Climate change effects on planktonic ecosystems: a five decade perspective from CalCOFI

Summary form only given. Interannual scale perturbations, especially El Nino, have long been known to influence vertical stratification, nutrient supply, geographic distributions of organisms, and food web structure in the California Current. Here we address longer term, multi-decadal scale influences on California Current planktonic food webs. We focus on both the species composition of zooplankton assemblages and on the stable N isotopes of selected species. Sampling was conducted by CalCOFI (the California Cooperative Oceanic Fisheries Investigations), the longest biological oceanographic time series in North America and among the most comprehensive ocean time series in the world. This research is a component of the U.S. GLOBEC Northeast Pacific program.