Species Profiles: Life Histories andEnvironmental Requirements of Coastal Fishesand Invertebrates (Mid-Atlantic)

AMERICAN SHAD

QL155.S63no. 8211.37

L LFish and Wildlife ServiceU.S. Department of the Interior U.S. Army Corps of Engineers

Coastal Ecology GroupWaterways Experiment Station

Biological Report 82(11~7)April 1985

LibraryNational Wetlands Reetaflh Center11 c Ftsh and Wdllfe Sefllce700 cajundome EWJ~Lafayette, La. 70506

TR EL-824

This is one of the first reports to be published in the new "BiologicalReport" series. This technical report series, published by the Researchand Development branch of the U.S. Fish and Wildlife Service, replacesthe "FWS/OBS" series'published from 1976 to September 1984. The Biolog-ical Report series is designed for the rapid publication of reports withan application orientation, and it continues the focus of the FWS/OBSseries on resource management issues and fish and wildlife needs.

Biological Report 82(11.37)TR EL-82-4April 1985

Species Profiles: Life Histories and Environmental Requirementsof Coastal Fishes and Invertebrates (Mid-Atlantic)

AMERICAN SHAD

Chet MacKenzieLori S. Weiss-Glanz

andJohn R. Moring

Maine Cooperative Fishery Research Unit313 Murray Hall

University of MaineOrono, ME 04469

Project OfficerJohn Parsons

National Coastal Ecosystems TeamU.S. Fish and Wildlife Service

1010 Gause BoulevardSlidell, LA 70458

Performed forCoastal Ecology Group

Waterways Experiment StationU.S. Army Corps of Engineers

Vicksburg, MS 39180

and

National Coastal Ecosystems TeamDivision of Biological Services

Research and DevelopmentFish and Wildlife Service

U.S. Department of the InteriorWashington, DC 20240

This series should be referenced as follows:

U.S. Fish and Wildlife Service. 1983-19 . Species profiles: life historiesand environmental requirements of coasts fishes and invertebrates. U.S. FishWildl. Serv. Biol. Rep. 82(H). U.S. Army Corps of Engineers TR EL-82-4.

This profile should be cited as follows:

MacKenzie, C., L.S. Weiss-Glanz, and J.R. Moring. 1985. Species profiles: lifehistories and environmental requirements of coastal fishes and invertebrates(mid-Atlantic)--American shad. U.S. Fish Wildl. Serv. Biol. Rep. 82(11.37).U.S. Army Corps of Engineers TR EL-82-4. 18 PP-

PREFACE

This species profile is one of a series on coastal aquatic organisms,principally fish, of sport, commercial, or ecological importance. The profilesare designed to provide coastal managers, engineers, and biologists with a briefcomprehensive sketch of the biological characteristics and environmental require-ments of the species and to describe how populations of the species may beexpected to react to environmental changes caused by coastal development. Eachprofile has sections on taxonomy, life history, ecological role, environmentalrequirements, and economic importance, if applicable. A three-ring binder isused for this series so that new profiles can be added as they are prepared. Thisproject is jointly planned and financed by the U.S. Army Corps of Engineers andthe U.S. Fish and Wildlife Service.

Suggestions or questions regarding this report should be directed to oneof the following addresses.

Information Transfer SpecialistNational Coastal Ecosystems TeamU.S. Fish and Wildlife ServiceNASA-Slide11 Computer Complex1010 Gause BoulevardSlidell, LA 70458

or

U.S. Army Engineer Waterways Experiment StationAttention: WESER-CPost Office Box 631Vicksburg, MS 39180

iii

Multiply BY To Obtain

millimeters (mn) 0.03937 inchescentimeters (cm) 0.3937 inchesmeters (m) 3.281 feetkilometers (km) 0.6214 miles

square meters (m2) _square kilometers (km‘)hectares (ha)

10.76 square feet0.3861 square miles2.471 acres

liters (1) 0.2642cubic meters (m3)

gallons35.31 cubic feet

cubic meters 0.0008110 acre-feet

milligrams (mg) 0.00003527 ouncesgrams (9) 0.03527 ounceskilograms (kg) 2.205 poundsmetric tons (t) 2205.0 poundsmetric tons 1.102 short tonskilocalories (kcal) 3.968 British thermal units

Celsius degrees 1.8("C) + 32 Fahrenheit degrees

inches 25.40 millimetersinches 2.54 centimetersfeet (ft) 0.3048 metersfathoms 1.829 metersmiles (mi) 1.609 kilometersnautical miles (mii) 1.852 kilometers

square feet (ft')acressquare miles (mi2)

0.0929 square meters0.4047 hectares2.590 square kilometers

gallons (gal) 3.785 literscubic feet (ft3) 0.02831 cubic metersacre-feet 1233.0 cubic meters

ounces (oz)pounds (lb)short tons (ton) . .

CONVERSION TABLE

Metric to U.S. Customary

U.S. Customary to Metric

28.350.45360.9072

British thermal units (Btu) 0.2520

Fahrenheit degrees 0.5556("F

iv

32) Celsius degrees

gramskilogramsmetric tonskilocalories

CONTENTS

PREFACE . . . . . . . . . . . . . . . . . . . . . . . .CONVERSION TABLE . . . . . . . . . . . . . . . . . . .ACKNOWLEDGMENTS. . . . . . . . . . . . . . . . . . . .

NOMENCLATURE/TAXONOMY/RANGE. . . . . . . . . . . . . .MORPHOLOGY/IDENTIFICATON AIDS. . . . . . . . . . . . .REASON FOR INCLUSION IN SERIES . . . . . . . . . . . .LIFE HISTORY . . . . . . . . . . . . . . . . . . . . .

Spawning. ....................Fecundity and Eggs. ...............Larvae to Adults. ................Ocean Migratiorl .................

GROWTH CHARACTERISTICS ................THE FISHERY. .....................

History .....................Current Statistics. ...............Population Dynamics ...............

ECOLOGICAL ROLE. ...................Foods . . . . . . . . . . . . . . . . . . . . . .Predators ....................Diseases. ....................

ENVIRONMENTAL REQUIREMENT5 ..............Salinity. ....................Temperature ...................Oxygen . . . . . . . . . . . . . . . . . . . . . .Turbidity ....................Substrate ....................Depttt . . . . . . . . . . . . . . . . . . . . . .Water Movement. .................

LITERATURE CITED ...................

V

Page

iiiivvi

113334566777

10111112121212121313131313

15

ACKNOWLEDGMENTS

The authors thank Christine M. Moffitt, Idaho Cooperative Fishery ResearchUnit, University of Idaho; Richard J. Neves, Virginia Cooperative FisheryResearch Unit, Virginia Polytechnic Institute and State University; and Roy W.Miller, Division of Fish and Wildlife, Dover, Delaware, for reviewing portions ofthe manuscript.

vi

Figure 1. The American shad.

AMERICAN SHAD

NOMENCLATURE/TAXONOMY/RANGE

Scientific name . . Alosa sapidissima(Wilson)

Preferred common name . . . Americanshad (Figure 1).

Other common names . . shad, alose,common shad, Atlantic shad, NorthRiver shad, Potomac shad, Connecti-cut River shad, Delaware shad, Sus-quehanna shad, white shad, buck shad(males only), poplarback shad (Scottand Crossman 1973).

Class . . . . . . . . . OsteichthyesOrder . . . . . . . . . ClupeiformesFamily. . . . . . . . . . . Clupeidae

Geographic range: American shad areanadromous. They are distributedalong the Atlantic coast from New-foundland to Florida, and are mostabundant from Connecticut to NorthCarolina. In the mid-Atlanticregion the American shad ascendessentially all major rivers, butabundance in some rivers is limitedby pollution or restricted by dams(Figure 2).

On the Pacific coast, theAmerican shad was introduced intothe Sacramento and Columbia Riversin 1871, and the species is nowestablished from southern Californianorthward to Cook Inlet, Alaska, andthe Kamchatka Peninsula in Asia.

MORPHOLOGY/IDENTIFICATION AIDS

Body elongate, strongly com-pressed laterally, and rather deep,its depth 17%-19% of total length (TL)(Leim 1924; Bigelow and Schroeder1953; Scott and Crossman 1973). Headbroadly triangular, 22%-24% of TL.Gill membranes free from isthmus. Eyemoderate, adipose e.yelid well devel-oped, diameter of eye 27%-32% of headlength (HL); snout moderate, length27%-32% HL; interorbital width 19%-22%of HL. The anterior end of the lowerjaw not especially thick or heavy andsomewhat pointed, and fitting easilyinto a deep notch in upper jaw so thatthe jaws are about equal when themouth is closed. The upper outline ofthe lower jaw slightly concave. Maxil-lary extending to posterior margin ofeye. Teeth small, weak, and few in

1

NEW YORK

PHILADELPHIA

ATLANTIC OCEAN

3

eN

I

M I L E S

OV

K I L O M E T E R S

NORTH CAROLINACAPE HATTERAS

Figure 2. American shad are distributed along the coast of the Mid-AtlanticRegion from Massachusetts to North Carolina, but are most abundant in thisregion along the coast from Connecticut to North Carolina. They ascendessentially all major rivers but may be limited in some rivers by pollutionor restricted by dams.

2

number on premaxillary and mandible(lost completely in the adult) and ab-sent on the roof of the mouth. Gillrakers on lower limb 59-73; branchio-stegal rays 7,7 (rarely 7,6). Finssoft rayed: dorsal-l, height moderate,base short, ll%-13% of TL, rays 15-19,usual1.y 17-15; caudal,forked; anal-l,

distinctly

than dorsalbase length greater

base, 13%-14% of TL,height shorter than dorsalrays 18-24,

height,usually 20-22; pelvics,

abdominal, small,rays 9;

length 9%-10% of TL,pectorals, low on sides,

length 14%-15% of TL, rays 14-18,Iusually 16. Scales, large, crenulateon posterior margin, deciduous.Lateral line poorly developed withabout 50-55 scales. Ventral scuteswell developed forming a sharp saw-belly, prepelvic scutes 19-23, usually20-22, postpelvic scutes 12-19, usual-ly 15-17.55-58.

Vertebrae 53-59, usuallyPeritoneal lining pale; pylor-

ic caeca numerous and usually c,luster-ed on right side. Usually 4 to 6black spots in horizontal row behindoperculum. Size: average total length380 mm; males up to 2.7 kg; females upto 3.6 kg, rarely to 5.4 kg.

REASON FOR INCLUSION IN THE SERIES

Historically, commercial fishingfor American shad on the Atlanticcoast has been intensive and wide-spread. Now the fishery has virtuallycollapsed and is important only in afew rivers (Connecticut R.,Connecticut; Hudson R., New York;Neuse R., North Carolina; York R.,Virginia) in the mid-Atlantic region.In the rivers that support strongruns, sport fishing for shad is moreimportant than commercial fishing.Federal and State agencies haveinitiated management programs aimed atrestoring American shad to theirformer range and abundance. TheAmerican shad is a natural resourcethat should be considered forprotection in coastal and riverinedevelopment projects.

LIFE HISTORY

Spawning

The American shad is an anadro-mous fish that lives several years inthe ocean and then returns to itsriver of origin to spawn. At onetime, the species probably spawned invirtually every accessible river andtributary along the Atlantic coast ofNorth America.

The freshwater spawning migrationin winter, spring, or summer is timedto correspond to favorable river watertemperatures. Shad usually migratefar enough upstream so that the eggsdrift downstream and hatch beforereaching saltwater. In one study inthe Connecticut River, low rivertemperatures may have delayed thematuration of gonads causing the shadto migrate farther upstream to spawn(Marcy 1976). Glebe and Leggett(1981) reported that the gonads ofAmerican shad mature prior to enteringthe Connecticut River.

American shad spawn as early asmid-November in Florida and as late asJuly in some Canadian rivers. Malesarrive at the spawning grounds beforefemales (Chittenden 1975). Watertemperature is the primary factor thattriggers spawning, but photoperiod,flow velocity, and water turbidityalso exert some influence (Leggett andWhitney 1972).

Although shad eggs in Virginiastreams become abundant after thewater temperature reach 12°C (Massman1952), most spawning is from 13" to20°C (Walburg and Nichols 1967). InNorth Carolina, peak spawning is atwater temperatures near 20°C (Sholar1976).

The diameter and abundance ofshad eggs collected in plankton netsin the Pamunkey River, Virginia,indicate that spawning takes place atall hours of the night and day but is

3

more intense from noon to midnight(Massman 1952). According to Milleret al. (1971, 1975), spawning beginsin the evening between 1900 h and2000 h and peaks between 2100 h and2300 h in the Delaware River. After0100 n, most of the spawning subsides.On overcast days, spawning beginsearlier than on clear days, whichsupports the hypothesis that the dailyonset of spawning is regulated bylight intensity (Miller et al. 1982).

Group spawning involving severalmales and a female has been observed(Marcy 1972). The spawning fish swimvigorously at the surface, forming aclosely packed circle. Eggs arereleased into the water and thenfertilized by the males (Marcy 1972;Scott and Crossman 1973).

Shad spawn in main streams ofNorth Carolina rivers over sand shoalswhere there is sufficient current tokeep the eggs suspended in the watercolumn (Sholar 1976). Shad spawn oversand, silt, muck, gravel, and bouldersubstrates (Mansueti and Kolh 1953;Walh?rrg 1960; Leggett 1976). Theyspawn in water depths about 1 to 10 m(3 to 30 ft) but most often less than3 m (10 ft) (Walburg and Nichols1967). The current in spawning areasranges from about 0.5 to 3 ft/s(Walburg and ,Nichols 1967; Marcy1972).

The percentage of shad that spawnmore than once increases from south tonorth (Table 1). For example, shad inrivers south of Cape Fear, NorthCarolina, die after spawning, but inmore northerly rivers some shadsurvive spawning to spawn again. Shadmay return to spawn for up to 6years (Table 2). The percentage ofrepeat spawners ranges from 0% for theSt. Johns River, Florida, south ofCape Fear, North Carolina, to 73% inthe St. John River, New Brunswick(Carscadden and Leggett 1975a, 1975b).The Delaware River, unlike other mid-Atlantic coast shad rivers, has fewrepeat spawners (1.5% to 6.5%)

Table 1. The percent of repeatspawners in American shad spawningruns in 4tlantic coast rivers (Leggettand Carscadden 1978).

- - -River and Latitude Repeatlocation of river ("N) spawners(%)

Miramichi (NB) 49 64St. John (NB) 45 73Connecticut (CT) 41 63Hudson (NY) 41 57Delawarea (DL) 40 6Susquehanna (VA) 40 37Potomac (VA) 38 20York (VA) 37 24James (V4) 37 27Neuse (NC) 35 3Edisto (SC) 33 0Ogeechee (GA) 32 0St. Johns (FL) 30 0- -___~

a Chittenden (1975).

according to Chittenden (1975). Hesuggests that the probable causes forthe scarcity of repeat spawners thereare pollution and overfishing.

Fecundity and Ew

The American shad has a rela-tively high fecundity (116,000 to659,000 eggs per female; Table 2).Many eggs fail to fertilize and only asmall percentage of the fertilizedeggs hatch. High egg mortality hasbeen attributed to failure to fer-tilize, suffocation, fungus infection,and predation (Leach 1925; Mansuetiand Kolb 1953).

The fecundity of spawners de-creases from south to north (Table 3).These trends in fecundity are in-dependent of age and size.

Unfertilized eggs are irregularlyround in form and are about 1.8 mm indiameter; fertilized, waterhardenedeggs are 2.5 to 3.5 mm in diameter and

4

Table 2. Lengths, weights, ages, and range of the number of eggs of Ameri-can shad in the spawning populations of seven Atlantic coast rivers of theUnited States, 1951-1959 (Walburg and Nichols 1967).

-~ -Range of

Fork Body Age number of eggsRiver length (mm) weight (kg) (years) per female

(x 1,000)__--__

Hudson (NY) 355-556 0.8-3.0 3-9 116-468Potomac (VA) 460-505 1.4-2.4 5-6 267-525York (VA) 399-470 1.1-2.1 4-6 169-436Neuse (NC) 447-498 1.8-2.7 4-6 423-547Edisto (SC) 465-498 1.6-2.2 4-5 360-480Ogeechee (GA) 457-475 1.7-2.2 4-6 359-501St. Johns (FL)_ 368-460 0.6-1.8 4-6 277-659- _ ____-_-____

Table 3. Mean virgin (first timespawners) and lifetime fecunditiesof American shad populations fromfive Atlantic coast rivers, 1958-1973 (Leggett and Carscadden 1978).

- -Virgin Lifetime

River fecundity fecundity- -

St. Johns (FL) 406,000 406,000York (VA) 259,000 327,000Connecticut (CT) 256,000 384,000St. John (NB) 135,000 273,000Miramichi (NB) 129,000 258,000

are transparent, pale pink, or amber(Marcy 1976; Miller et al. 1982).Fertilized eggs are slightly heavierthan water and are nonadhesive. Therate of development of shad eggs islinearly related to temperature(Mansueti and Kolb 1953). Eggs hatchin 8 to 12 days at 11" to 15°C: 6 to 8days at 17°C; and 3 days at 24°C(Bigelow and Schroeder 1953; Scott andCrossman 1973). No viable eggsdevelop at water temperatures above29°C (Bradford et al. 1966).

Larvae to Adults

American shad yolk-sac larvae areabout 6 to 10 mm long (TL) at hatchingand 9-12 mm TL when the egg yolk is

absorbed (Marcy 1976). Initially thelarvae 9-27 mm TL are planktonic(Mansueti and Hardy 1967; Jones et al.1978). They reach the juvenile stagewhen about 25 to 28 mm long and about4 weeks old (Jones et al. 1978).Juveniles spend the first summer inthe river feeding on crustaceans and -aquatic insects at the surface or inthe water column (Leim 1924: Walburg1957; Levesque and Reed 1572).

In the fall, juveniles (75 to 125mm long) migrate down the rivers tobrackish water and then to the sea. Adecrease in river water temperatureseems to trigger the migration(Chittenden 1972). Juvenile shadmigrate seaward first in northernriverssouthern

a n d progres;~v;~ttlaterrivers

Juvenile shad leave the St.1977;:Johns

River, Florida, as the water cools to15.5OC (Walhurg 1960). In theDelaware River, shad begin movingdownstream when the water temperaturedrops to about 20°C; the movementpeaks at 15°C (Sykes and Lehman 1957).In the Connecticut River, downstreammigration peaks late in September andOctober. Peaks for the Upper DelawareRiver and the Chesapeake Bay arc? lateOctober and late November, respect-ively. Once in the ocean, the shadremain there until they mature.

5

Males become sexually mature whenthey are 3 to 5 years old and thefemales mature at 4 to 6 years old(Leim 1924). Most of the malefirst-time (virgin) spawners in theNeuse (North Carolina) and Susquehanna(Maryland) Rivers are 4 years old(LaPointe 1958). The majority offemale virgin spawners are 4 to 5years old. Shad are known to completetheir entire life cycle in only onefreshwater system: Millerton Lake, areservoir on the San Joaquin River,California (Lambert et al. 1980).

Morphological characteristics fordistinguishing shad larvae from otherlarvae of similar species aredescribed by Jones et al, (1978).

Ocean Migration-

The American shad in the mid-Atlantic region form large schools andundertake extensive ocean migration(Leggett and Whitney 1972). Shad fromall Atlantic coast rivers spend thesummer and fall in the Gulf of Maine(Talbot and Sykes 1358). Thiscongregation includes immature shadand spawned-out adults from riversnorth of Chesapeake Bay. Shad areapparently scattered along themid-Atlantic coast during the winter(Talbot and Sykes 1958; Walburg andNichols 1967). Migrating Americanshad seek bottom water temperaturesbetween 3" and 15°C but probablyprefer temperatures between 7" and13°C (Neves and Depres 1979).

In early spring, the schooyho;zshad migrate toward the coast.returning to rivers south of CapeHatteras follow the Gulf Stream toremain within the 3" to 15'C bottomisotherm. Those migrating to riversnorth of Cape Hatteras later in thespring follow a route farther seawardinto the Middle Atlantic Bight wherewater temperatures have risensufficiently. Tag returns indicatethat some schools migrate north alongthe coast (Neves and Depres 1979).

American shad migrate as much as21 km/day in Chesapeake Bay andsot:;Bay of Fundy (Leggett 1977).migrate iup to 3,000 km during thespring or fall migration.

A large majority of American shadreturn to their natal river to spawn.Homing behavior involves both olfac-tion and rheotaxis (Dodson and Leggett1974). The homing mechanism issufficiently robust to perpetuatemigrations even after major changes inwater flow, such as below ahydroelectric dam.

GROWTH CHARACTERISTICS

American shad live to be 5 to 7years old and most weigh between 1 to3 kg. The oldest shad reported forthe United States was 11 years of ageand 584 mm long (Scott and Crossman1973). Factors that affect growthsometimes can be identified byexamining fish scales. Slow growth inthe winter causes growth rings onscales to be close together; thesewinter marks (annuli) can be used toage fish. Judy (1961) verified thescale method for aging American shad.He also noted a mark on the scalesthat formed when the juveniles leftfresh water, and described marks thatformed at spawning. Shad grow about100 mmlyr until sexually mature; aftermaturity, growth slows (Table 4).

Table 4. The average total lengths ofshad and annual growth increments (mm)for ages I to VII in the Bay of Fundy(Leim 1924).

GrowingSeason _ Age Length Increment- -1st I 1202nd II 240 1203rd III 320 804th IV 400 805th V 470 706th VI 520 507th VII 570 50

6

THE FISHERY

History-

In the 19th century, extensivefisheries for shad developed along theentire Atlantic coast from the St.Johns River, Florida, to the St.Lawrence River, Canada. Major typesof gear were drift and staked gillnets, pound nets, haul seines, weirs,fyke nets, bow nets, and dip nets.The estimated U.S. Atlantic coastcatch in 1896 was 22,680 metric tons(50 million lb). Between 1930 and1960, the average annual catch wasabout 4,530 metric tons or 10 millionlb (Figure 3). In 1983, landings wereabout 1,585 metric tons (3.5 millionlb).

Commercial shad landings inChesapeake Bay were traditionally thelargest along the Atlantic coast(Table 5), but because of the closureof Maryland's shad fishery in 1980,the mid-Atlantic and South Atlanticcatches have been greater. Dams,pollution, and overfishing havecontributed to the decline of shadstocks.

Current Statistics

Rhode Island. American shad arean incidental part of the commercialcatch in Rhode Island. Approximately77,000 lb were landed in 1982 (Table6). The Runnings and Warren Riverssupport a small sport fishery. Shad

AMERICAN SHAD - U.S. ATLANTIC COAST25000 -

Figure 3. Landings of American shad, U.S. Atlantic coast, 1880-1976 (Walburgoermission from Public Serviceand Nichols 1967;- updated and reproduced with

Electric and Gas Company, 80 Park Plaza, Newark, New Jersey 07101).

7

Table 5. The landings of American shad (x 1,000 lb) for different regionsalong the U.S. coast, 1960-83. Code: NE=New England, MA=Mid-Atlantic, CB=Chesapeake Bay, SA=South Atlantic, PC=Pacific Coast (1960-77, National MarineFisheries Service, Statistical Digest; 1978-83, National Marine FisheriesService, unpublished data).

-___ -

Year NE

Coastal regions -

MA CB SA PC

1960 432 1,237 2,682 1,614 4561961 547 1,026 3,144 1,612 9271962 470 841 3,795 2,167 1,5861963 325 744 3,139 1,734 1,5031964 320 721 3,541 1,687 8181965 380 635 4,298 2,379 8701966 279 379 3,564 1,736 1,3471967 754 387 3,005 1,562 1,3331968 218 379 3,508 2,052 8621969 201 342 3,540 1,904 6101970 186 314 5,151 1,851 7241971 283 222 2,473 1,452 4991972 264 375 3,014 1,091 7091973 261 308 3,033 685 4831974 257 294 1,789 655 5111975 208 337 1,321 518 5221976 412 322 1,006 320 4811977 418 394 1,547 418 5601978 361 245 1,322 976 5451979 330 216 1,041 363 7971980 253 406 998 839 2771981 66 510 500 1,235 1201982 403 757 590 1,033 4291983 504 365 242 1,974 413

have been reintroduced unsuccessfullyin the Pawcatuck River, in an attemptto restore a spawning populationthere; the river is currently closedto shad fishing.

Connecticut. The ConnecticutRiver supports a modest commercialshad fishery. Most fishing is withdrift gill nets below Hartford atnight. Some fishing is done duringthe day when the water is turbid.Fyke, trap, and pound nets are notallowed in the river during the shadrun. The primary market is for roe(eggs); males (buck shad) have littleor no value. The State of Connecticut

carefully regulates commercial fishingfor shad on the Connecticut River.The season is open to commercialfishing from April 1 to June 15.During the season, fishing isprohibited from Friday sunset toSunday sunset. Monofilament gill netsare prohibited and the gill nets usedmust have a minimum stretch Imeasure of5 inches. There are no size or sexrestrictions. License holders mustreport their catch at the end of eachfishing season.

Sportfishing for shad in Con-necticut is permitted from April 1 toa closing date determined each year.

Table 6. Annual (1960-83) commercial landings (x 1,000 lb) of American shadfrom Rhode Island, Connecticut, New York, New Jersey, Maryland, and NorthCarolina (1960-77, National Marine Fisheries Service, Statistical Digest;1978-83, National Marine Fisheries Service, unpublished preliminary data).

Year196019611962196319641965196619671968196919701971197219731974197519761977197819791980198119821983

RhodeIsland

347234

23526

124214

276311121

7723

Connecticut421463456301278352242240212190173241249258247165392392332306207325283424

New NewYork Jersey472 694303 633243 480202 442141 430133 392ai 242

113 248126 241136 188106 195

73 141103 263157 143164 122196 122186 100

1 1942 160a 148

114 29258 25973 33433 112

Mary1 and1,3361,8151,575

a27890

1,3431,133

867958

1,2921,039

953957597220184110

77a74724

19

27

NorthCarol ina

702673765693640

1,069701777a42719953680468321369241167120402278199352412380

Angling and scoop nets are permittedin streams. The daily bag limit issix fish.

New York. The Hudson River hasthe only commercial American shadfishery of note in New York. Gillnets are the principal type ofcommercial gear used. Staked gillnets contribute about 70% of the gillnet catch and drift gill nets contri-bute 30%.

New Jersey. Most commercialfishing (almost entirely with gillnets) in New Jersey is concentrated inDelaware Bay; there is no sportfishery in the bay. The only sportfishery begins about 90 mi up theDelaware River near Trenton, NewJersey. Shad from the Delaware Riverhave been stocked into the Raritan

9

River basin in an attempt to restorethe once abundant runs there:, however,all attempts of restoration havefailed (Didun 1983).

Pennsylvania. There is no com-mercial fishery for American shad inPennsylvania, but major restorationattempts are underway on theSusquehanna and Schuylkill Riverswhere sport fishing for shad iscurrently banned. The estimatedannual value of the sport fishery onthe Schuylkill River fishery will be$1,200,000 if the goal of restorationis achieved (Mulfinger and Kaufmann1980). Estimates of the annual valueof the current sport fishery on theupper Delaware River range from$828,000 to $3,000,000 (Miller et al.1982).

Delaware. The legal commercialgear in Delaware is 5- to 6-inch(stretch measure) gill nets. Fishingis allowed from March until early May.In the past 30 years, the fishery hasshifted from the lower Delaware River,where drift gill nets were used, toDelaware Ray, where anchored gill netspredominate (Miller 1982). Theincrease in the commercial catch ofAmerican shad in the Delaware Estuaryin recent years gives some evidencethat the species is becoming moreabundant (Table 7). The increase isattributed partly to recentlycompleted pollution abatement projectsin the lower Delaware River (Miller1982). There is no sport fisheryexcept for Nanticoke River and BroadCreek, tributaries to Chesapeake Bay.The fishing season for the Delawarewaters of the Delaware Estuary is fromJune 10 to February 1.

Maryland. A sharp decline in thecommercial catch of American shad inMaryland began in 1973 (Table 6).This led to the closing of all watersin varyland to shad fishing with theexception of the Potomac River (whichis regulated by the Potomac RiverFisheries Commission) and coastalwaters (Carter and 'rleinrich 1982).

Table 7. American shad catch (x 1,000lb) and value (x 1,000 dollars) forDelaware and Virginia (Miller 1982;Jack Travelstead, Virginia MarineResources Commission; pers. comm.).

Date Delaware VirginiaCatch Value Catch Value- -

1960 38 6 1.349 2341965 110 16 21955 3071970 13 1 4,112 3151975 19 4 1,137 3091976 36 8 896 284I977 75 15 1,469 4981978 70 20 1,235 2121979 95 15 994 2351980

1;;31 974 353

1981 87 499 1411982 333 585 180

Virginia. The biggest Americanshad fishery is along the Atlanticcoast of Virginia. In 1982, 585,000pounds were landed with a value of$180,028 (Table 7). Gill nets are theprimary gear used.

North Carolina. In NorthCarolina, shad are caught by commer-cial and sport fishermen from lateJanuary to the end of March. Thecommercial fishery employs drift andstaked gill nets, pound nets, andseines. The primary types of gearused on the Neuse River, which hasthe largest commercial catch, arestaked and drift gill nets (Hawkins1980).

Population Dynamics_~

Recruitment into the shad fisheryis largely dependent on the size ofthe spawning stock and environmentalfactors that govern spawning successand survival. About 85% of thevariation in the numbers of Americanshad that spawn in the Hudson River inany one year is largely dependent onthe number of spawners 5, 4, and 1year earlier (Talbot 1954). About 64%of the annual variation in the abun-dance of juvenile shad in theConnecticut River from 1966 to 1973was directly related to the number ofspawners; 22% was attributed toenvironmental factors, principallywater temperature and river flowduring the run (Marcy 1976).

The rate of exploitation is amajor factor influencing changes inthe abundance of shad in theConnecticut River (Leggett 1976).Because of the high value of shad eggs(roe), females in the spawning run arethe main targets of the fishery.

The number of adults that survivethe fishery in any one year isdirectly correlated with the numbersof fish produced in the nextgeneration. This relationship isdescribed by a stock-recruitmentequation:

10

q = N 0.7 (I - N/87)e

where R is recruitment and N is theparent stock in terms of egg numbers(Leggett 1976). Average annualmortality rates, calculated fromtag-recaptures data, were about 70%for males and 71% for females from1965 to 1973 in the Connecticut River(Leggett 1976).

The age structure of Americanshad returning to spawn in Delawareand North Carolina consists primarilyof 4- and 5-year-old males and 5- and6-year-old females (Table 8).

ECOLOGICAL ROLE

Foods

Apparently, young American shadin rivers feed mostly in the water

bcolumn (Levesque and Reed 1972;Domermuth and Reed 1980). Early shadlarvae feed mostly on cyclopoidcopepods and tendipedids (Levesque andReed 1972). The stomach contents of

Table 8. Age composition (%) of thespawning population of American shad

Delaware;Fhitttheenden

River, Delaware1975), and the Neuse

River, North Carolina (Hawkins 1980).

Delaware North CarolinaAge Number % Age Number %

III I IIVVVI

IVVVIVII

Males

: 00 2'6236 76:l62 20.03 0.0

Females225: 61.6 13.7

88 24.12 0.0

MalesI I I 16IV 126 3;V 151 46VI 310 9VII 3 1

FemalesIVV 444: 5:VII 10 1VIII 1 0

juvenile (35-85 mm FL x = 55 mm) shadsix Atlantic coast rivers (St.

A!hns, Florida; Ogechee, Georgia;Neuse, North Carolina; Pamunkey,Virginia; Hudson, New York;Connecticut, Connecticut) suggestedthat shad ate suitable organisms thatwere most available (Walburg 1957).In contrast, a study performed on theConnecticut River, Connecticut, byDomermuth and Reed (1980)demonstrated that juvenile shad (Tl =28 to 132 mm x = 63.3 mm) wereselective; i.e., most selected daphnia(51%) and bosmids (20%), whereasdespite high abundance, copepods (8%)and benthos (0.1%) were consumed insmall quantities.

After going to sea, juveniles andadults feed on a variety of smallcrustaceans, many of which are benthicorganisms. Copepods and mysidsconstituted 90% of the diet of adultshad in the Bay of Fundy (Leim 1924).Adults also feed on small fishes,euphausids, fish eggs, and amphipods(Bigelow and Schroeder 1953; Scott andCrossman 1973). Most shad have a die1vertical migration that follows thedie1 migration of their principalfood, zooplankton (Neves and Depres1979). In a study off the coast ofNorth Carolina, 'anchovies (Anchoahepsetus) were in 12 of the 15juvenile shad examined (87-141 mm),and 39 of 41 adults (Holland andYelverton 1973). The stomachs alsocontained zooplankton under 5 mm(Holland and Yelverton 1973). Thissize was reported by Atkinson (1951)as being too small for shad gillrakers to retain.

Food was scarce in the stomachsof shad migrating upstream to spawn(Leim 1924). But in one experiment,migrating prespawning shad placed in afreshwater pond fed on artificial feed(Atkinson 1951).

Adult shad fed on mayflies infreshwater and their stomachscontained the remains of small fish(Chittenden 1976). Shad strike;

11

artificial lures when in freshwater, abehavior unexplained.

Predators

Juvenile shad may be preyed uponby a variety of predators in fresh-waters (Scott and Crossman 1973), butLeim (1924) was unable to demonstratepredation by either American eels(Anguilla rostrata) or striped bass(Morone sax-in the ShubenacadieRiver, Nova Scotia. Seals prey onAmerican shad, but adults probablyhave few enemies, except for humans(Scott and Crossman 1973).

Diseases

The American shad has the usualcomplement of parasites and diseases.Acanthocephala, parasitic copepods,distomes, nematodes, and trematodeshave all been reported in or on shad(Scott and Crossman 1973). In theConnecticut River, the sea lamprey(Petromyzon marinus) and freshwaterlampreys (Ichthyomyzon spp.) sometimesattach to adult shad (Walburg andNichols 1967).

ENVIRONMENTAL REQUIREMENTS

Salinity

The American shad adapts readilyto either freshwater or seawaterduring its anadromous migrations. Theadults may spend two to three days inthe estuary before entering the river(Leggett 1976). One test was made inthis connection. Transfer of adultshad from seawater to freshwater overa 2.5 hour period caused physiologicstress and a mortality of 54% (Leggettand O'Boyle 1976).

Eggs are always deposited infreshwater and are believed to beintolerant of full-strength seawater.Leim (1924) suggests that shad eggsand larvae tolerate brackish waterwith a salinity as high as 15 ppt.

Temperature

Spawning runs into rivers(Columbia River, Washington;Connecticut River, Connect.icut-Massachusetts; St. Johns River,Florida) at various latitudes on thePacific and Atlantic coasts of NorthAmerica peak at water temperatures of15.5' to 2O.O"C (Leggett and Whitney1972).

The rate of development of shadlinearly related

~~$erat~~e (Mansueti and Kolh ,953;:Eggs hatch in 8 to 12 days at 11' to15°C; 6 to 8 days at 17“C and 3 daysat 24°C. (Leim 1924; Bigelow andSchroeder 1953; Scott and Crossman1973). E!w stop developing whenwater temperatures drop to 7°C (Leim1924). Abnormalities develop when thetemperature rises to 22OC (Leim 1924),and no viable larvae develop from eggsat water temperatures above 29°C(Bradford et al. 1966).

The American shad is intolerantof cold water temperatures. The lowerthermal tolerance limit is about 2°Cbut prolonged exposure to 4" to 6°Cmay cause high mortality or stress(Chittenden 1972). If young shad aregiven a choice, they generally avoidtemperatures below 8°C and stronglyavoid temperatures below 5°C.Chittenden concluded that cold waterreleases below large impoundments maycurtail or destroy historical spawningand nursery areas there.

Juvenile American shad attempt toavoid excessively high or rapidincreases in water temperature. Testsin tanks show that shad avoidtemperature increases of about 4°Cabove the acclimation temperature(Moss 1970). They did not attempt toavoid changes of l"C, suggesting asensory threshold of between +l" and+4"C above ambient temperature.

Field observations bear out thelaboratory findings of Chittenden(1972) and Moss (1970). Migrations of

17

American shad in the ocean andfreshwater are closely tied to changesin vfater temperature. Shad are mostfrequently caught commercially inocean bottom temperatures of 7' to13°C (Neves and Depres 1979).

Oxygen

The American shad require well-oxygenated waters either in rivers orin the sea. Dissolved oxygen levelsmust be at least 4 to 5 mg/l inheadponds through which shad pass intheir migration (Jessop 1975). In thelaboratory, equilibrium is lost atdissolved oxygen levels below 3 mg/l;heavy mortality occurs at :evels below2 mg/l; and all fish die at concen-trations less than 0.6 mg/l(Chittenden 1969). Shad eggs wereabsent where the concentration ofdissolved oxygen was lower than 5 mg/l(Marcy 1976). The oxygen LCso forConnecticut River shad eggs is 2.0 to2.5 mg/l (Carlson 1968).

Turbidity

Extensive dredging of the HudsonRiver produced no measurable adverseeffects on shad abundance (Talbot1954). Adult shad readily enter theShuebenacadie River in Nova Scotia,where suspended sediment concentrationsometimes is 1 g/l (Leim 1924). In alaboratory study, mortality of eggsheld in concentrations of suspendedsediments up to 1 g/l from fertiliza-tion to hatching did not differsignificantly from control groups(Auld and Schubel 1978); however, thesurvival of shad larvae exposed toconcentrations greater than 0.1 g/lfor 96 hours was sharply reduced.Larvae apparently are much lesstolerant of suspended sediments thaneggs.

Substrate

Substrate type apparently isunimportant to shad. They spawn inthe water column and the eggs arecarried downstream. American shad

have been observed to spawn success-fully over silt, mud, sand, gravel,and boulders (Plansueti and Kolb 1953;Walburg 1960; Leggett 1976). Onlyunder the most adverse of conditions,in which mud covered and smothered theeggs, was substrate a problem.

Depth

American shad show little depthpreference in freshwater. Adults arecaught during spawning runs in allparts of the river channel. Spawninghas been observed in rivers at depthsranging from 0.45 to 7 m (Mansuetiand Kolb 1953; Walburg 1960; Kuzmeskus1977).

Juveniles were found at depths of0.9 to 4.9 m in the Connecticut River(Marcy 1976). Abundance was relatedto the distance upstream and not todepth. During the day, 87% of thejuvenile shad caught in a gill net:;req ;e",' the bottom at depths of 3.7

. . At night, all were caughtnear the surface. At sea, shad arenear the bottom during the day anddisperse in the water column at night(Neves and Depres 1979).

Water Hovement

Water velocity is critical toshad because shad must negotiate rivercurrents and occasional fishways whenmigrating upstream, and pass safelyover spillways while going downstream.Adult shad migrating upstream arereluctant to use traditional fishways,probably because entrance widths,depths, and flows are often unsuitable(Walburg and Nichols 1967). Pool-and-weir fishways, vertical-bafflefishways, and elevators are bettercarriers of American shad. For thepool-and-weir fishway, optimum differ-ence in pool elevations is 23 cm whenwater velocities are 61 to 91 cm/set.For any fish passage to work, propercurrent at the entrance is essential.

In the Connecticut River, thedaily movement upstream is about 5 km

.3

in brackish water, and 14 km in fresh-water (Leggett 1976). Adultdownstream migration depends on watercurrents and the pattern of currentsaround obstructions. In theFarmington River, a tributary of theConnecticut River, flow rate into thefishway accounts for 60% of thevariation in the number of downstreammigrants entering the fishway (Moffitt1979). No fish entered the tributarybecause of the lack of an adequateattractant flow. Fish that fail tofind the downstream passage must passover the spillway or throughhydroelectric turbines. Between 57%and 80% of juvenile shad that passthrough a 850 kw Ossberger turbine arekilled outright, and others may die

later of stress or are easy prey topredators (Gloss 1982). A fishway maycause mortality because of excessiveloss of scales and injury. At least25% of the shad die as a result of thefish-lift at Mactaquac, New Brunswick(Jessop 1975). Exposure to lethalnitrogen supersaturated waters belowthe dam sometimes causes stress ormortality (MacDonald and Hyatt 1973).

Spawning takes place in watervelocities ranging from 9.5 to 132cm/set based on hydrographic data atsites where Kuzmeskus (1977) foundfresh spawn. Spawning normally takesplace at velocities of 30 to 90 cm/set(Walburg 1960).

14

LITERATURE CITED

Atkinson, C.E. 1951. Feeding habitsof shad (Alosa sa idissima) infresh water.--4__TEcology 32 3):556-557.

Auld, A.H., and J.R. Schubel. 1978.Effects of suspended sediment onfish eggs and larvae, a labora-tory assessment. EstuarineCoastal Mar. Sci. 6(2):153-164.

Bigelow, H.B., and W.C. Schroeder.1953. Fishes of the Gulf ofMaine. U.S. Fish Wildl. Serv.Fish. Bull. 53. 577 pp.

b Bradford, A., J. Miller, and K. Buss.1966. Bio-assays on eggs andlarval stages of American shad(Alosa sapihissima). Pages 52-60in. Carlson.ae

Suitability ofSusquehanna River for

restoration of shad. U.S. Dep.Inter., Bur. of Sport Fish. andWildl. Washington, @.C.

Carlson, F.T. 1968. Suitability ofthe Susquehanna River for therestoration of shad. U. S. Dep.Inter., Bur. Sport Fish. andWildl. Washington, D.C. 60 pp.

Carscadden, J.E., and W.C. Leggett.1975a. Meristic differences inspawning populations of Americanshad, Alosa sapidissima: evidencefor homto tributaries in theSt. John River, New Brunswick. J.Fish. Res. Board Can. 32(5):653-660.

Carscadden, J.E., and W.C. Leggett.1975b. Life history variationsin populations of American shad,

Alosa sapidissima (Wilson),spawning in tributaries of theSt. John River, New Brunswick. J.Fish Biol. 7(50):595-609.

Carter, W.R., III, and D. Weinrich.1982. An overview of Maryland'sshad stocks. Tidal Fish. Div.,Md. Dep. Nat. Resour. 52 pp.

Chittenden, M.E., Jr. 1969. Life his-tory and ecology of the Americanshad, Alosa sa idissima% TihnesF?DelawareTRi;ver.

Rutgers University, New Bruns-wick, NJ. 458 pp.

Chittenden, Y.E., Jr. 1972. Responsesof young American shad, Alosasapidissz, to low temperatures.Trans. Am. Fish. Sot. lOl(4):680-685.

Chittenden. M.E.. Jr. 1975. Dvnamicsof American'shad, Alosa sapidis-sima. runs in the Delaware River.K'Natl. Mar. Fish. Serv. Fish.Bull. 73(3):487-494.

Chittenden, M.E., Jr. 1976. Weightloss, mortality, feeding and dur-ation of residence of adult Amer-ican shad, Alosa sapidissima, in.-fresh water. U.S. Natl. Mar.Fish. Serv. Fish. Bull.74(1):151-157.

Didun, A., Jr. 1983. The feasibilityof reestablishing American shad,(Alosa sap_idissima): RaritanBasinanadromous fish project.Fed. Aid in Fish Restor., Proj.AFS-6., New Jersey. Final Report.35 PP.

15

Dodson, J . J . , and W.C. Leggett. 1974.Role of olfaction and vision inthe behavior of American shad(Alosa sapidissima) homing to theConnecticut River from Long Is-land Sound. J. Fish. Res. BoardCan. 31(10):1607-1619.

Domermuth, R.B., and R.J. Reed. 1980.Food of juvenile 4merican shad,Alosa sapidissima, juvenile blue-back herring, Alosa aestivalis,and pumpkinseen>omis glbbo-*, in the Connecticut Riverbelow Holyoke Dam, Massachusetts.Estuaries 3(1):65-68.

Glebe, B.D., and W.C. Leggett. 1981.Temporal, intra-population dif-ferences in energy allocationand use by American shad (Alosasapidissima) during the spawningmigration. Can. J. Fish. Aquat.Sci. 38(7):795-805.

Gloss, S.P. 1982. Estimates of juve-nile American shad (Alosa s&-dissima) turbine moX%Xty atlow-head hydropower sites. Page22 in R.G. Howey, ed. Proceedingsof 1981 American shad workshop --culture, transportation andmarking. U.S. Fish Wildl. Serv.Lamar Infor. Leafl. 82-01.

Hawkins, J.H. 1980. Investigations ofanadromous fishes of the NeuseRiver, North Carolina. Spec.Sci. Rep. No. 34. N.C. Dept. ofNatur. Resour. Dev. 111 pp.

Holland, B.F. Jr., and G.F. Yelverton.1973. Distribution and biologicalstudies of anadromous fishesoffshore North Carolina. Spec.Sci. Rep. No. 24. N.C. Dep. Nat.Econ. Resour. 132 pp.

Jessop, B.M. 1975. A review of theAmerican shad (Alosa sapidissima)stocks of the St. John River, NewBrunswick, with particular refer-ences to the adverse effects ofhydroelectric developments. Can.

Fish. Mar. Serv. Resour., Dev.Branch Marit. Reg. Tech. Rep.Ser. Mar. T. 75-6:1-23.

Jones, P.W., F.D. Martin, and J .D.Hardy, Jr. 1978. Development offishes of the Mid-Atlantic Bight.Pages 98-104 in An atlas of egg,larval and juiile stages. Vol.I. U.S. Fish Wildl. Serv. Biol.Serv. Program. FWS/OBS-78/12.

Judy, M.H. 1961. Validity of agedeterminations from scales ofmarked American shad. U.S. FishWildl. Serv. Fish. Bull. 61:16I-170.

Kuzmeskus, D.M. 1977. Egg productionand spawning site distribution ofthe American shad, Alosa sapidis-*, in the Holyoke Pool, Con-necticut River, Massachusetts.M.S. Thesis. University of Massa-chusetts, Amherst. 134 pp.

Lambert, T.R., C.L. Toole, J.M. Hand-ley, M.A. Koeneke, D.F. Mitchell,and J.C.S. Wang. 1980. Environ-mental conditions associated withsoawnino of a landlocked Americanshad, Ajosa sa idissima, popula-tion. Am. -%X--20(4):813.(Abstr.)

La Pointe, D.F. 1958. Age and growthof the American shad, from threeAtlantic coast rivers, Trans. Am.Fish. Sot. 87:139-150.

Leach, G . C . 1925. Artificialpropagation of shad. Pages459-486 in U.S. Bur. Fish. DocketNumber 981, App. VIII, Rep. U.S.Comm. Fish., 1924.

Leggett, W.C. 1976. The Americanshad (Alosa sapidissima), withspecial reference to its migra-tion and population dynamics inthe Connecticut River. Am. Fish.Sot. Monogr. No. 1:169-225.

Leggett, W.C. 1977. Ocean migrationrates of American shad (Alosa

16

sa idissima). J. Fish. Res. BoardCi!hTpp422-1426.Leggett, W.C., and J.E. Carscadden.

1978. Latitudinal variation inreproductive characteristics ofAmerican shad (Alosa sa idis-sima): --+-evidence for popu ationsspecific life history strategiesin fish. J. Fish. Res. Board Can.35(11):1469-1478.

Leggett, W.C., and R.N. O'Boyle. 1976.Osmotic stress and mortality inadult American shad during trans-fer from saltwater to freshwater.J. Fish Biol. 8(6):459-469.

Leggett, W.C., and R.R. Whitney. 1972.Water temperature and the migra-tions of American shad. U.S.Natl. Mar. Fish. Serv. Fish.Bull. 70(3):659-670.

Leim, A.H. 1924. The life history ofthe shad (Alosa sapidissima(Wilson)) with special referenceto the factors limiting its abun-dance. Biol. Board Can., Contrib.Can. Biol. 2(11):163-284.

Levesque, R.C., and R.J. Reed. 1972.Food availability and consumptionbv vouna Connecticut River shadA-loss sapidissima. J. Fish. Res.Board Can. 29:1495-1499.

MacDonald, J.R. and R.A. Hyatt. 1973.Supersaturation of air in waterafter passage through hydro-electric turbines at MactaquacDam, Saint John River, NewBrunswick. J. Fish. Res. BoardCan. 30:1392-1394.

Mansueti, R.J., and J.D. Hardy, Jr.1967. Development of fishes ofthe Chesapeake Bay region. PartI. University of Maryland,College Park, MD, 202 pp.

Mansueti, R.J., and H. Kolb. 1953. Ahistorical review of the shadfisheries of North America. Ches-

apeake Biol. Lab. Publ. 97,Solomons, MD. 293 pp.

Marcy, B.C., Jr. 1972. Spawning ofthe American shad, Alosa sapidis,-sima, in the lower ConnecticutRiver. Chesapeake Sci. 13(2):116-119.

Marcy, B.C., Jr. 1976. Early lifehistory studies of American shadin the lower Connecticut Riverand the effects of theConnecticut Yankee Plant. Pages141-168 in Am. Fish. Sot. Monogr.No. 1. -

Massman, W.H. 1952. Characteristics ofspawning areas of shad, Alosasapidissima (Wilson), in someVirginia streams. Trans. Am.Fish. Sot. 81:78-93.

Miller, J.P., J.W. Friedersdorff, H.C.Mears, J.P. Hoffman, F.R.Griffiths, R.C. Reichard, andC.W. Billingsley. 1975. Annualprogress report Delaware RiverBasin Anadromous Fish Project,AFS-2-6. Jan., 1973-Jan., 1974.U.S. Fish Wildl. Serv. 223 pp.

Miller, J.P., F.R. Griffiths, and P.A.Thurston-Roqers. 1982. TheAmerican - shad (Alosa sapidis-sima) in the Delaware RiverBasin. 1982. Prepared for theDelaware Basin Fish and WildlifeManagement Cooperative, Rosemont,NJ. 132 pp.

Miller, J.P., W.M. Zarback, J.W.Friedersdorff, and R.W,Marshall. 1971. Annual progressreport Delaware River BasinAnadromous Fish Project, AFS-2-4.U.S. Fish Wildl. Serv. 66 pp.

Miller, R.W. 1982. An overview of thestatus of American shad (Alosasapidissima) in Delaware. Del.Div. Fish Wildl. 13 pp.

Moffitt, C.M. 1979. Recolonizationof American shad, Alosa sapidis-

17

sima (Wilson), above Rainbow Damfish-ladder, Farmington River,Connecticut. Ph.D. Thesis, Uni-versity of Massachusetts, Am-herst. 128 pp.

Moss, S.A. 1970. The responses ofyoung American shad to rapidtemperature changes. Trans. Am.Fish. Sot. 99(2):381-384.

Mu1 finger, R.M., and M.L. Kaufmann.1980. Fish passage at theFairmount fishway in 1979 and1980 with implications for theSchuylkill River fisheriesthrough fishway construction.Presented to The Academy o fNatural Sciences of Philadelphia,Schuylkill River Symposi urn.September 24 and 25, 1980.

National Marine Fisheries Service.1960-1977. Statistical Digest,Fishery Statistics of the UnitedStates. 1J.S. Dep. Commerce.Washington, DC.

Neves, R.J., and L. Depres. 1979. Theoceanic migration of Americanshad, Alosa sapidissima, alongthe At-i-%?% coast. U.S. Natl.Mar. Fish. Serv. Fish. Bull.77(1):199-212.

Scott, W.B., and E.J. Crossman. 1973.Freshwater fishes of Canada.Fish. Res. Board Can. Bull. 184.966 pp.

Sholar, T.M. 1976. Status of Americanshad in North Carolina. Pages17-31 in Proceedings of a work -shop on American shad, Dec.14-16, Amherst, MA. U.S. Fish

and Wildl. Serv. and Natl. Mar.Fish. Serv.

Stier, D.J. Habitat suitablity indexmodels: American shad. U.S. FishWildl. Serv. In press.

Sykes, J.E., and B.A. Lehman. 1957.Past and present Delaware Rivershad fishery and considerationsfor its future. U.S. Fish Wildl.Serv. Res. Rep. No. 46. 25 pp.

Talbot, G.B. 1954. Factors associatedwith fluctuations in abundance ofHudson River shad. U.S. FishWildl. Serv. Fish. Bull. 56:373-413.

Talbot, G.B., and J.E. Sykes. 1958.Atlantic coastal migrations ofAmerican shad. U.S. Fish Wildl.Serv. Fish. Bull. 58(142):473-490.

Walburg, C.H. 1957. Observations onthe food and growth of juvenileAmerican shad,.Alosa sapidissima.Trans. Am. Fish. sot. 86:302-306.

Walburg, C.H. 1960. Abundance andlife history of the shad, St.Johns River, Florida. 1J.S. FishWildl. Serv. Fish. Bull. 60(177):487-501.

Walburg, C.H., and P.R. Nichols. 1967.Biology and management of theAmerican shad and status of thefisheries, Atlantic coast of theIJnited States, 1960. U.S. FishWildl. Serv. Spec. Sci. Rep.Fish. 5!50:1-105.

18

b

REPORT DOCUMENTATION ;I. REPORT ~0.PAGE i Biol. Rep. 82(11.37)* i *.,

I I

4. nt1* and Subtitl. 5 R*Llorl oat*Species Profiles: Life Histories and Environmental Require- April 1985ments of Coastal Fishes and Invertebrates (Mid-Atlantic)-- aBmpriran shadr. Author(~) a Pe+anninc OrSanization Rept. hcc1. PWlOrminS OrSanlraWn Name and Address 10. ~mi9CI/Tash/Worh Unit No.Maine Cooperative Fishery Research Unit University of MaineU.S. Fish and Wildlife Service Orono, ME 04469 11. bnlr.Ct(C) or Grant(G) No.313 Murray Hall (C)

It tponrorlry O~~nix~tlon N8meand Addms - (G)

13. TYtm d R9p.M 6 Period covenNational Coastal Ecosystems Team U.S. Army Corps of EngineersFish and Wildlife Service Waterways Experiment StationU.S. Dep. of the Interior P.O. Box 631 14.Washington, DC 20240 . Vicksburg, MS 39180

*U.S. Army Corps of Engineers Report No. TR EL-82-4IL Abatnti Kimit: 200 words)

Species profiles are literature summaries on the taxonomy, morphology, distribution, lifehistory, and environmental requirements of coastal aquatic species. They are designed toassist in environmental impact assessment. The depleted populations of the Americanshad, Alosa sapidissima, are being restored in many of the rivers along the east coastthat originally supported large runs. The American shad is an anadromous fish that livesseveral years in the ocean and returns to its natal river to spawn in the spring whentemperatures reach 12 "C. The eggs are carried by ctirrents downstream from spawningsites in large rivers for 8-12 days until they hatch. The larvae, which metamorphose tojuveniles in 3-4 weeks, remain in the river until fall when they migrate to the sea.Shad move offshore and southward during winter at water temperatures of 3-15 "C.American shad feed on zooplankton. They adapt readily to fresh or saltwater, but theyprefer salinities exceeding 4 ppt.

EstuariesS h a d

GrowthFeeding

b. IdW.tlRen/O‘w,-Ended T.rmr

American shad Salinity requirementsAlosa sapidissima Temperature requirementsHabitat Spawning

Fisheries

C. COSATI Ficld/Gmup

i Ar8ilabllity Statwncnt

Unclassified

(Se. ANSl-239.lSl OPTIONAL FORM 272 M-77)(Formerly NTl%35)oep.rtment oi comm*re=

NWRC

This page has been left blank intentionally.

Species proiiies :kacicenz ie, Chet ,

s,esc wcn mvruryLJ. S. Department of the Interi’Yational Biological Surveyouthern Science Center

Eastern Energy and Land Use TeamLeetown. WV

National Coastal Ecosystems Team^. ~~I. .

w__ J 7 “-p--_c l---i

Western Energy and Land “se TeamFt Collins. CO

Locations Of RegIonal OffIces

REGION 1Regional DirectorU.S. Fish and Wildlife ServiceLloyd Five Hundred Building, Suite 1692500 N.E. Multnomah StreetPortland, Oregon 97232

REGION 4Regional DirectorU.S. Fish and Wildlife ServiceRichard B. Russell Building75 Spring Street, SW.Atlanta, Georgia 30303

REGION 2 REGION 3Regional Director Regional DirectorU.S. Fish and Wildlife Service U.S. Fish and Wildlife ServiceP.O. Box 1306 Federal Building, Fort SnellingAlbuquerque, New Mexico 87 103 Twin Cities, Minnesota 55 I I I

REGION 5Regional DirectorU.S. Fish and Wildlife ServiceOne Gateway CenterNewton Corner, Massachusetts 02158

REGION 6Regional DirectorU.S. Fish and Wildlife ServiceP.O. Box 25486Denver Federal CenterDenver. Colorado 80225

REGION 7Regional DirectorU.S. Fish and Wildlife Service101 I E. Tudor RoadAnchorage, Alaska 99503

DEPARTMENT OF THE INTERIORU.S. FISH AND WILDLIFE SERVICE

As the Nation’s principal conservation agency, the Department of the Interior has respon-sibility for most of our nationally owned public lands and natural resources. This includesfostering the wisest use of our land and water resources, protecting our fish and wildlife,preserving theenvironmental and cultural values of our national parks and historical places,and providing for the enjoyment of life through outdoor recreation. The Department as-sesses our energy and mineral resources and works to assure that their development is inthe best interests of ail our people. The Department also has a major responsibility forAmerican Indian reservation communities and for people who live in island territories underU.S. administration.