## A-2. Eastern Boundary Currents

U.S. GLOBEC has published a science plan for research in the California Current Ecosystem (U.S. GLOBEC Report No. 11, 1994). The goal of a Califonia Current System (CCS) study is, "To understand the effects of climate change on the distribution, abundance and production of marine animal populations in the CCS". The approach is to study the effects of past and present climate variability as a proxy to better understand how the CCS may respond to future global warming and climate change. Dominant temporal scales of variability in the CCS are interannual, primarily due to the El Niño-Southern Oscillation linking atmospheric and ocean dynamics, and decadal, manifest primarily as large scale shifts in the structure (or productivity) of the system, due to large scale shifts in the position of atmospheric cells and associated physical forcing. In spatial terms, the dominant scales of variability in the CCS are: first, latitudinal, with large gradients in physical forcing and species composition from north to south; and second, mesoscale, with prominent squirts, jets, and filaments, especially off central and northern California. U.S. GLOBEC's research in the CCS will focus on these temporal and spatial scales of variability. Accordingly, we will investigate the linkage between growth, reproduction, mortality, genetic composition, physiological condition, transport, and recruitment of holoplankton, meroplankton, and icthyoplankton and the dominant spatial and temporal variability of physical forcing. U.S. GLOBEC will attempt to understand how populations adapt to the different mesoscale dynamics that occur latitudinally in order to provide a better indication of the consequences of climate change to the ecosystem. Finally, we aim to better understand the abrupt shifts that occur infrequently so that perhaps we may recognize future shifts early and provide useful advice to managers of harvestable living marine resources in the California Current. Table 4 contains a summary of the scientific objectives and the approaches that will be used to meet these objectives. A tentative schedule of activities in the CCS appears in Table 2. More information can be obtained from U.S. GLOBEC Reports No. 7 and No. 11.

U.S. GLOBEC hopes to collaborate with other programs investigating the California Current Ecosystem, or other EBCs. Numerous field efforts already obtain large volumes of multidisciplinary data from the CCS. These are mostly sponsored by NOAA, NSF, ONR, and MMS; in addition, regular long term sampling programs are conducted by CalCOFI, NMFS, state agencies, and numerous regional academic and research institutions. The Coastal Ocean Processes (CoOP) program intends a multidisciplinary study of the U.S. west coast, as a representative example of a strongly wind-driven shelf system. CoOP and U.S. GLOBEC have been discussing how to best collaborate to achieve more than either program could achieve independently. Studies of other EBCs will either be ongoing or are planned for the period when U.S. GLOBEC will be studying the California Current ecosystem. Connections to the active programs off South America, the west coast of Africa, South Africa (Benguela Ecology Program-BEP), and the Iberian peninsula would be welcome and probably best coordinated through GLOBEC International. This offers an opportunity to undertake regional comparison to examine EBCs having different levels of physical forcing. International linkages will also occur through GLOBEC International's Small Pelagic Fish and Climate Change (SPACC) initiative. Mexico and Canada conduct frequent and regular physical and biological surveys off their west coasts. Collaboration would greatly facilitate the regional latitudinal comparison of biological response to mesoscale physical forcing and the study of transition zones along the west coast.