The proposed work consists of testing the hypothesis that recruitment pulses to rocky intertidal barnacle populations are caused by the collision of upwelling fronts with the rocky intertidal zone. It is hypothesized that the upwelling front is a place of convergence, and that larvae of intertidal barnacles accumulate there. To test this hypothesis, knowledge of the temporal history of the position and vertical structure of an upwelling front is required, along with knowledge of the distribution and abundance of larvae in the water column, and their recruitment success during periods of active upwelling and relaxation from upwelling. The PIs propose to address this issue through a series of field measurements consisting of: (1) use of shipboard net tows together with temperature, salinity, and velocity measurements along a transect off Monterey, California, on six short cruises during each of two upwelling seasons; (2) moored measurements of temperature and wind; (3) benthic monitoring in the intertidal zone; (4) shore-based measurements of temperature and salinity; and, (5) satellite AVHRR data.
