Past studies of El Nino have suggested a variety of impacts on marine ecosystems-increased disturbance from storms, reduced productivity from lowered nutrient concentrations, and elevated mortality from increased temperatures. Arguably the largest effect, however, is the redistribution of species along the coast. Range extensions were a common phenomenon in the 1982/83 El Nino, as southern species were found well north of their typical range. This study is designed to examine the connections, between altered circulation patterns during the present El Nino and the dispersal and subsequent settlement of pelagic larvae. Because the microscopic larvae of marine invertebrates are like millions of drifters released along the shore, the results of this study can also help us interpret the physical oceanographic changes associated with a large El Nino. Once we determine the patterns of larval invasion driven by the El Nino, we will be in a position to examine the consequences to the invaded communities. Future studies will follow the fate of transplanted individuals after the 1997/98 El Nino goes away. Together, these studies will greatly enhance our understanding of how marine ecosystems respond to this major climatic event.
