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VYNPS - SEIS Web Reference - Species Profiles-Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic) - American Shad
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Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic)

AMERICAN SHAD QL 155

.S63 no. 82 11.37 L L Fish and Wildlife Service U.S. Department of the Interior U.S. Army Corps of Engineers Coastal Ecology Group Waterways Experiment Station Biological Report 82(11~7)

April 1985 Library National Wetlands Reetaflh Center 11 c Ftsh and Wdllfe Sefllce 700 cajundome EWJ~

Lafayette, La. 70506 TR EL-824

This is one of the first reports to be published in the new "Biological Report" series.

This technical report series, published by the Research and Development branch of the U.S. Fish and Wildlife Service, replaces the "FWS/OBS" series'published from 1976 to September 1984. The Biolog-ical Report series is designed for the rapid publication of reports with an application orientation, and it continues the focus of the FWS/OBS series on resource management issues and fish and wildlife needs.

Biological Report 82(11.37)

TR EL-82-4 April 1985 Species Profiles:

Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic)

AMERICAN SHAD Chet MacKenzie Lori S. Weiss-Glanz and John R. Moring Maine Cooperative Fishery Research Unit 313 Murray Hall University of Maine Orono, ME 04469 Project Officer John Parsons National Coastal Ecosystems Team U.S. Fish and Wildlife Service 1010 Gause Boulevard Slidell, LA 70458 Performed for Coastal Ecology Group Waterways Experiment Station U.S. Army Corps of Engineers Vicksburg, MS 39180 and National Coastal Ecosystems Team Division of Biological Services Research and Development Fish and Wildlife Service U.S. Department of the Interior Washington, DC 20240

This series should be referenced as follows:

U.S. Fish and Wildlife Service.

1983-19 Species profiles:

life histories and environmental requirements of coasts fishes and invertebrates.

U.S. Fish Wildl. 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:

life histories 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 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 one of the following addresses.

Information Transfer Specialist National Coastal Ecosystems Team U.S. Fish and Wildlife Service NASA-Slide11 Computer Complex 1010 Gause Boulevard Slidell, LA 70458 or U.S. Army Engineer Waterways Experiment Station Attention:

WESER-C Post Office Box 631 Vicksburg, MS 39180 iii

Multiply BY To Obtain millimeters (mn) 0.03937 inches centimeters (cm) 0.3937 inches meters (m) 3.281 feet kilometers (km) 0.6214 miles square meters (m2) _

square kilometers (km) hectares (ha) 10.76 square feet 0.3861 square miles 2.471 acres liters (1) 0.2642 cubic meters (m3) gallons 35.31 cubic feet cubic meters 0.0008110 acre-feet milligrams (mg) 0.00003527 ounces grams (9) 0.03527 ounces kilograms (kg) 2.205 pounds metric tons (t) 2205.0 pounds metric tons 1.102 short tons kilocalories (kcal) 3.968 British thermal units Celsius degrees 1.8("C) + 32 Fahrenheit degrees inches 25.40 millimeters inches 2.54 centimeters feet (ft) 0.3048 meters fathoms 1.829 meters miles (mi) 1.609 kilometers nautical miles (mii) 1.852 kilometers square feet (ft')

acres square miles (mi2) 0.0929 square meters 0.4047 hectares 2.590 square kilometers gallons (gal) 3.785 liters cubic feet (ft3) 0.02831 cubic meters acre-feet 1233.0 cubic meters ounces (oz) pounds (lb) short tons (ton)

CONVERSION TABLE Metric to U.S. Customary U.S. Customary to Metric 28.35 0.4536 0.9072 British thermal units (Btu) 0.2520 Fahrenheit degrees 0.5556("F iv 32)

Celsius degrees grams kilograms metric tons kilocalories

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 iii iv vi 1

1 3

3 3

4 5

6 6

7 7

7 10 11 11 12 12 12 12 12 13 13 13 13 13 15

ACKNOWLEDGMENTS The authors thank Christine M. Moffitt, Idaho Cooperative Fishery Research

Unit, University of Idaho; Richard J. Neves, Virginia Cooperative Fishery Research Unit, Virginia Polytechnic Institute and State University; and Roy W.

Miller, Division of Fish and Wildlife, Dover, Delaware, for reviewing portions of the manuscript.

vi

Figure 1.

The American shad.

AMERICAN SHAD NOMENCLATURE/TAXONOMY/RANGE Scientific name.. Alosa sapidissima (Wilson)

Preferred common name

... American shad (Figure 1).

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

Class Osteichthyes Order Clupeiformes Family.

Clupeidae Geographic range:

American shad are anadromous.

They are distributed along the Atlantic coast from New-foundland to Florida, and are most abundant from Connecticut to North Carolina.

In the mid-Atlantic region the American shad ascend essentially all major rivers, but abundance in some rivers is limited by pollution or restricted by dams (Figure 2).

On the Pacific coast, the American shad was introduced into the Sacramento and Columbia Rivers in 1871, and the species is now established from southern California northward to Cook Inlet, Alaska, and the 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 Schroeder 1953; Scott and Crossman 1973). Head broadly triangular, 22%-24% of TL.

Gill membranes free from isthmus. Eye

moderate, adipose e.yelid well devel-oped, diameter of eye 27%-32% of head length (HL);

snout moderate, length 27%-32% HL; interorbital width 19%-22%

of HL.

The anterior end of the lower jaw not especially thick or heavy and somewhat pointed, and fitting easily into a deep notch in upper jaw so that the jaws are about equal when the mouth is closed.

The upper outline of the lower jaw slightly concave. Maxil-lary extending to posterior margin of eye.

Teeth small, weak, and few in 1

NEW YORK PHILADELPHIA ATLANTIC OCEAN 3e N

I M I L E S OV KILOMETERS NORTH CAROLINA CAPE HATTERAS Figure 2.

American shad are distributed along the coast of the Mid-Atlantic Region from Massachusetts to North Carolina, but are most abundant in this region along the coast from Connecticut to North Carolina.

They ascend essentially all major rivers but may be limited in some rivers by pollution or restricted by dams.

2

number on premaxillary and mandible (lost completely in the adult) and ab-sent on the roof of the mouth.

Gill rakers on lower limb 59-73; branchio-stegal rays 7,7 (rarely 7,6).

Fins soft rayed: dorsal-l, height moderate, base short, ll%-13% of TL, rays 15-19, usual1.y 17-15;

caudal, forked; anal-l, distinctly than dorsal base length greater

base, 13%-14% of TL, height shorter than dorsal rays 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, crenulate on posterior

margin, deciduous.

Lateral line poorly developed with about 50-55 scales.

Ventral scutes well developed forming a sharp saw-belly, prepelvic scutes 19-23, usually 20-22, postpelvic scutes 12-19, usual-ly 15-17.

55-58.

Vertebrae 53-59, usually Peritoneal lining pale; pylor-ic caeca numerous and usually c,luster-ed on right side.

Usually 4 to 6 black spots in horizontal row behind operculum.

Size: average total length 380 mm; males up to 2.7 kg; females up to 3.6 kg, rarely to 5.4 kg.

REASON FOR INCLUSION IN THE SERIES Historically, commercial fishing for American shad on the Atlantic coast has been intensive and wide-spread.

Now the fishery has virtually collapsed and is important only in a few 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 strong

runs, sport fishing for shad is more important than commercial fishing.

Federal and State agencies have initiated management programs aimed at restoring American shad to their former range and abundance.

The American shad is a natural resource that should be considered for protection in coastal and riverine development projects.

LIFE HISTORY Spawning The American shad is an anadro-mous fish that lives several years in the ocean and then returns to its river of origin to spawn.

At one time, the species probably spawned in virtually every accessible river and tributary along the Atlantic coast of North America.

The freshwater spawning migration in winter, spring, or summer is timed to correspond to favorable river water temperatures.

Shad usually migrate far enough upstream so that the eggs drift downstream and hatch before reaching saltwater.

In one study in the Connecticut

River, low river temperatures may have delayed the maturation of gonads causing the shad to migrate farther upstream to spawn (Marcy 1976).

Glebe and Leggett (1981) reported that the gonads of American shad mature prior to entering the Connecticut River.

American shad spawn as early as mid-November in Florida and as late as July in some Canadian rivers.

Males arrive at the spawning grounds before females (Chittenden 1975).

Water temperature is the primary factor that triggers

spawning, but photoperiod, flow velocity, and water turbidity also exert some influence (Leggett and Whitney 1972).

Although shad eggs in Virginia streams become abundant after the water temperature reach 12°C (Massman 1952),

most spawning is from 13" to 20°C (Walburg and Nichols 1967). In North Carolina, peak spawning is at water temperatures near 20°C (Sholar 1976).

The diameter and abundance of shad eggs collected in plankton nets in the Pamunkey

River, Virginia, indicate that spawning takes place at all hours of the night and day but is 3

more intense from noon to midnight (Massman 1952).

According to Miller et al. (1971, 1975), spawning begins in the evening between 1900 h and 2000 h and peaks between 2100 h and 2300 h in the Delaware River.

After 0100 n, most of the spawning subsides.

On overcast days, spawning begins earlier than on clear days, which supports the hypothesis that the daily onset of spawning is regulated by light intensity (Miller et al. 1982).

Group spawning involving several males and a female has been observed (Marcy 1972).

The spawning fish swim vigorously at the surface, forming a closely packed circle.

Eggs are released into the water and then fertilized by the males (Marcy 1972; Scott and Crossman 1973).

Shad spawn in main streams of North Carolina rivers over sand shoals where there is sufficient current to keep the eggs suspended in the water column (Sholar 1976). Shad spawn over sand, silt, muck, gravel, and boulder substrates (Mansueti and Kolh 1953; Walh?rrg 1960; Leggett 1976).

They spawn in water depths about 1 to 10 m (3 to 30 ft) but most often less than 3 m (10 ft)

(Walburg and Nichols 1967).

The current in spawning areas ranges from about 0.5 to 3 ft/s (Walburg and,Nichols 1967; Marcy 1972).

The percentage of shad that spawn more than once increases from south to north (Table 1). For example, shad in rivers south of Cape Fear, North

Carolina, die after spawning, but in more northerly rivers some shad survive spawning to spawn again.

Shad may return to spawn for up to 6 years (Table 2).

The percentage of repeat spawners ranges from 0% for the St. Johns River, Florida, south of Cape Fear, North Carolina, to 73% in the St. John River, New Brunswick (Carscadden and Leggett 1975a, 1975b).

The Delaware River, unlike other mid-Atlantic coast shad rivers, has few repeat spawners (1.5%

to 6.5%)

Table 1.

The percent of repeat spawners in American shad spawning runs in 4tlantic coast rivers (Leggett and Carscadden 1978).

River and Latitude Repeat location of river

("N) spawners(%)

Miramichi (NB) 49 64 St. John (NB) 45 73 Connecticut (CT) 41 63 Hudson (NY) 41 57 Delawarea (DL) 40 6

Susquehanna (VA) 40 37 Potomac (VA) 38 20 York (VA) 37 24 James (V4) 37 27 Neuse (NC) 35 3

Edisto (SC) 33 0

Ogeechee (GA) 32 0

St. Johns (FL) 30 0

-___~

a Chittenden (1975).

according to Chittenden (1975). He suggests that the probable causes for the scarcity of repeat spawners there are pollution and overfishing.

Fecundity and Ew The American shad has a rela-tively high fecundity (116,000 to 659,000 eggs per female; Table 2).

Many eggs fail to fertilize and only a small percentage of the fertilized eggs hatch.

High egg mortality has been attributed to failure to fer-

tilize, suffocation, fungus infection, and predation (Leach 1925; Mansueti and 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 irregularly round in form and are about 1.8 mm in diameter; fertilized, waterhardened eggs 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 the United States, 1951-1959 (Walburg and Nichols 1967).

-~

Range of Fork Body Age number of eggs River length (mm) weight (kg)

(years) per female (x 1,000)

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

368-460 0.6-1.8 4-6 277-659 Table 3.

Mean virgin (first time spawners) and lifetime fecundities of American shad populations from five Atlantic coast rivers, 1958-1973 (Leggett and Carscadden 1978).

Virgin Lifetime River fecundity fecundity St. Johns (FL) 406,000 406,000 York (VA) 259,000 327,000 Connecticut (CT) 256,000 384,000 St. John (NB) 135,000 273,000 Miramichi (NB) 129,000 258,000 are transparent, pale pink, or amber (Marcy 1976; Miller et al. 1982).

Fertilized eggs are slightly heavier than water and are nonadhesive.

The rate of development of shad eggs is linearly related to temperature (Mansueti and Kolb 1953). Eggs hatch in 8 to 12 days at 11" to 15°C: 6 to 8 days at 17°C; and 3 days at 24°C (Bigelow and Schroeder 1953; Scott and Crossman 1973).

No viable eggs develop at water temperatures above 29°C (Bradford et al. 1966).

Larvae to Adults American shad yolk-sac larvae are about 6 to 10 mm long (TL) at hatching and 9-12 mm TL when the egg yolk is absorbed (Marcy 1976).

Initially the larvae 9-27 mm TL are planktonic (Mansueti and Hardy 1967; Jones et al.

1978).

They reach the juvenile stage when about 25 to 28 mm long and about 4 weeks old (Jones et al. 1978).

Juveniles spend the first summer in the river feeding on crustaceans and aquatic insects at the surface or in the water column (Leim 1924: Walburg 1957; Levesque and Reed 1572).

In the fall, juveniles (75 to 125 mm long) migrate down the rivers to brackish water and then to the sea. A decrease in river water temperature seems to trigger the migration (Chittenden 1972).

Juvenile shad migrate seaward first in northern rivers southern a n d progres;~v;~ttlater rivers Juvenile shad leave the St.

1977;:

Johns River, Florida, as the water cools to 15.5OC (Walhurg 1960).

In the Delaware

River, shad begin moving downstream when the water temperature drops to about 20°C; the movement peaks at 15°C (Sykes and Lehman 1957).

In the Connecticut River, downstream migration peaks late in September and October.

Peaks for the Upper Delaware River and the Chesapeake Bay arc? late October and late November, respect-ively.

Once in the ocean, the shad remain there until they mature.

5

Males become sexually mature when they are 3 to 5 years old and the females mature at 4 to 6 years old (Leim 1924).

Most of the male first-time (virgin) spawners in the Neuse (North Carolina) and Susquehanna (Maryland) Rivers are 4 years old (LaPointe 1958).

The majority of female virgin spawners are 4 to 5 years old.

Shad are known to complete their entire life cycle in only one freshwater system: Millerton Lake, a reservoir on the San Joaquin River, California (Lambert et al. 1980).

Morphological characteristics for distinguishing shad larvae from other larvae of similar species are described by Jones et al, (1978).

Ocean Migration-The American shad in the mid-Atlantic region form large schools and undertake extensive ocean migration (Leggett and Whitney 1972). Shad from all Atlantic coast rivers spend the summer and fall in the Gulf of Maine (Talbot and Sykes 1358).

This congregation includes immature shad and spawned-out adults from rivers north of Chesapeake Bay.

Shad are apparently scattered along the mid-Atlantic coast during the winter (Talbot and Sykes 1958; Walburg and Nichols 1967).

Migrating American shad seek bottom water temperatures between 3" and 15°C but probably prefer temperatures between 7" and 13°C (Neves and Depres 1979).

In early spring, the schooyho;z shad migrate toward the coast.

returning to rivers south of Cape Hatteras follow the Gulf Stream t o remain within the 3" to 15'C bottom isotherm.

Those migrating to rivers north of Cape Hatteras later in the spring follow a route farther seaward into the Middle Atlantic Bight where water temperatures have risen sufficiently.

Tag returns indicate that some schools migrate north along the coast (Neves and Depres 1979).

American shad migrate as much as 21 km/day in Chesapeake Bay andsot:;

Bay of Fundy (Leggett 1977).

migrate iup to 3,000 km during the spring or fall migration.

A large majority of American shad return to their natal river to spawn.

Homing behavior involves both olfac-tion and rheotaxis (Dodson and Leggett 1974).

The homing mechanism is sufficiently robust to perpetuate migrations even after major changes in water

flow, such as below a

hydroelectric dam.

GROWTH CHARACTERISTICS American shad live to be 5 to 7 years old and most weigh between 1 to 3 kg.

The oldest shad reported for the United States was 11 years of age and 584 mm long (Scott and Crossman 1973).

Factors that affect growth sometimes can be identified by examining fish scales.

Slow growth in the winter causes growth rings on scales to be close together; these winter marks (annuli) can be used to age fish.

Judy (1961) verified the scale method for aging American shad.

He also noted a mark on the scales that formed when the juveniles left fresh water, and described marks that formed at spawning.

Shad grow about 100 mmlyr until sexually mature; after maturity, growth slows (Table 4).

Table 4.

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

Growing Season _

Age Length Increment 1st I

120 2nd II 240 120 3rd III 320 80 4th IV 400 80 5th V

470 70 6th VI 520 50 7th VII 570 50 6

THE FISHERY History In the 19th century, extensive fisheries for shad developed along the entire Atlantic coast from the St.

Johns River,

Florida, to the St.

Lawrence River, Canada.

Major types of gear were drift and staked gill nets, pound nets, haul seines, weirs, fyke nets, bow nets, and dip nets.

The estimated U.S. Atlantic coast catch in 1896 was 22,680 metric tons (50 million lb).

Between 1930 and

1960, the average annual catch was about 4,530 metric tons or 10 million lb (Figure 3).

In 1983, landings were about 1,585 metric tons (3.5 million lb).

Commercial shad landings in Chesapeake Bay were traditionally the largest along the Atlantic coast (Table 5), but because of the closure of Maryland's shad fishery in 1980, the mid-Atlantic and South Atlantic catches have been greater.

Dams, pollution, and overfishing have contributed to the decline of shad stocks.

Current Statistics Rhode Island.

American shad are an incidental part of the commercial catch in Rhode Island.

Approximately 77,000 lb were landed in 1982 (Table 6).

The Runnings and Warren Rivers support a small sport fishery. Shad AMERICAN SHAD - U.S. ATLANTIC COAST 25000 -

Figure 3.

Landings of American shad, U.S. Atlantic coast, 1880-1976 (Walburg oermission from Public Service and 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 regions along 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 Marine Fisheries Service, Statistical Digest; 1978-83, National Marine Fisheries

Service, unpublished data).

Year NE Coastal regions MA CB SA PC 1960 432 1,237 2,682 1,614 456 1961 547 1,026 3,144 1,612 927 1962 470 841 3,795 2,167 1,586 1963 325 744 3,139 1,734 1,503 1964 320 721 3,541 1,687 818 1965 380 635 4,298 2,379 870 1966 279 379 3,564 1,736 1,347 1967 754 387 3,005 1,562 1,333 1968 218 379 3,508 2,052 862 1969 201 342 3,540 1,904 610 1970 186 314 5,151 1,851 724 1971 283 222 2,473 1,452 499 1972 264 375 3,014 1,091 709 1973 261 308 3,033 685 483 1974 257 294 1,789 655 511 1975 208 337 1,321 518 522 1976 412 322 1,006 320 481 1977 418 394 1,547 418 560 1978 361 245 1,322 976 545 1979 330 216 1,041 363 797 1980 253 406 998 839 277 1981 66 510 500 1,235 120 1982 403 757 590 1,033 429 1983 504 365 242 1,974 413 have been reintroduced unsuccessfully in the Pawcatuck River, in an attempt to restore a spawning population there; the river is currently closed to shad fishing.

Connecticut.

The Connecticut River supports a modest commercial shad fishery.

Most fishing is with drift gill nets below Hartford at night.

Some fishing is done during the day when the water is turbid.

Fyke, trap, and pound nets are not allowed in the river during the shad run.

The primary market is for roe (eggs); males (buck shad) have little or no value.

The State of Connecticut carefully regulates commercial fishing for shad on the Connecticut River.

The season is open to commercial fishing from April 1 to June 15.

During the

season, fishing is prohibited from Friday sunset to Sunday sunset.

Monofilament gill nets are prohibited and the gill nets used must have a minimum stretch Imeasure of 5 inches.

There are no size or sex restrictions.

License holders must report their catch at the end of each fishing season.

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

Table 6.

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

Year 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 Rhode Island 3

4 7

2 3

4 23 5

2 6

12 42 14 2

7 6

3 1

1 1

2 1

77 23 Connecticut 421 463 456 301 278 352 242 240 212 190 173 241 249 258 247 165 392 392 332 306 207 325 283 424 New New York Jersey 472 694 303 633 243 480 202 442 141 430 133 392 ai 242 113 248 126 241 136 188 106 195 73 141 103 263 157 143 164 122 196 122 186 100 1

194 2

160 a

148 114 292 58 259 73 334 33 112 Mary1 and 1,336 1,815 1,575 a27 890 1,343 1,133 867 958 1,292 1,039 953 957 597 220 184 110 77 a7 47 24 1

9 27 North Carol ina 702 673 765 693 640 1,069 701 777 a42 719 953 680 468 321 369 241 167 120 402 278 199 352 412 380 Angling and scoop nets are permitted in streams.

The daily bag limit is six fish.

New York.

The Hudson River has the only commercial American shad fishery of note in New York.

Gill nets are the principal type of commercial gear used.

Staked gill nets contribute about 70% of the gill net catch and drift gill nets contri-bute 30%.

New Jersey.

Most commercial fishing (almost entirely with gill nets) in New Jersey is concentrated in Delaware Bay; there is no sport fishery in the bay.

The only sport fishery begins about 90 mi up the Delaware River near Trenton, New Jersey.

Shad from the Delaware River have been stocked into the Raritan 9

River basin in an attempt to restore the once abundant runs there:, however, all attempts of restoration have failed (Didun 1983).

Pennsylvania.

There is no com-mercial fishery for American shad in Pennsylvania, but major restoration attempts are underway on the Susquehanna and Schuylkill Rivers where sport fishing for shad is currently banned.

The estimated annual value of the sport fishery on the Schuylkill River fishery will be

$1,200,000 if the goal of restoration is achieved (Mulfinger and Kaufmann 1980).

Estimates of the annual value of the current sport fishery on the upper Delaware River range from

$828,000 to $3,000,000 (Miller et al.

1982).

Delaware.

The legal commercial gear in Delaware is 5-to 6-inch (stretch measure) gill nets. Fishing is allowed from March until early May.

In the past 30 years, the fishery has shifted from the lower Delaware

River, where drift gill nets were used, to Delaware Ray, where anchored gill nets predominate (Miller 1982).

The increase in the commercial catch of American shad in the Delaware Estuary in recent years gives some evidence that the species is becoming more abundant (Table 7).

The increase is attributed partly to recently completed pollution abatement projects in the lower Delaware River (Miller 1982).

There is no sport fishery except for Nanticoke River and Broad

Creek, tributaries to Chesapeake Bay.

The fishing season for the Delaware waters of the Delaware Estuary is from June 10 to February 1.

Maryland.

A sharp decline in the commercial catch of American shad in Maryland began in 1973 (Table 6).

This led to the closing of all waters in varyland to shad fishing with the exception of the Potomac River (which is regulated by the Potomac River Fisheries Commission) and coastal waters (Carter and 'rleinrich 1982).

Table 7. American shad catch (x 1,000 lb) and value (x 1,000 dollars) for Delaware and Virginia (Miller 1982; Jack Travelstead, Virginia Marine Resources Commission; pers.

comm.).

Date Delaware Virginia Catch Value Catch Value 1960 38 6

1.349 234 1965 110 16 21955 307 1970 13 1

4,112 315 1975 19 4

1,137 309 1976 36 8

896 284 I977 75 15 1,469 498 1978 70 20 1,235 212 1979 95 15 994 235 1980 1;;

31 974 353 1981 87 499 141 1982 333 585 180 Virginia.

The biggest American shad fishery is along the Atlantic coast of Virginia.

In 1982, 585,000 pounds were landed with a value of

$180,028 (Table 7). Gill nets are the primary gear used.

North Carolina.

In North

Carolina, shad are caught by commer-cial and sport fishermen from late January to the end of March.

The commercial fishery employs drift and staked gill

nets, pound nets, and seines.

The primary types of gear used on the Neuse River, which has the largest commercial

catch, are staked and drift gill nets (Hawkins 1980).

Population Dynamics

_~

Recruitment into the shad fishery is largely dependent on the size of the spawning stock and environmental factors that govern spawning success and survival.

About 85% of the variation in the numbers of American shad that spawn in the Hudson River in any one year is largely dependent on the number of spawners 5, 4, and 1 year earlier (Talbot 1954). About 64%

of the annual variation in the abun-dance of juvenile shad in the Connecticut River from 1966 to 1973 was directly related to the number of spawners; 22%

was attributed to environmental

factors, principally water temperature and river flow during the run (Marcy 1976).

The rate of exploitation is a major factor influencing changes in the abundance of shad in the Connecticut River (Leggett 1976).

Because of the high value of shad eggs (roe), females in the spawning run are the main targets of the fishery.

The number of adults that survive the fishery in any one year is directly correlated with the numbers of fish produced in the next generation.

This relationship is described by a

stock-recruitment equation:

10

q = N 0.7 (I - N/87) e where R is recruitment and N is the parent stock in terms of egg numbers (Leggett 1976).

Average annual mortality

rates, calculated from tag-recaptures data, were about 70%

for males and 71% for females from 1965 to 1973 in the Connecticut River (Leggett 1976).

The age structure of American shad returning to spawn in Delaware and North Carolina consists primarily of 4-and 5-year-old males and 5-and 6-year-old females (Table 8).

ECOLOGICAL ROLE Foods Apparently, young American shad in rivers feed mostly in the water b

column (Levesque and Reed 1972; Domermuth and Reed 1980).

Early shad larvae feed mostly on cyclopoid copepods and tendipedids (Levesque and Reed 1972).

The stomach contents of Table 8.

Age composition (%) of the spawning population of American shad Delaware

Fhitttheenden

River, Delaware 1975),

and the Neuse River, North Carolina (Hawkins 1980).

Delaware North Carolina Age Number Age Number II III IV V

VI IV V

VI VII Males 00 2'6 236 76:l 62 20.0 3

0.0 Females 225:

61.6 13.7 88 24.1 2

0.0 Males III 16 IV 126 3;

V 151 46 VI 310 9

VII 3

1 Females IV V

444:

5:

VII 10 1

VIII 1

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

A!hns, Florida;

Ogechee, Georgia;

Neuse, North Carolina;

Pamunkey, Virginia;

Hudson, New York; Connecticut, Connecticut) suggested that shad ate suitable organisms that were most available (Walburg 1957).

In contrast, a study performed on the Connecticut

River, Connecticut, by Domermuth and Reed (1980) demonstrated that juvenile shad (Tl =

28 to 132 mm x = 63.3 mm) were selective; i.e.,

most selected daphnia (51%) and bosmids (20%), whereas despite high abundance, copepods (8%)

and benthos (0.1%) were consumed in small quantities.

After going to sea, juveniles and adults feed on a variety of small crustaceans, many of which are benthic organisms.

Copepods and mysids constituted 90% of the diet of adult shad in the Bay of Fundy (Leim 1924).

Adults also feed on small fishes, euphausids, fish eggs, and amphipods (Bigelow and Schroeder 1953; Scott and Crossman 1973).

Most shad have a die1 vertical migration that follows the die1 migration of their principal

food, zooplankton (Neves and Depres 1979).

In a study off the coast of North

Carolina,

'anchovies (Anchoa hepsetus) were in 12 of the 15 juvenile shad examined (87-141 mm),

and 39 of 41 adults (Holland and Yelverton 1973).

The stomachs also contained zooplankton under 5

mm (Holland and Yelverton 1973).

This size was reported by Atkinson (1951) as being too small for shad gill rakers to retain.

Food was scarce in the stomachs of shad migrating upstream to spawn (Leim 1924).

But in one experiment, migrating prespawning shad placed in a freshwater pond fed on artificial feed (Atkinson 1951).

Adult shad fed on mayflies in freshwater and their stomachs contained the remains of small fish (Chittenden 1976).

Shad strike; 11

artificial lures when in freshwater, a behavior unexplained.

Predators Juvenile shad may be preyed upon by a variety of predators in fresh-waters (Scott and Crossman 1973), but Leim (1924) was unable to demonstrate predation by either American eels (Anguilla rostrata) or striped bass (Morone sax-in the Shubenacadie River, Nova Scotia.

Seals prey on American shad, but adults probably have few enemies, except for humans (Scott and Crossman 1973).

Diseases The American shad has the usual complement of parasites and diseases.

Acanthocephala, parasitic

copepods, distomes, nematodes, and trematodes have all been reported in or on shad (Scott and Crossman 1973). In the Connecticut River, the sea lamprey (Petromyzon marinus) and freshwater lampreys (Ichthyomyzon spp.) sometimes attach to adult shad (Walburg and Nichols 1967).

ENVIRONMENTAL REQUIREMENTS Salinity The American shad adapts readily to either freshwater or seawater during its anadromous migrations. The adults may spend two to three days in the estuary before entering the river (Leggett 1976).

One test was made in this connection.

Transfer of adult shad from seawater to freshwater over a 2.5 hour5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months period caused physiologic stress and a mortality of 54% (Leggett and O'Boyle 1976).

Eggs are always deposited in freshwater and are believed to be intolerant of full-strength seawater.

Leim (1924) suggests that shad eggs and larvae tolerate brackish water with 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 the Pacific and Atlantic coasts of North America peak at water temperatures of 15.5' to 2O.O"C (Leggett and Whitney 1972).

The rate of development of shad linearly related

~~$erat~~e (Mansueti and Kolh,953;:

Eggs hatch in 8 to 12 days at 11' to 15°C; 6 to 8 days at 17C and 3 days at 24°C.

(Leim 1924; Bigelow and Schroeder 1953; Scott and Crossman 1973).

E!w stop developing when water temperatures drop to 7°C (Leim 1924).

Abnormalities develop when the temperature rises to 22OC (Leim 1924),

and no viable larvae develop from eggs at water temperatures above 29°C (Bradford et al. 1966).

The American shad is intolerant of cold water temperatures.

The lower thermal tolerance limit is about 2°C but prolonged exposure to 4" to 6°C may cause high mortality or stress (Chittenden 1972). If young shad are given a choice, they generally avoid temperatures below 8°C and strongly avoid temperatures below 5°C.

Chittenden concluded that cold water releases below large impoundments may curtail or destroy historical spawning and nursery areas there.

Juvenile American shad attempt to avoid excessively high or rapid increases in water temperature.

Tests in tanks show that shad avoid temperature increases of about 4°C above the acclimation temperature (Moss 1970).

They did not attempt to avoid changes of l"C, suggesting a sensory threshold of between +l" and

+4"C above ambient temperature.

Field observations bear out the laboratory findings of Chittenden (1972) and Moss (1970). Migrations of 17

American shad in the ocean and freshwater are closely tied to changes in vfater temperature.

Shad are most frequently caught commercially in ocean bottom temperatures of 7' to 13°C (Neves and Depres 1979).

Oxygen The American shad require well-oxygenated waters either in rivers or in the sea.

Dissolved oxygen levels must be at least 4 to 5 mg/l in headponds through which shad pass in their migration (Jessop 1975). In the laboratory, equilibrium is lost at dissolved oxygen levels below 3 mg/l; heavy mortality occurs at :evels below 2 mg/l; and all fish die at concen-trations less than 0.6 mg/l (Chittenden 1969).

Shad eggs were absent where the concentration of dissolved oxygen was lower than 5 mg/l (Marcy 1976).

The oxygen LCso for Connecticut River shad eggs is 2.0 to 2.5 mg/l (Carlson 1968).

Turbidity Extensive dredging of the Hudson River produced no measurable adverse effects on shad abundance (Talbot 1954).

Adult shad readily enter the Shuebenacadie River in Nova Scotia, where suspended sediment concentration sometimes is 1 g/l (Leim 1924). In a laboratory study, mortality of eggs held in concentrations of suspended sediments up to 1 g/l from fertiliza-tion to hatching did not differ significantly from control groups (Auld and Schubel 1978); however, the survival of shad larvae exposed to concentrations greater than 0.1 g/l for 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months was sharply reduced.

Larvae apparently are much less tolerant of suspended sediments than eggs.

Substrate Substrate type apparently is unimportant to shad.

They spawn in the water column and the eggs are carried 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).

Only under the most adverse of conditions, in which mud covered and smothered the eggs, was substrate a problem.

Depth American shad show little depth preference in freshwater.

Adults are caught during spawning runs in all parts of the river channel.

Spawning has been observed in rivers at depths ranging from 0.45 to 7 m (Mansueti and Kolb 1953; Walburg 1960; Kuzmeskus 1977).

Juveniles were found at depths of 0.9 to 4.9 m in the Connecticut River (Marcy 1976).

Abundance was related to the distance upstream and not to depth.

During the day, 87% of the juvenile shad caught in a gill net

req ;e",' the bottom at depths of 3.7 At night, all were caught near the surface. At sea, shad are near the bottom during the day and disperse in the water column at night (Neves and Depres 1979).

Water Hovement Water velocity is critical to shad because shad must negotiate river currents and occasional fishways when migrating upstream, and pass safely over spillways while going downstream.

Adult shad migrating upstream are reluctant to use traditional fishways, probably because entrance widths,

depths, and flows are often unsuitable (Walburg and Nichols 1967). Pool-and-weir

fishways, vertical-baffle

fishways, and elevators are better carriers of American shad.

For the pool-and-weir fishway, optimum differ-ence in pool elevations is 23 cm when water velocities are 61 to 91 cm/set.

For any fish passage to work, proper current at the entrance is essential.

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

.3

in brackish water, and 14 km in fresh-water (Leggett 1976).

Adult downstream migration depends on water currents and the pattern of currents around obstructions.

In the Farmington River, a tributary of the Connecticut River, flow rate into the fishway accounts for 60%

of the variation in the number of downstream migrants entering the fishway (Moffitt 1979).

No fish entered the tributary because of the lack of an adequate attractant flow.

Fish that fail to find the downstream passage must pass over the spillway or through hydroelectric turbines.

Between 57%

and 80% of juvenile shad that pass through a 850 kw Ossberger turbine are killed outright, and others may die later of stress or are easy prey to predators (Gloss 1982). A fishway may cause mortality because of excessive loss of scales and injury.

At least 25% of the shad die as a result of the fish-lift at Mactaquac, New Brunswick (Jessop 1975).

Exposure to lethal nitrogen supersaturated waters below the dam sometimes causes stress or mortality (MacDonald and Hyatt 1973).

Spawning takes place in water velocities ranging from 9.5 to 132 cm/set based on hydrographic data at sites where Kuzmeskus (1977) found fresh spawn.

Spawning normally takes place at velocities of 30 to 90 cm/set (Walburg 1960).

14

LITERATURE CITED Atkinson, C.E. 1951.

Feeding habits of shad (Alosa sa idissima) in fresh water.

--4__T Ecology 32 3):556-557.

Auld, A.H., and J.R. Schubel. 1978.

Effects of suspended sediment on fish eggs and larvae, a labora-tory assessment.

Estuarine Coastal Mar. Sci. 6(2):153-164.

Bigelow, H.B., and W.C. Schroeder.

1953.

Fishes of the Gulf of Maine. U.S. Fish Wildl. Serv.

Fish. Bull. 53. 577 pp.

b Bradford, A.,

J. Miller, and K. Buss.

1966.

Bio-assays on eggs and larval stages of American shad (Alosa sapihissima). Pages 52-60 in. Carlson.

ae Suitability of Susquehanna River for restoration of shad.

U.S. Dep.

Inter.,

Bur. of Sport Fish. and Wildl.

Washington, @.C.

Carlson, F.T.

1968.

Suitability of the Susquehanna River for the restoration of shad. U. S. Dep.

Inter., Bur. Sport Fish.

and Wildl. Washington, D.C. 60 pp.

Carscadden, J.E., and W.C. Leggett.

1975a.

Meristic differences in spawning populations of American shad, Alosa sapidissima: evidence for homto tributaries in the St. John River, New Brunswick. J.

Fish. Res. Board Can. 32(5):653-660.

Carscadden, J.E., and W.C. Leggett.

1975b.

Life history variations in populations of American shad, Alosa sapidissima (Wilson),

spawning in tributaries of the St. John River, New Brunswick. J.

Fish Biol. 7(50):595-609.

Carter, W.R., III, and D. Weinrich.

1982. An overview of Maryland's shad stocks. Tidal Fish. Div.,

Md. Dep. Nat. Resour. 52 pp.

Chittenden, M.E., Jr. 1969. Life his-tory and ecology of the American

shad, Alosa sa idissima

% TihnesF?

DelawareTRi;ver.

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

Chittenden, Y.E.,

Jr. 1972.

Responses of young American shad, Alosa sapidissz, to low temperatures.

Trans. Am. Fish. Sot. lOl(4):

680-685.

Chittenden. M.E.. Jr. 1975. Dvnamics of 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.

Weight loss, 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 feasibility of reestablishing American shad, (Alosa sap_idissima):

Raritan Basinanadromous 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 in the behavior of American shad (Alosa sapidissima) homing to the Connecticut River from Long Is-land Sound. J. Fish. Res. Board Can. 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 River below Holyoke Dam, Massachusetts.

Estuaries 3(1):65-68.

Glebe, B.D., and W.C. Leggett. 1981.

Temporal, intra-population dif-ferences in energy allocation and use by American shad (Alosa sapidissima) during the spawning migration. 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 at low-head hydropower sites. Page 22 in R.G. Howey, ed. Proceedings of 1981 American shad workshop --

culture, transportation and marking. U.S. Fish Wildl. Serv.

Lamar Infor. Leafl. 82-01.

Hawkins, J.H. 1980. Investigations of anadromous fishes of the Neuse

River, North Carolina.

Spec.

Sci. Rep.

No. 34. N.C. Dept. of Natur. Resour. Dev. 111 pp.

Holland, B.F. Jr.,

and G.F. Yelverton.

1973. Distribution and biological studies of anadromous fishes offshore North Carolina. Spec.

Sci. Rep. No. 24. N.C. Dep. Nat.

Econ. Resour. 132 pp.

Jessop, B.M. 1975.

A review of the American shad (Alosa sapidissima) stocks of the St. John River, New Brunswick, with particular refer-ences to the adverse effects of hydroelectric 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 of fishes of the Mid-Atlantic Bight.

Pages98-104 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 age determinations from scales of marked American shad. U.S. Fish Wildl. Serv. Fish. Bull. 61:16I-170.

Kuzmeskus, D.M. 1977.

Egg production and spawning site distribution of the 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 with soawnino of a landlocked American shad, Ajosa sa idissima, popula-tion.

Am. -%X--20(4):813.

(Abstr.)

La Pointe, D.F. 1958. Age and growth of the American shad, from three Atlantic coast rivers, Trans. Am.

Fish. Sot. 87:139-150.

Leach, G.C.

1925.

Artificial propagation of shad.

Pages 459-486 in U.S. Bur. Fish. Docket Number 981, App. VIII, Rep. U.S.

Comm. Fish., 1924.

Leggett, W.C. 1976.

The American shad (Alosa sapidissima), with special reference to its migra-tion and population dynamics in the Connecticut River. Am. Fish.

Sot. Monogr. No. 1:169-225.

Leggett, W.C. 1977.

Ocean migration rates of American shad (Alosa 16

sa idissima). J. Fish. Res. Board Ci!hTpp422-1426.

Leggett, W.C., and J.E. Carscadden.

1978.

Latitudinal variation in reproductive characteristics of American shad (Alosa sa idis-sima):

--+-

evidence for popu ations specific life history strategies in fish. J. Fish. Res. Board Can.

35(11):1469-1478.

Leggett, W.C.,

and R.N. O'Boyle. 1976.

Osmotic stress and mortality in adult 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 of the shad (Alosa sapidissima (Wilson)) with special reference to 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 consumption bv vouna Connecticut River shad A-loss sapidissima. J. Fish. Res.

Board Can. 29:1495-1499.

MacDonald, J.R. and R.A. Hyatt. 1973.

Supersaturation of air in water after passage through hydro-electric turbines at Mactaquac

Dam, Saint John

River, New Brunswick. J. Fish. Res. Board Can. 30:1392-1394.

Mansueti, R.J., and J.D. Hardy, Jr.

1967. Development of fishes of the Chesapeake Bay region. Part I. University of

Maryland, College Park, MD, 202 pp.

Mansueti, R.J.,

and H. Kolb. 1953. A historical review of the shad fisheries of North America. Ches-apeake Biol. Lab.

Publ. 97, Solomons, MD. 293 pp.

Marcy, B.C., Jr. 1972.

Spawning of the American shad, Alosa sapidis,-

sima, in the lower Connecticut River. Chesapeake Sci. 13(2):116-119.

Marcy, B.C., Jr. 1976.

Early life history studies of American shad in the lower Connecticut River and the effects of the Connecticut Yankee Plant.

Pages 141-168 in Am. Fish. Sot. Monogr.

No. 1. -

Massman, W.H. 1952.

Characteristics of spawning areas of shad, Alosa sapidissima (Wilson), in some Virginia 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, and C.W.

Billingsley. 1975. Annual progress report Delaware River Basin 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.

The American

- shad (Alosa sapidis-sima) in the Delaware River Basin. 1982. Prepared for the Delaware Basin Fish and Wildlife Management Cooperative, Rosemont, NJ. 132 pp.

Miller, J.P., W.M.

Zarback, J.W.

Friedersdorff, and R.W, Marshall. 1971.

Annual progress report Delaware River Basin Anadromous Fish Project, AFS-2-4.

U.S. Fish Wildl. Serv. 66 pp.

Miller, R.W. 1982.

An overview of the status of American shad (Alosa sapidissima) in Delaware.

Del.

Div. Fish Wildl. 13 pp.

Moffitt, C.M. 1979.

Recolonization of American shad, Alosa sapidis-17

sima (Wilson),

above Rainbow Dam fish-ladder, Farmington

River, Connecticut.

Ph.D. Thesis, Uni-versity of Massachusetts, Am-herst. 128 pp.

Moss, S.A. 1970.

The responses of young American shad to rapid temperature changes. Trans. Am.

Fish. Sot. 99(2):381-384.

Mu1 finger, R.M., and M.L. Kaufmann.

1980.

Fish passage at the Fairmount fishway in 1979 and 1980 with implications for the Schuylkill River fisheries through fishway construction.

Presented to The Academy o f Natural Sciences of Philadelphia, Schuylkill River Symposi urn.

September 24 and 25, 1980.

National Marine Fisheries Service.

1960-1977.

Statistical Digest, Fishery Statistics of the United States.

1J.S.

Dep.

Commerce.

Washington, DC.

Neves, R.J.,

and L. Depres. 1979. The oceanic migration of American

shad, Alosa sapidissima, along the 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 American shad in North Carolina.

Pages 17-31 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 index models:

American shad. U.S. Fish Wildl. Serv.

In press.

Sykes, J.E., and B.A. Lehman. 1957.

Past and present Delaware River shad fishery and considerations for its future. U.S. Fish Wildl.

Serv. Res. Rep. No. 46. 25 pp.

Talbot, G.B. 1954.

Factors associated with fluctuations in abundance of Hudson River shad.

U.S. Fish Wildl. Serv. Fish. Bull. 56:373-413.

Talbot, G.B., and J.E. Sykes. 1958.

Atlantic coastal migrations of American shad.

U.S. Fish Wildl.

Serv. Fish. Bull. 58(142):473-490.

Walburg, C.H. 1957.

Observations on the food and growth of juvenile American shad,.Alosa sapidissima.

Trans. Am.

Fish.

sot. 86:

302-306.

Walburg, C.H. 1960.

Abundance and life history of the shad, St.

Johns River, Florida. 1J.S. Fish Wildl. Serv. Fish. Bull. 60(177):

487-501.

Walburg, C.H.,

and P.R. Nichols. 1967.

Biology and management of the American shad and status of the fisheries, Atlantic coast of the IJnited States, 1960. U.S. Fish Wildl.

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 1985 ments of Coastal Fishes and Invertebrates (Mid-Atlantic)--

a Bmpriran shad

r. Author(~)

a Pe+anninc OrSanization Rept. h cc

1. PWlOrminS OrSanlraWn Name and Address

10. ~mi9CI/Tash/Worh Unit No.

Maine Cooperative Fishery Research Unit University of Maine U.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 coven National Coastal Ecosystems Team U.S. Army Corps of Engineers Fish and Wildlife Service Waterways Experiment Station U.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-82-4 IL Abatnti Kimit: 200 words)

Species profiles are literature summaries on the taxonomy, morphology, distribution, life history, and environmental requirements of coastal aquatic species.

They are designed to assist in environmental impact assessment.

The depleted populations of the American shad, Alosa sapidissima, are being restored in many of the rivers along the east coast that originally supported large runs.

The American shad is an anadromous fish that lives several years in the ocean and returns to its natal river to spawn in the spring when temperatures reach 12 "C.

The eggs are carried by ctirrents downstream from spawning sites in large rivers for 8-12 days until they hatch.

The larvae, which metamorphose to juveniles 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 they prefer salinities exceeding 4 ppt.

Estuaries S h a d Growth Feeding

b. IdW.tlRen/Ow,-Ended T.rmr American shad Salinity requirements Alosa sapidissima Temperature requirements Habitat 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=