The Northern California Current Ecosystem: climate variability and indices of ocean conditions for fishery management

Bill Peterson¹ and Edmundo Casillas²

¹ NOAA Fisheries, Northwest Fisheries Science Center, Hatfield Marine Science Center, Newport, Oregon

² NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Blvd E., Seattle WA

We use ecosystem information derived from more than 10 years of physical and biological ocean observations to produce environmental indicators that provide ecosystem-based forecasts of salmon returns. Our suite of indicators are based on large scale climate indicators as well as local in situ measurements of both physical and biological oceanographic conditions in the upwelling zone off Oregon and Washington. These indicators include the Pacific Decadal Oscillation, the Multivariate Index of El Niño activity, date of the physical spring transition, strength of upwelling, temperature and salinity of upwelled waters, copepod biodiversity, biomass anomalies of cold water and warm water copepods, date of biological spring transition, and catches of coho and Chinook during pelagic trawl surveys. The strength of our approach is that our biological indicators are directly linked to the success of salmon during their first year at sea through food chain processes. When our biological indices are coupled with physical oceanographic data, the combined set of indices offers new insights into the mechanisms which lead to the success or failure of salmon runs. The indices are available on the web: http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/a-ecinhome.cfm. Include in this website is a table that lists our forecasts of salmon returns, using a red-yellow-green light approach. Much of what we provide in this report addresses the long-standing question, “What are the biological linkages and mechanisms that explain the correlation between physical forcing (e.g., upwelling) and ecosystem response? “.