures of 70, 14", 21', and 280 Bay, during summer and fall (Dovel C (450, 570, 700, and 82°F)were 1.5' 1971). Juveniles and adults accli- 20, 50, and 9.5'C (35', 36", 41',
mated to 6VC (43'F) and 8'C (46'F), -aod 49'F), respectively. Upper TLM however, preferred water tempera- values for the same four acclimation tures of 150C (59' F) (Meldrim and temperatures were 220, 260, 300, and Gift 1971). In general, avoidance 320C (720, 790, 860, and 90'F),
behavior of juveniles and adults was respectively (Hoff and Westman 1966).
observed when test temperatures were 110 to 14°C (200 to 25'F) higher than Salinity the acclimation temperature' (Meldrim and Gift 1971). Pearce (1969) reported In laborat6ry tests, hatching was an upper lethal temperature of 32.00C delayed 18 hr at 20 ppt salinity and (900 F) for Atlantic silversides col- 42 hr at 10 ppt, compared to hatching lected from the Cape Cod Canal, Mas- time at 30 ppt (incubation temperature sachusetts. Critical thermal maxima was 21.1 0C or 70 0 F). Percentage (defined as the temperature at which hatch was also reduced at salinities opercular movements ceased for 30 below 30 ppt, and optimum salinity for seconds) for Atlantic silversides col- hatching was 30 ppt. Survival of lar-lected from the Patuxent River, vae through 14 days was approxi-Maryland, were 30.5'C (87 0 F) and mately 77%0 at 30 ppt compared to only 33.80C (93'F) for acclimation tempera- 23% at 20 ppt. Growth rate of larvae tures of 50C (41'F) and 15'C (599F), through day 14 was lower at 20 ppt respectively (Hall et al. 1982). compared to 30 ppt (Middaugh and Atlantic silversides exposed to three Lempesis 1976). Juvenile and adult different fluctuating temperature Atlantic silversides tolerated salinities regimes, between 5 'C and 15 0 C, from freshwater (Tagatz and Dudley exhibited critical thermal maxima 1961; Tagatz 1967) to 37.8 ppt intermediate to the above values (Hall (Tagatz and Dudley 1961). Juveniles et al. 1982). Lower and upper 48-hr were captured from upper Chesapeake median tolerance limits (TLM, the Bay in salinities from 1 to 14 ppt, but temperature at which 50%0 of test fish preferred 7 to 8 ppt (Dovel 1971).
11
LITERATURE CITED Anderson, W. D., J. K. Dias, D. M. Clark, J., W. G. Smith, A. W.
Cupka, and N. A. Chamerlain. Kendall, Jr., and M. P. Fahay.
1977. The macrofauna of the 1969. Studies of estuarine surf zone off Folly Beach, South dependence of Atlantic coastal Carolina. NOAA Tech. Rep. fishes. U. S. Bur. Sport Fish.
NMFS SSRF-704. 23 pp. Wildl. Tech. Pap. 28. 132 pp.
Austin, H. M., J. Dickinson, and C. Conover, D. 0. 1979. Density, R. Hickey. 1973. An ecological growth, production, and fecun-study of the ichthyofauna at the dity of the Atlantic silverside, Northport Power Station, Long Menidia menidia, in a central New Island, New York. Publ. Long England estuary. M.S. Thesis.
Island Lighting Co., Hicksville, University of Massachusetts, N. Y. 248 pp. Amherst. 59 pp.
Austin, H. M., A. D. Sosnow, and C. Conover, D. 0. 1982. Seasonal migra-R. Hickey. 1975. The effects of tion, reproductive strategy, and temperature on the development environmental sex determination, and survival of the eggs and lar- and its adaptive significance in vae of the Atlantic silverside. the Atlantic silverside. Ph.D.
Trans. Am. Fish. Soc. 104: Thesis. University of Massachu-762-765. setts, Amherst. 109 pp.
Bayliff, W. H. 1950. The life history Conover, D. 0., and B. E. Kynard.
of the silverside, Menidia meni- 1981. Environmental sex determi-dia. Chesapeake Biol. Lab. Publ. nation: interaction of tempera-
- 90. 27 pp. ture and genotype in a fish. Sci-ence 213: 577-579.
Bigelow, H. B., and W. C. Schroe-der. 1953. Fishes of the Gulf of Conover, D. 0., and S. A. Murawski.
Maine. U. S. Fish Wildl. Serv. 1982. Offshore winter migration Fish. Bull. 53. 577 pp. of the Atlantic silverside. U.S.
NatI. Mar. Fish. Serv. Fish. Bull.
Briggs, P. T. 1975. Shore-zone fishes 80: 145-150.
of the vicinity of Fire Island Inlet, Great South Bay, New Conover, D. 0., and M. R. Ross.
York. N. Y. Fish Game J. 22:1-7. 1982. Patterns in seasonal abun-dance, growth, and biomass of Briggs, P. T., and J. S. O'Conner. the Atlantic silverside in a New 1971. Comparison of shore-zone England estuary. Estuaries 5:
fishes over naturally vegetated 275-286.
and sand-filled bottoms in Great South Bay. N. Y. Fish Game J. Costello, D. P., M. E. Davidson, and 18: 15-41. A. Eggers. 1957. Methods for obtaining and handling marine Cain, R. L., and J. M. Dean. 1976. eggs and embryos. Mar. Biol.
Annual occurrence, abundance Lab., Woods Hole, Mass. 247 pp.
and diversity of fish in a South Carolina intertidal creek. Mar. Dovel, W. L. 1971. Fish eggs and lar-Biol. 36: 370-379. vae of the upper Chesapeake Bay. Univ. Md. Nat. Resour.
12
Inst. Spec. Rep. 4. 71 pp. of three species of marine fishes.
J. Mar. Res. 24(2): 131-139.
Fahay, M. P. 1975. An annotated list of larval and juvenile fishes cap- Johannes, R. E. 1978. Reproductive tured with surface-towed meter strategies of coastal marine fishes nets in the South Atlantic Bight in the tropics. Environ. Biol.
during four RV Dolphin cruises Fishes 3: 65-84.
between May, 1967 and February, 1973. NOAA Tech. Rep. NMFS Johnson, M. S. 1975. Biochemical sys-SSRF-685. 39 pp.
tematics of the Atherinid genus Menidia. Copeia 1975: 662-691.
Gosline, W. A. 1948. Speciation in the fishes of the genus Menidia. Evo-lution 2: 306-313. Kendall, W. C. 1902. Notes on the silversides of the genus Menidia Hall, L. W., Jr., D. T. Burton, and of the east coast of the United P. R. Abell. 1982. Thermal States, with descriptions of two response of Atlantic silversides new subspecies. Rep. U. S.
(Menidia menidia) acclimated to Fish. Comm. (1901): 241-267.
constant and asymmetric fluctuat-ing temperatures. Arch. Hydro- Kuntz, A., and L. Radcliffe. 1917.
biol. 94: 318-325. Notes on the embryology and lar-val development of twelve teleos-Hildebrand, S. F. 1922. Notes on tean fishes. U. S. Bur. Fish.
habits and development of eggs Bull. 34: 407-429.
and larvae of the silversides, Menidia menidia and M. beryllina. Leim, A. H., and W. B. Scott. 1966.
U. S. Bur. Fish. Bull. 38: Fishes of the Atlantic coast of 113-1 20. Canada. Fish. Res. Board Can.
Bull. 155: 1-485.
Hildebrand, S. F., and W. C.
Schroeder. 1928. Fishes of Ches- Martin, F. D., and G. E. Drewry.
apeake Bay. U. S. Bur. Fish. 1978. Development of fishes of Bull. 43. 388 pp. the mid-Atlantic Bight, Volume VI. U. S. Fish Wildl. Serv. Biol.
Hillman, R. E., N. W. Davis, and J. Serv. Program FWS/OBS-78/12.
Wennemer. 1977. Abundance, 416 pp.
diversity, and stability in shore-zone fish communities in an area of Long Island Sound Massmann, W. H. 1954. Marine fishes affected by the thermal discharge in fresh and brackish waters of of a nuclear power station. Virginia rivers. Ecology 35:
Estuarine Coastal Mar. Sci. 5: 75-78.
355-381.
Meldrim, J. W., and J. J' Gift. 1971.
Hoff, J. G., and R. M. Ibara. 1977. Temperature preference, avoid-Factors affecting the seasonal ance and shock experiments with abundance, composition and di- estuarine fishes. Ichthyol. Assoc.
versity of fishes in a southeastern Bull. 7. 75 pp.
New England estuary. Estuarine Coastal Mar. Sci. 5: 665-678. Merriman, D. 1941. Studies on striped bass of the Atlantic coast. U. S.
Hoff, J. G., and J. R. Westman. Fish Wildl. Serv. Fish. Bull. 50:
1966. The temperature tolerances 1-77.
13
Merriman, D. 1947. Notes on the Richards, C. E., and M. Castagna.
midsummer ichthyofauna of a 1970. Marine fishes of Virginia's Connecticut beach at different eastern shore (inlet and marsh, tide levels. Copeia 1947: 281-286. seaside waters). Chesapeake Sci.
11: 235-248.
Middaugh, D. P. 1981. Reproductive ecology and spawning periodicity Robbins, T. W. 1969. A systematic of the Atlantic silverside. Copeia study of the silversides. Ph.D.
1981: 766-776. Thesis. Cornell University, Ithaca, N. Y. 281 pp.
Middaugh, D. P., and P. W. Lempe-sis. 1976. Laboratory spawning Rubinoff, I. 1958. Raising the Atheri-and rearing of a marine fish, the nid fish, Menidia menidia, in the silverside Menidia menidia meni- laboratory. Copeia 1958: 146-147.
dia. Mar. Biol. 35: 295-300.
Ryder, J. A. 1883. On the thread Middaugh, D. P., G. I. Scott, and J. bearing eggs of the silversides.
M. Dean. 1981. Reproductive U. S. Fish. Comm. Bull. 3:
behavior of the Atlantic silver- 193-196.
side. Environ. Biol. Fishes 6:
269-276. Schaefer, R. H. 1970. Feeding habits of striped bass from the surf Morgan, R. P., II, and N. I. Ulanow- waters of Long Island. N. Y.
icz. 1976. The frequency of mus- Fish Game J. 17: 1-17.
cle protein polymorphism in Meni-dia menidia along the Atlantic Shenker, J. M., and J. M. Dean.
coast. Copeia 1976: 356-360. 1979. The utilization of an inter-tidal salt marsh creek by larval Mulkana, M. S. 1966. The growth and and juvenile fishes: abundance, feeding habits of juvenile fishes diversity and temporal variation.
in two Rhode Island estuaries. Estuaries 2(3): 154-163.
Gulf Res. Rep. 2: 97-168.
Smith, B. A. 1971. An ecological Nichols, J. T. 1908. A note on the study of the Delaware River in silverside. Am. Nat. 42: 731. the vicinity of Artificial Island.
Part V of The fish of four low-Pearce, J. B. 1969. Thermal addition salinity tidal tributaries of the and the benthos, Cape Cod Delaware River Estuary.
Canal. Chesapeake Sci. 10: Ichthyol. Assoc. Rep. Publ.
227-233. Serv. Electric and Gas Co.,
Ithaca, N. Y. 291 pp.
Pearcy, W. G., and S. W. Richards.
1962. Distribution and ecology of Tagatz, M. E. 1967. Fishes of the St.
fishes of the Mystic River Estu- Johns River, Florida. J. Fla.
ary, Connecticut. Ecology 43: Acad. Sci. 30(1): 25-50.
248-259.
Tagatz, M. E., and D. L. Dudley.
Rasin, V. J. 1976. Spawning and lar- 1961. Seasonal occurrence of val fish in the Potomac Estuary. marine fishes in four shore habi-Pages 95-99 in The Potomac Estu- tats near Beaufort, North Caro-ary, trends and options. Proc. lina, 1957-1960. U. S. Fish Wildl.
Symp. Md. Dep. Nat. Resour., Serv. Spec. Sci. Rep. Fish. 390.
1975, Alexandria, Va. 19 pp.
14
Thomson, K. S., W. H. Weed III, early developmental stages of and A. G. Taruski. 1971. Salt- fishes of the Potomac River Estu-water fishes of Connecticut. ary. Md. Dep. Nat. Resour.
Conn. State Geol. Hist. Surv. Power' Plant Siting Program.
Bull. 105. 165 pp. PPSP-MP-13. 282 pp.
Tracy, H. C. 1910. Annotated list of Warfel, H. E., and D. Merriman.
the fishes known to inhabit the 1944. Studies on the marine waters of Rhode Island. Annu. resources of south New England.
Rep. R. I. Comm. Inland Fish. Bull. Bingham Oceanogr. Collect.
40: 35-176. Yale Univ. 9: 1-91.
Wang, J. C. S. 1974. Atherinidae--- Williams, M. M., and E. Shaw. 1971.
silversides. Pages 143-151 in A. Modifiability of schooling behavior J. Lippson and R. L. Moran, in fishes: the role of early expe-eds. Manual for identification of rience. Am. Mus. Novit. 2448:
1-19.
15
50272-101 REPORT DOCUMENTATION REPORT
_. NO. 2. 3. Recpient's Accession No.
PAGE FWS/OBS-82/1 .10* _
- 4. Title and Subtitle 5. Reort 6ao,*tober ite 98 1983 Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic) -- Atlantic 6.
Silverside
- 7. Author(s) S. Pedor--ing Organizationi Riept. N10.
Clemon W. Fay, Richard J. Neves, Garland B. Pardue
- 9. Performing Organization Name and Address 10. Project/T..si/Work Unit No.
Department of Fisheries and Wildlife Sciences Virginia Polytechnic Institute and State University 11. Contract(C) or Grant(G) No.
Blacksburg, VA 24061 (C)
(G) 1Z. Sponsoring Organization Name and Address 13. Type of Report & Period Covered National Coastal Ecosystems Team U.S. Army Corps of Engineers Fish and Wildlife Service Waterways Experiment Station U.S. Department of the Interior P.O. Box 631 14.
Washington, DC 20240 Vicksburg, MS 39180
- 15. Supplementary Notes
- U.S. Army Corps of Engineers report No. TR EL-82-4
. 16. Abstract (Limit: 200 -ords)
Species profiles are literature summaries of the taxonomy, morphology, range, life history, and environmental requirements of coastal aquatic species. They are prepared to assist in environmental impact assessment. The Atlantic silverside (Menidia menidia) is an important link in estuarine food webs as an opportunistic omnivore and as forage for large piscivores such as striped bass (Morone saxatilis) and bluefish (Pomatomus saltatrix). Many times the Atlantic silverside is the most abundant fish species encountered in estuaries and tribu-taries. They mature at age I and spawn in the intertidal zone of estuaries from March to June in the mid-Atlantic region. Few 2-year-old fish are ever encountered, so the Atlantic silverside is basically a short-lived species. Most spawning occurs at high tide during new or full moon phases. Eggs are adhesive and are found attached to submerged vegetation.
Larvae, juveniles, and adults generally inhabit similar areas. Sex is determined in larval development 32 to 46 days after hatching, and is a function of parental genotype and water temperature regime during the critical period. Fisheries for this species are not documen-ted. Eggs can tolerate water temperatures between 15' and 30'C, and larvae need temperature above 150 C for survival. Larvae tolerate relatively acute temperature increases. Upper lethal temperatures for juveniles and adults range from 30.50 to 33.8 0 C, depending on acclimation temperature. Salinities of 20 ppt or lower significantly delay hatching and affect larval survival. Juveniles and adults tolerate the full range of naturally occurring salinities (i.e., freshwater to at least 37.8 ppt).
- 17. Document Analysis a. Descriptors Estuaries Fishes Growth Feeding
- b. Identifiers/Open.Ended Terms Atlantic silverside Life history Menidia menidia Spawning Salinity requirements Temperature requirements
- c. COSATI Field/Group
- 18. Availability Statement 19. Security Class (This Report) 21. No. of Pages Unclassified 15 Unl imited 20. Security Class (This Page) 22.
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REGION I REGION 2 REGION 3 Regional Director Regional Director Regional Director U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service Lloyd Five Hundred Building, Suite 1692 P.O. Box 1306 Federal Building, Fort Snelling 500 N.E. Multnomah Street Albuquerque, New Mexico 87103 Twin Cities, Minnesota 55111 Portland, Oregon 97232 REGION 4 REGION 5 REGION 6 Regional Director Regional Director Regional Director U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service Richard B. Russell Building One Gateway Center P.O. Box 25486 75 Spring Street, S.W. Newton Corner, Massachusetts 02158 Denver Federal Center Atlanta, Georgia 30303 Denver, Colorado 80225 REGION 7 Regional Director U.S. Fish and Wildlife Service 1011 E. Tudor Road Anchorage, Alaska 99503
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