Fish Communities in Multiple Floodplain Habitats of the Fourche Lafave River, AR, An Un-Leveed River-Floodplain System

Floodplain habitats provide important spawning and nursery habitats for fishes (e.g., oxbow lakes, seasonally inundated floodplain, and low-order tributaries).  Relative to oxbow lakes; low-order tributaries are an understudied feature of the river-floodplain.  Understanding tributary usage by fishes is important because oxbow lakes are no longer being naturally created in regulated systems.  Previous sampling in tributaries along the Fourche LaFave River, AR, using seine and mini-fyke nets has yielded 36 adult and 42 young-of year species. Species include ecologically important fishes (Dorosoma cepedianum and D. petenense), recreationally important fishes (Lepomis macrochirus and Micropterus salmoides), and species of conservation concern (Atractosteus spatula and Erimyzon succeta).  In May, June, and July 2012, mini-fyke nets were used to sample 4 upper tributaries, 4 lower tributaries, and 3 oxbow lakes, to describe and compare fish communities found within each habitat along the Fourche LaFave River. Preliminary analyses of July mini-fyke net data showed a significant difference in species richness between habitats (P=0.03), but no difference in total abundance (P=0.48). On average, both richness and total abundance was highest in lower tributaries followed by oxbow lakes and upper tributaries. Our research suggests an apparent undervaluing of tributaries relative to oxbow lakes and necessitates further investigation.