Ebert As part of a study of the possible influence of large-scale current patterns on the recruitment of sea urchins, we have been monitoring the weekly settlement of sea urchins at sites in northern and southern California since 1990. Past El Nino events appear to have significantly affected the settlement of several species. In northern California, an unusually high sea urchin settlement in 1992 and 1993 was associated with the breakdown in upwelling and changes in surface currents, as indicated by satellite imagery. In southern California, however, there was evidence of decreased settlement. Currently a new El Nino event is occurring in the southern hemisphere. We propose a collaborative study that will expand the spatial scale of our observations to include central California and to increase the taxonomic scope of our investigations by including brachyuran crabs and bivalves. This investigation will provide a unique opportunity to test predictions based on our earlier work in different oceanographic regions.
