Gender Specific Spawning Migration in American Shad
American shad, Alosa sapidissima, were captured in set gill nets and in drift nets in the Cape Fear River system, North Carolina. The presence of three dams on the Cape Fear River was considered as a possible barrier to spawning migration. Anadromous fish were tagged with ultrasonic transmitters, and their migration habits were monitored by periodic relocation . One shortnose sturgeon and one american shad were relocated at lock and dam #1 and observed meandering in the vicinity of the dam for extended periods after making directed migrations upstream until reaching the barrier. Neither fish ever successfully crossed the dam. Shad locking began March 23, 1992 and ended May 1, 1992. This schedule could inhibit passage of shad present at dam#1 as early as mid February. Male shad were determined to initiate migration earlier in the season than female shad, and this difference in migration timing necessitates alteration of the existing shad locking schedule toward one which would more broadly encompass the spawning migration of the entire shad population.