Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 8362
Title: The state of the California Current, spring 2008-2009: cold conditions drive regional differences
Author: Sam McClatchie, Ralf Goericke, Franklin B. Schwing, Steven J. Bograd, William T. Peterson, Robert L. Emmett, Richard Charter, William Watson, Lo Nancy, Kevin Hill, Collins Curtis, Mati Kahru, B. Greg Mitchell, J. Anthony Koslow, J. Gomez-Valdes, Bertha E. Lavaniegos, G. Gaxiola-Castro, Jon Gottschalk, Michelle L'Heureux, Yan Xue, Marlenne Manzano-Sarabia, E. P. Bjorkstedt, Stephen Ralston, J. Field, Laura Rogers-Bennett, Lisa Munger, Greg Campbell, Karlina Merkens, Dominique Camacho, Andrea Havron, Annie Douglas, John Hildebrand
Publication Year: 2009
Journal: California Cooperative Oceanic Fisheries Investigations Reports
Volume: 50
Pages: 43-68
Keywords: California Current, CCS, primary production, ocean ecosystem, upwelling,
Abstract:

This report describes the state of the California Current system (CCS) between the springs of 2008 and 2009 based on observations taken along the west coast of North America.  The dominant forcing on the CCS during this period were La Niña–type conditions that prevailed from summer 2007 through early 2009, transitioning to neutral El Niño–Southern Oscillation conditions in spring 2009.  The Pacific Decadal Oscillation index was negative during this period, and its values had not returned to normal by spring 2009.  General effects on the California Current system were stronger–than–normal southward winds and upwelling, as well as generally colder–than–normal SST and shallow nitraclines; however, there were regional differences. 

Off Baja California, sea surface temperatures did not respond to La Niña conditions; however, concentrations of chlorophyll a (Chl a) were significantly above normal, probably due to the anomalously high upwelling off Baja during most of the year.  Off southern California there was no clear evidence of increased primary or secondary production, despite observations that previous La Niña conditions had affected mixed–layer depth, temperatures, nutrients, and nitracline depths. 

In both central and northern California and Oregon, stronger–than–normal upwelling increased primary production and prevented potential spawning of sardine north of San Francisco.  In central California, the midwater fish community resembled that of recent cool years, and cover by kelp was much reduced along the coast.  Off Oregon there was evidence of increased abundance of boreal copepods, although the neritic boreal species did not appear to extend as far south as central California.  Current predictions are for cooler conditions to change to El Niño conditions by the end of 2009; these are expected to last through the Northern Hemisphere winter of 2009&ndash2010. 

URL1: The next link will exit from NWFSC web site http://www.calcofi.org/publications/calcofireports/v50/Calcofi_vol.50_finals.pdf
Theme: Habitats to Support Sustainable Fisheries and Recovered Populations
Foci: Characterize relationships between habitat and ecosystem processes, climate variation, and the viability of organisms.