Spatial and Temporal Variation in the Distribution of Fishes of the LaBranche Wetlands Area of the Lake Pontchartrain Estuary, Louisiana

Abstract

The LaBranche Wetlands are located along the southwestern shore of Lake Pontchartrain. During early summer of 1989 and 1990, an electroflshing survey of 6 stations In Bayou LaBranche and Bayou Trepagnier, a tributary, yielded 10,644 specimens representing 38 species in 19 families. All fishes were typical of brackish to freshwater, low gradient systems of the Gulf Coastal Plain. Members of the Lepisosteidae, Clupeidae, Fundulidae, Poecillidae and Centrarchidae were numerical dominants. Results from rotenone samples at five of the same stations by Louisiana Department of Environmental Quality in 1986, and net samples at one common site by Thompson and Verret (1980) bring the total number of species for the LaBranche Wetlands to 52. Differences in the physicochemical characters of the two bayou systems were reflected in the dissimilar faunas between the two bayous. Results from detrended correspondence analysis (DCA) and community similarity indices indicate a high degree of variance at sites within the same bayou system over time.