American Shad

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NOAA Technical Memorandum NMFS-NE

Status of Fishery Resources off the Northeastern US: American shad

1998
Resource Evaluation and Assessment Division
Northeast Fisheries Science Center

Stephen H. Clark, Editor


American Shad

by J. Kocik

Tables:

Gulf of Maine-Middle Atlantic American Shad

Recreational catches and commercial landings

The American shad, Alosa sapidissima, is an anadromous species which occurs along the Atlantic coast from southern Labrador to northern Florida. It also has been introduced along the Pacific Coast. American shad undergo extensive seasonal migrations, moving into rivers for spawning beginning in January in southern rivers, and continuing until July in the northernmost portion of their range. After spawning, shad migrate north along the coast to Canada where they feed during the summer. A southward migration occurs later along the continental shelf where the fish overwinter prior to spring spawning migrations to their natal rivers.

American shad have a range of life history patterns depending on their river of origin. In southern rivers, shad return to spawn at age 4 and die after spawning. Fecundity ranges from 300,000 to 400,000 eggs. Progressing northward, increasing numbers of spawners survive, the mean age at first spawning increases to 5, and fecundity decreases to 125,000 to 250,000 eggs.

Almost every major river along the Atlantic seaboard historically supported a spawning population of American shad. They have been exploited for their flesh and roe since prior to Euro-American settlement. Atlantic coast landings exceeded 22,000 mt in 1896. In contrast, commercial landings north of Cape Hatteras, N.C. have averaged less than 1,100 mt annually since 1980. Since 1993, annual landings have exceeded 600 mt only once, in 1995. The principal gear used is the gillnet. Recreational angling is popular and catches may be significant, but no comprehensive estimates are available.

Excessive fishing has been blamed for historic declines in abundance in the Hudson and Connecticut Rivers, as well as in rivers in Maryland, North Carolina, and Florida. Throughout North America, dam construction along many larger rivers led to an almost complete disappearance of shad in many watersheds and the loss of associated fisheries. Pollution in the lower Delaware has been cited as the primary cause for the decline of the fishery in that system.

The Atlantic States Marine Fisheries Commission has implemented a coastwide management plan for American shad and river herring to facilitate cooperative management and restoration plans between states. Restoration efforts have involved habitat improvement, fish passage, stocking, and transfer programs. Despite improved returns in some major river systems such as the Susquehanna, Delaware and Connecticut Rivers, the range-wide abundance of American shad is well below historic levels.

A recent assessment characterized fishing mortality for 9 river stocks and resource trends for 13 river stocks of American shad. Total fishing mortality rates (river and coastal) were below the overfishing definition (F30%) for the 9 stocks that were evaluated. These results suggest that recent levels of exploitation in coastal intercept fisheries have not adversely impacted these stocks. In addition, juvenile shad production indices for 7 of these stocks suggested recruitment failure only in Maine. However, the total range of extant American shad populations includes additional populations in small river systems and small populations in larger river systems that are actively being restored. Also, much historical shad habitat is vacant and may be targeted for restoration in the future. For these stocks, individual states have developed fishing mortality targets to protect small stocks and rebuild others. Assessment studies have not quantitatively addressed these systems because of limited biological data. Like all mixed stock fisheries, small stocks can be at risk under conditions of uncertainty. Overall, this resource is considered to be fully exploited and at low levels of abundance.

 


For further information

Crecco. V.A. 1997. Stock assessment of American shad from selected Atlantic coast rivers. Atlantic States Marine Fisheries Commission, Washington, D.C. ASMFC Spec. Rpt.

Gibson, M.R., V.A. Crecco, and D.L. Stang. 1988. Stock assessment of American shad from selected Atlantic coast rivers. Atlantic States Marine Fisheries Commission, Washington, D.C. ASMFC Spec. Rpt. No. 15.

Richkus, W. A., and G. DiNardo. 1984. Current status and biological characteristics of the anadromous alosid stocks of eastern United States: American shad, hickory shad, alewife, and blueback herring. Martin Marietta Environmental Center, Columbia, MD.

 


Gulf of Maine-Middle Atlantic American Shad

 
Long-term potential catch= Varies by stock
SSB for long-term potential catch == Unknown
Importance of recreational fishery= Major  
Management= Interstate FMP for Shad and River Herring
Status of exploitation= Varies by stock
Age at 50% maturity  = 2 to 4 years (varies by latitude)
Size at 50% maturity= 40 cm (15.8 in.)
Assessment level= Index
Overfishing definition= F30%
Fishing mortality rate corresponding to overfishing definition= Varies by stock to overfishing definition

M = varies by latitude; F0.1 = Variable; Fmsy = Variable; F1996 = Variable


 

Shad Graph

Recreational catches and commercial landings (thousand metric tons)

Year
Category1977-86 Average1987198819891990199119921993199419951996
U.S. Recreational
-
-
-
-
-
-
-
-
-
-
-
Commercial           
United States
1.2
1.3
1.4
1.3
1.3
1.1
0.9
0.6
0.6
0.6
0.6
Canada
-
-
-
-
-
-
-
-
-
-
-
Other
-
-
-
-
-
-
-
-
-
-
-
Total Nominal Catch
1.2
1.3
1.4
1.3
1.3
1.1
0.9
0.6
0.6
0.6
0.6