TitleDelayed upwelling alters nearshore coastal ocean ecosystems in the northern California current
Publication TypeJournal Article
Year of Publication2007
AuthorsBarth, JA, Menge, B, Lubchenco, J, Chan, F, Bane, JM, Kirincich, AR, McManus, MA, Nielsen, KJ, Pierce, SD, Washburn, L
JournalProceedings of the National Academy of Sciences of the United States of America
Volume104
Pagination3719-3724
Type of ArticleJournal Article
ISSN0027-8424
Abstract

Wind-driven coastal ocean upwelling supplies nutrients to the euphotic zone near the coast. Nutrients fuel the growth of phytoplankton, the base of a very productive coastal marine ecosystem [Pauly D, Christensen V (1995) Nature 374:255-257]. Because nutrient supply and phytoplankton biomass in shelf waters are highly sensitive to variation in upwelling-driven circulation, shifts in the timing and strength of upwelling may alter basic nutrient and carbon fluxes through marine food webs. We show how a 1-month delay in the 2005 spring transition to upwelling-favorable wind stress in the northern California Current Large Marine Ecosystem resulted in numerous anomalies: warm water, low nutrient levels, low primary productivity, and an unprecedented low recruitment of rocky intertidal organisms. The delay was associated with 20- to 40-day wind oscillations accompanying a southward shift of the jet stream. Early in the upwelling season (May-July) off Oregon, the cumulative upwelling-favorable wind stress was the lowest in 20 years, nearshore surface waters averaged 2 degrees C warmer than normal, surf-zone chlorophyll-a and nutrients were 50% and 30% less than normal, respectively, and densities of recruits of mussels and barnacles were reduced by 83% and 66%, respectively. Delayed early-season upwelling and stronger late-season upwelling are consistent with predictions of the influence of global warming on coastal upwelling regions.

URL<Go to ISI>://WOS:000244972400012
DOI10.1073/pnas.0700462104