2010 El Nino affecting North Pacific Ocean ecosystems adversely

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Washington, March 4 (ANI): Scientists at NOAA and Scripps Institution of Oceanography, UC San Diego, US, have revealed that the ongoing El Nino of 2010 is affecting north Pacific Ocean ecosystems in ways that could affect the West Coast fishing industry.

Researchers with the California Cooperative Oceanic Fisheries Investigations (CalCOFI) at Scripps and NOAA's Southwest Fisheries Science Center report a stronger than normal northward movement of warm water up the Southern California coast, a high sea-level event in January and low abundances of plankton and pelagic fish - all conditions consistent with El Nino.

Sea surface temperatures along the entire West Coast are 0.5 to 1 degree Celsius (0.9 to 1.8 degrees Fahrenheit) warmer than normal and at points off Southern California are as much as 1.6 degrees Celsius (2.9 degrees Fahrenheit) higher than normal.

The most unusually high temperatures were mapped around Catalina and San Clemente islands.

While strong winter storms caused an increase in coastal sea levels, scientists are investigating whether the higher sea levels are primarily a result of El Nino, a cyclical phenomenon characterized by warming eastern equatorial Pacific Ocean waters.

"Based on our previous experience of El Nino in California, it is likely to reduce ocean production below normal, with possible effects extending to breeding failure of seabirds, and much lower catches in the market squid fishery," said Sam McClatchie, a fisheries oceanographer at NOAA's Southwest Fisheries.

The NOAA and CalCOFI scientists have observed a drop in biological abundance, or productivity, that appears to be related to the northward movement of warm water from the equator.

The flow arrives in pulsing Kelvin waves that are detected by sea level and altimeter monitors and coastal tidal gauges.

The layer of warm water often stifles the upwelling of nutrients from lower ocean depths that sustain larger populations of fishes and invertebrates.

The researchers reported finding fewer hake and anchovy eggs than usual in the most recent CalCOFI surveys.

Sanddab and flounder eggs dominated the samples. Most were collected in a small area east of the Channel Islands.

The scientists added that if El Nino conditions continue, they are likely to be characterized by weaker than normal upwelling and lower biological production.

El Nino conditions are forecast to persist into spring. If so, greater biological anomalies than have already been observed, may develop. (ANI)

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