Landscape-scale influences on stream fish assemblages in eastern Oklahoma

Ecoregions are commonly used as a starting point for regional management planning and conservation applications. The objective of this study was to relate watershed characteristics to stream fish assemblages among aquatic ecoregions and stream types in eastern Oklahoma. We compiled fish collection data from three studies in eastern Oklahoma, and filled data gaps by seining streams that were not represented in these collections. Watershed and stream characteristics were compiled and summarized using a GIS. Differences in stream and watershed characteristics and fish assemblage parameters among ecoregions were analyzed with analysis of variance and least significant difference multiple comparison test. Multivariate techniques were used to identify stream groups and relationships between species assemblages and watershed characteristics.;To adequately capture fish assemblage patterns and issues, one must delineate management regions specific to streams, with a clear understanding of landscape patterns, stream channel conditions, habitat features.