Attraction of Adult American Shad to Fish Lifts at Holyoke Dam, Connecticut River
adult, attraction, collection facility, Connecticut River, delay time, fish lifts, Holyoke, Holyoke Dam, microstructures, radio tags, shad, spillway, tailrace, turbines, turbulence, upstream, upstream migration
Journal or Book Title
North American Journal of Fisheries Management
The movements of 18 radio-tagged American shad were studied in 1980 and 1981 as they attempted to locate the upstream fish collection facilities of two fish lifts at Holyoke Dam on the Connecticut River in Massachusetts. Nine fish (50%) were passed by the lifts during the two years, and in 1980, the efficiency of the tailrace lift was estimated at 42%. The mean delay time of the seven fish passed by the tailrace lift during the two years was 3.3 d; the delay of the two fish passed by the spillway lift in 1981 was 6 and 7 d. Fish were repelled by the turbulence caused by the turbine discharge into the head of the tailrace and only entered the vicinity of the tailrace lift during 55% of all upstream trips in 1980 and 67% of the trips in 1981. During high river flows, fish were attracted to the spillage over the dam, not the flow from the tailrace. The inefficiency of either lift to pass early migrating American shad and of the tailrace lift to pass fish efficiently at any time may limit upstream passage during some years. The situation at Holyoke Dam, together with similar problems at other upstream dams, prevents many fish from reaching the historical upstream limit of their range and creates a poor or, at best, an unpredictable sport fishery upstream.