This project examines the hypothesis that recruitment pulses to rocky intertidal barnacle populations are caused by the collision of upwelling fronts with the rocky intertidal zone. A front separates the relatively cold and salty upwelled water nearshore from the relatively warm and fresh water further offshore. It is hypothesized that the upwelling front is a place of convergence, and that larvae of intertidal barnacles accumulate there. At certain times such fronts appear to collide with the shore and to deposit their accumulated larvae on the rocky intertidal zone, thereby producing a recruitment peak. To test this hypothesis, knowledge of the temporal history of the position and vertical structure of an upwelling front is required, contemporaneously with knowledge of the distribution and abundance of larvae in the water column and their recruitment success. This will be achieved through use of satellite AVHRR data, shipboard net tows and temperature, salinity, and velocity measurements, moored and shore-based measurements of temperature and wind, and benthic monitoring in the intertidal zone. This research is significant in increasing our understanding of recruitment and of cross-shelf transport, and in developing predictive models for the dynamics of coastal populations with pelagic larvae.
