Seasonal Fish Community Comparison for Two Lakes in the Upper Barataria Estuary, Louisiana, Including Impacts of Hurricane Isaac

Construction of flood protection levees along the lower Mississippi River disconnected the southern-most western floodplain from the river, causing water levels to fluctuate due to local precipitation, thus resulting in a loss of a seasonal flood pulse in the upper Barataria Estuary, Louisiana.  This project compared the fish communities of Lac des Allemands and Lake Cataouatche for each season (Spring 2012, Summer 2012, Fall 2012, Winter 2013) over one year.  The shorelines of twelve random sites within each lake per season were electrofished for 600 s and all fish were identified and enumerated.  Depth (cm), floating and rooted vegetation (% cover), and the number of coarse woody debris, trees, and stumps were quantified at each electrofishing site.  A total of 3,227 fish within 37 species were collected, with 11 species unique to Lake Cataouatche (including several marine species) and 3 species unique to Lac des Allemands.  Based on principle components analyses, there was little difference between lakes for each season, but there was a community change across the seasons, explained mostly by lower numbers of centrarchids in fall and winter.  Fish abundance and vegetation decreased following fish kills associated with Hurricane Isaac, which made landfall 28 August 2012.