Saturday, March 13, 2010

El Niño Reducing Ocean Productivity

This winters El Niño has warmed sea surface temperatures throughout much of the North Eastern Pacific. Researchers with NOAA and the Scripps Institute for oceanography recently reported that, as expected, warm water has led to reduced plankton biomass and consequently low abundance of pelagic fish.

During El Niño events, warm southern waters often encroach on coastal regions from California to BC, bringing with it predators and competitors from the subtropical oceans. The widespread appearance of Humbolt squid in Coastal BC, normally found in coastal waters off the coast of Southern California and Baja Mexico is evidence of this shift in ocean temperatures. Along our coastal region, productivity is typically driven by strong seasonal upwelling which may be dramatically reduced during El Niño. After a few years of excellent ocean conditions and excellent returns, managers must now prepare for the potentially catastrophic consequences of poor conditions.

With a changing climate ocean conditions have already become more variable and in the future, El Niño conditions are expected to occur with a greater frequency. This highlights the need for adaptive, cautious management and a concerted global effort to curb emissions which cause climate change. See an article on current ocean conditions in the Columbia Basin Bulletin:

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