Bear Swamp Pumped Storage Hydroelectric Project Fishery Study: Progress Report No. 4
hydroelectric, pumped storage, stratification, white suckers, sucker, yellow perch, perch, reservoirs, creel census, fish population, Deerfield River, trout
Massachusetts Division of Fisheries and Wildlife
1975 was the first full year of commercial operation of the Bear Swamp project. It was used most heavily in July and August when an average of nearly 3000 acre-feet of water was pumped daily. No stratification developed in either reservoir. Fish sampling in July produced 84 fish in the lower reservoir, primarily white suckers and yellow perch, but an equal sampling effort in the upper reservoir produced only 6 fish. The reservoirs buffered swings in temperature of incoming water. Minimum flows released from the lower reservoir occasionally appeared to drop substantially below the 100 cfs level for April to October as determined from USGS gage records. Creel census and water sampling results were essentially similar to previous years. The number and diversity of benthic animals sampled three miles below the Bear Swamp project continued to increase markedly. Hints at an improvement in conditions for natural fish populations are provided by the occurrence of slimy sculpins in Deerfield River samples for the first time in this study and an increased number of unmarked trout collected in fish samples near Charlemont.