Abstract
Variability in recruitment of organisms to oyster reefs is dependent, in part, on larval supply. Distribution and abundance of larvae of three dominant decapods found on oyster reefs in Estero Bay, Florida- Petrolisthes armatus, Eurypanopeus depressus and Rhithropanopeus harrisii - were quantified using monthly plankton tows. Larval densities of the marine stenohaline P. armatus were greater in bay waters and near passes; the euryhaline E. depressus occurred abundantly throughout the bay and near tidal tributaries; and R. harrisii, which favors reduced salinities, were most abundant near tidal tributaries with high freshwater inflow. Densities of P. armatus and E. depressus peaked at the end of the dry season (May) and were depressed with the onset of seasonal rains (June). Larvae of R. harrisii were in short supply during dry months but abundant during the wet season. Weighted saljnity of capture was higher for P. armatus (30.9) and E. depressus (30.2) than for R. harrisii (9.2), and larval density was positively correlated with salinity and freshwater inflow for P. armatus and E. depressus and negatively correlated for R. harrisii. The distribution of juveniles and adults, collected using lift nets from oyster reefs at the mouths of tidal tributaries, largely reflected larval supply: P. armatus was absent from reefs experiencing low salinities; R. harrisii was found only in association with reefs experiencing low salinities; and E. depressus was found on all reefs. These results suggest the importance of considering the effects of salinity and freshwater inflow on spatial and seasonal variation in larval supply in understanding recruitment dynamics of oyster- reef associates.