Movements of Adult American Shad (Alosa sapidissima) in the Holyoke Dam Tailrace During their Spawning Migration: Final Report to Northeast Utilities
adult, American shad, shad, Alosa sapidissima, Holyoke, Holyoke Dam, tailrace, spawning, migration, Northeast Utilities, pool, Connecticut River, spillway, fish elevator, elevator, Hadley Falls, hydroelectric, entrance, Holyoke Canal, canal, turbines, delay time
Massachusetts Cooperative Fishery Research Unit, Department of Forestry and Wildlife
None supplied. Introduction: In order for adult American shad to reach the Holyoke Pool spawning grounds in the upper Connecticut River, they must first be lifted over Holyoke Dam. Spillway and tailrace fish elevators have been constructed at Holyoke Dam for this purpose. The spillway lift is located at the base of the dam alongside the powerhouse for the Hadley Falls Station Unit No. 1 Hydroelectric Station. The tailrace elevator entrance is located alongside Hadley Falls Station. For this reason, fish seeking passage upriver have access to only one elevator at a time, depending on their course of travel, the tailrace or mainstream river route. The fish elevators at Holyoke Dam have lifted approximately 380,000 American shad over the dam in each of the last two years (Krska and Kynard, 1982). While the spillway fish elevator lifts approximately 88% of the American shad that are lifted over Holyoke Dam (Henry, 1976), this elevator is commonly shut-down several weeks prior to the end of the spawning migration. Due to the reduced flow and level of the river in late spring, flashboards are installed along the crest of the Holyoke Dam. The installation of boards raises the 'head' held behind the dam by approximately three feet and eliminates spillage over the dam. The lack of flow over the dam prevents adult shad, and other anadromous fishes present, from reaching the spillway fish elevator entrance. All river water is then redirected through the Holyoke Canal system and Hadley Falls Station Unit #1. The tailrace is then the only remaining route open for fish seeking passage upriver. A second generating turbine will be installed at Holyoke Dam during 1981 and 1982. The additional water released into the tailrace with both turbines operating could pose problems for shad ascending the tailrace, on their way to the fishlift. For this reason, the objectives of the present study, funded by Northeast Utilities Service Company were to: (1) determine the ability of American shad to negotiate flows in the tailrace with Unit No. 1 operating, (2) determine the delay time of shad in the tailrace prior to lifting, (3) describe the general movement patterns of shad immediately below Holyoke Dam and in the tailrace area during 1980 and 1981.