Seasonal occurrence, distribution, and power plant entrainment of larval fishes in Presque Isle Harbor, Lake Superior.

Larval fishes were found in the harbor during all months except September-November. Larvae of most taxa appeared only beween April and August, but coregonines and fourhorn sculpin Myoxocephalus quadricornis occurred from December to July and December to June, respectively. In 1976, coregonines and fourhorn sculpin reached peak abundance about mid-May, followed by rainbow smelt Osmerus mordax in late May, lake trout Salvelinus namaycush and white sucker Catostomus commersoni in early June, yellow perch Perca flavescens in mid-June, burbot Lota lota in late June, sculpins of the genus Cottus in mid-July, and ninespine stickleback Pungitius pungitius in late July. Total entrainment from August 1975 through 1976 was estimated at 8.8 X 10⁶ larvae (<30 mm SL). Rainbow smelt, coregonines, fourhorn sculpin and lake trout accounted for 92.8%, 3.4%, 1.5% and 1.2% of this estimate, respectively. Entrainment appeared to be associated with seasonal succession of larvae, behavioral characteristics of larvae, and physical factors such as river discharge, harbor circulation, and wave action.-from Sport Fishery Abstracts