Characterizing lentic fish assemblages and community-environment relationships: An evaluation of natural lakes and reservoirs in Iowa, USA

Characterizing fish assemblages in lentic ecosystems is difficult due to high habitat heterogeneity and the diversity of methods available to sample fish. Therefore, multiple sampling methods are almost always necessary for gaining reliable estimates of species richness and for sampling different sizes of a particular species. However, most research on the use of multiple sampling methods has targeted recreationally-important species. As such, little information is available regarding the influence of multiple methods and timing (i.e., temporal variation) on characterization of lentic fish assemblages. We sampled six lakes and impoundments seasonally (i.e., spring, summer, fall) with beach seines, benthic trawls, boat electrofishing (i.e., day and night), modified fyke nets, mini-fyke nets, and gill nets (fall only) to evaluate the combined influence of sampling methods and timing on the number of species and individuals sampled. Probabilities of detection for species indicated strong selectivities and seasonal trends. Additionally, patterns in seasonal probabilities of detection and species 1 Iowa State University, Department of Natural Resource Ecology and Management, 339 Science II, Ames, IA 50010, USA. 2 U.S. Geological Survey, Idaho Cooperative Fish and Wildlife Research Unit, Department of Fish and Wildlife Sciences, University of Idaho, Moscow, Idaho 83844, USA.