Studies of the American Shad, Alosa sapidissima (Wilson) in the Lower Susquehanna River below Conowingo Dam (Maryland), 1972-1976
Proceedings of a Workshop on American Shad
In 1970, an agreement was signed between various utilities, states, and the federal government for the implementation of a five year program 'for restoration of the American shad to the Susquehanna River.' Part of the program called for construction of a fish attraction, collection, and trapping facility to determine the number of American shad (Alosa sapidissima) available from immediately below Conowingo Dam that could be collected and transported upriver and released. A collection facility was operated daily from April through June between 1972 and 1974. Some 5.8 million specimens of 48 species was taken. In order of abundance, the most common fishes were the white perch (Morone americana), blueback herring (Alosa aestivalis), gizzard shad (Dorosoma cepedianum), channel catfish (Ictalurus punctatus), and American eel (Anguilla rostrata). Combined, these species made up 90.3% of the catch. The American shad ranked 28th in catch per effort. A total of 673 shad was taken in five years in 1,828 hours of operation. The largest number (293) was taken in 1972. Most were taken in the last week of May and the first two weeks in June. Typically, when collected, one to three shad were taken per lift. Certain trends are apparent after five years of study. Few shad have been captured. No evidence exists to suggest that the low catch is due to inefficient operation of the collection facility. Evidence from several sources (angler catch in the tailrace and the commercial fishery at the mouth of the river) suggests that a decline has occurred in the shad population over the last 20 years. The effect of this decline on efforts to restore runs of the American shad remains to be resolved.