Spatiotemporal Trends and Relationships in the Abundance, Growth, and Condition of Common Nearshore Fishes of Southwest Lake Michigan By

The Laurentian Great Lakes are large dynamic aquatic ecosystems with a diversity of available habitats and associated fish communities. The increasing prevalence of invasive species has influenced habitat associations of native species and altered trophic relationships throughout the food webs. We sought to identify habitat and biotic relationships associated with common nearshore fish abundance at three locations within the Illinois waters of southwest Lake Michigan. We utilized small-mesh gillnets to assess the fish community from June to October, 2008-2012. For yellow perch (Perca flavescens), age-0 and age-1 abundance varied annually, with water depth and water temperature, whereas age-0 yellow perch also showed a negative relationship with round goby abundance. Round goby (Neogobius melanostomus), abundance differed across locations, likely due to varying benthic substrate. Alewife (Alosa pseudoharengus) abundance showed significant variation across locations, being most abundant at the most northerly site. Relationships between the relative abundance of nearshore fish species can likely be attributed to behavioral interactions and differences in habitat preferences. Understanding the diversity of fish communities in nearshore areas could have implications for management of sport fish populations and influence the decisions on protection of critical habitats.