Yellow perch were studied as a portion of a total environmental baseline study in 1972 before operation of a new pumped storage power plant on the eastern shore of Lake Michigan near Ludington. Of 1,546 perch taken by gill nets, age III (1969 year class) and IV fish contributed 40.1% and 27.4% of the total number, with male fish being taken much more frequently than females in all age classes during spring sampling. Comparative growth and length-weight data indicated that the perch were generally growing to larger sizes than those reported previously from the Great Lakes. Most fish older than age I were sexually mature and spawned in shallow littoral waters from mid-May to late June. Mature fish spent the summer in the littoral zone and moved to deeper water by late fall. The ratio of ovary weight to body weight was 20-25% before spawning, declined sharply, and increased again in fall. Ninety-six female fish examined for fecundity had a range of 10,654 to 157,594 eggs, and in general, because of the larger sizes of the fish, had greater fecundity than previously reported for other yellow perch. Regression equations were developed for fecundity vs. length (logarithmic), weight (linear), ovarian weight (logarithmic), and age (semi-logarithmic).
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