Chemical and physical factors associated with yellow perch abundance in Great Lakes coastal wetlands: patterns within and among wetland types

Great Lakes coastal wetlands provide important spawning and nursery habitat as well as abundant food resources for yellow perch (Perca flavescens). We examined multiple years of fyke-net data from wetlands along Lakes Huron and Michigan to describe yellow perch distribution in drowned river mouth (DRM) and coastal fringing systems. Principal components analysis and multi-response permutation procedures indicated that DRM wetlands (yellow perch CPUE = 0.2) were eutrophic systems that often exhibit high temperatures and periods of hypoxia, whereas coastal fringing wetlands (yellow perch CPUE = 32.1) were less productive. Among the coastal fringing systems, Saginaw Bay (Lake Huron), displayed characteristics of being more productive and had more yellow perch. Most yellow perch captured in Saginaw Bay were age-0, suggesting that it was an important nursery habitat. Among DRM ecosystems, we found that the downstream lake macrohabitats contained more yellow perch than upstream wetlands; however, there was no significant difference in abiotic characteristics to explain the higher catches in lakes. We hypothesize that yellow perch were more prevalent in wetlands with intermediate productivity during summer because these systems provide abundant food resources without the harsh conditions associated with highly eutrophic wetlands.