Spatial and Temporal Patterns in the Macrobenthos of St. Louis Bay, Mississippi

Benthic community structure in St. Louis Bay was studied for 23 months. Cluster analyses distinguished two habitats: open water areas and areas near the marshy shores of rivers and bayous. Two groups of “euryhaline opportunistic” species were dominant at the open water stations. Temporal patterns of the “euryhaline opportunists,” which appeared to be controlled by a combination of reproductive pulses and seasonally intense predation, showed that the greatest abundance of macroinfauna occurred during the cooler months with reduced recruitment during the second year. The river-bayou stations were characterized by two groups of “estuarine endemic” species. One of these groups was most abundant in the warmer months and the other in the cooler months. Changes in abundance of the “estuarine endemics” appeared to reflect seasonal cycles