Age-0 yellow perch (Perca flavescens) were collected during October 1998 an
d age-1 yellow perch were collected during June 1999 from southeastern Lake
Michigan off St. Joseph and Muskegon, Michigan, to evaluate diets relative
to recent ecosystem changes. Size range of yellow perch examined was 72 to
118 mm. In October at a 15-m site off Muskegon, both Gammarus spp. and Iso
poda were found in nearly 71% of age-0 yellow perch stomachs,and accounted
for 71 and 26% of the diet by weight respectively. The following spring at
the 15-m site (June 1999). Gammarus spp. and Isopoda were only a small part
of age-1 yellow perch diet, and Chironomidae and Mysis relicta dominated t
he diet. In October at depths of 25 to 35 m, M. relicta, was found in 100 a
nd 80% of the age-0 yellow perch containing food off Muskegon and St. Josep
h, respectively, and comprised over 96% of the diet by weight. Gammarus spp
. Isopoda, and M. relicta were eaten in higher numbers than would be expect
ed based on their low abundance in the environment. The high occurrence of
Gammarus spp. and Isopoda in yellow perch diet may indicate ongoing changes
in the nearshore benthic community.