Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (South Atlantic). American shad. [Alosa sapidissima]
The American shad (Alosa sapidissima) was the most valuable food fish on the Atlantic coast perior to the 1940's; but landings have declined drastically since that time, and sport fishing has become more important than commercial fishing in most rivers stocks still exist. The American shad is anadromous: adults congregate offshore in areas within the North Atlantic Bight during summer, move southward in coastal waters during fall and early winter, and move up rivers to spawn during late winter and spring. In rivers in the South Atlantic Region, the spawning run peaks during January and February, but can continue through April and May. Larval shad live in upriver areas and eat a variety of small invertebrates. Juveniles gradually move downriver and live estuaries, where they grow to about 100 mm in length and migrate to sea where they live 3-5 years before maturing. Most American shad return to their natal river to spawn; and in the South Altantic Bight, most adults die after spawning once. Development of eggs requires water temperatures of 14 to 20/sup 0/C, dissolved oxygen concentrations of at least 5 mg/l, and current velocities capable of buoying eggs during incubation. Downstream transport of the young and spawning migrations of adults can be adversely affected by excessive alteration of the river flow.
- Research Organization:
- Georgia Univ., Athens (USA). Georgia Cooperative Fishery Research Unit; Fish and Wildlife Service, Slidell, LA (USA). National Wetlands Research Center
- OSTI ID:
- 5327907
- Report Number(s):
- TR-EL-82-4/82-11.45; ON: TI86901599
- Country of Publication:
- United States
- Language:
- English
Similar Records
Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (North Atlantic): American shad. [Alosa sapidissima]
Immediate mortality of adult American shad (Alosa sapidissima) resulting from passage through a Kaplan turbine at Holyoke Dam, Massachusetts