9402690 Gaines Although it is widely acknowledged that oceanographic processes influence benthic communities, little effort has focused on this issue in a synthetic way. Prior research by the PI's had taken a predictive and experimental approach to explaining spatial and temporal variation in the recruitment of the northern acorn barnacle, Semibalanus balanoides, in Narragansett Bay. About 80% of the large interannual variation in barnacle recruitment in the bay over the last decade is explained by annual variation in bay flushing times, which set the extent of retention and export of larvae from the bay. This renewal project will test the generality and consequences of the previous findings in other estuaries and examine additional taxa. Only by undertaking studies across biogeographic areas and a wide range of taxa will the linkages between oceanographic processes and the population and community dynamics of benthic assemblages be unraveled. The project will use replicated bays in New England with differing flushing characteristics to examine the relationship between spatial and temporal variation in bay flushing time and the recruitment of common shoreline species. The generality of mechanisms generating recruitment variation is an unresolved issue, yet it has important implications to the dynamics of marine communities. With simultaneous studies on five important space occupiers of the NW Atlantic, this project will begin to develop a general understanding of linkages between hydrodynamic processes and the populations and community dynamics of benthic assemblages. ***
