OFFSHORE PELAGIC FISH COMMUNITY 8

Lantry et al discuss the offshore pelagic fish community which consists of fishes that occupy the warm upper and cool middle layers of water during June-October, when the lake is thermally stratified. Stewart et al called this zone the offshore pelagic habitat zone, and they included in it, for illustrative purposes, all waters where the bottom depth was greater than 15 m, except those in embayments. Offshore pelagic predators include Chinook salmon, coho salmon, rainbow trout, and brown trout (all non-native) and the reintroduced (native) Atlantic salmon. Although salmon and trout abundance is maintained mainly by stocking, some natural reproduction also occurs. The prey-fish community in the offshore pelagic zone is dominated by the alewife (non-native) and includes much smaller populations of four native planktivores--threespine stickleback, emerald shiner, spottail shiner, and cisco. Only remnant populations of the formerly abundant cisco persist in Lake Ontario.