Riparian and instream variation among headwater streams of the Bogue Chitto River, Louisiana USA

The headwater streams of the Bogue Chitto River in southeastern Louisiana have historically supported many fishes currently ranked as species of concern by the Louisiana Department of Wildlife and Fisheries.  In 2007 and 2008, we sampled 8 sites within 3 headwater tributaries of the Bogue Chitto River to provide current occurrence records for 11 fish species of concern.  We used electrofishing to estimate fish species richness and abundance and collected water quality and habitat data.  The only species of concern encountered was the flagfin shiner Pteronotropis signipinnis, with 3 individuals collected at 2 of 8 sites.  We ran several statistical tests at two spatial scales (site and tributary) to relate variation in fish community structure to variation in site habitat characteristics and water quality.  Although we found significant differences in habitat at both spatial scales, none of the measured variables were related to site or tributary fish abundance or richness.  Principal component analyses revealed the presence of several definable assemblages, which appeared to be related to canopy density, riparian vegetation, substrate size and woody debris abundance.  We hope to revisit these headwater sites to track changes in habitat and fish community composition to assist management decisions within this region.