Tuesday, August 02, 2005

The Day after ... Today?

Scientists puzzle over oddities along Pacific coast
SAN FRANCISCO, California (AP) -- Marine biologists are seeing mysterious and disturbing things along the Pacific Coast this year: higher water temperatures, plummeting catches of fish, lots of dead birds on the beaches, and perhaps most worrisome, very little plankton -- the tiny organisms that are a vital link in the ocean food chain.

Is this just one freak year? Or is this global warming?

Normally, in the spring and summer, winds blow south along the Pacific Coast and push warmer surface waters away from shore. That allows colder, nutrient-rich water to well up from the bottom of the sea and feed microscopic plants called phytoplankton.

Phytoplankton are then eaten by zooplankton, tiny marine animals that include shrimp-like crustaceans called krill. Zooplankton, in turn, are eaten by seabirds and by fish and marine mammals ranging from sardines to whales.

But this year, the winds have been unusually weak, failing to generate much upwelling and reducing the amount of phytoplankton.

Off Oregon, for example, the waters near the shore are 5 to 7 degrees warmer than normal and have yielded about one-fourth the usual amount of phytoplankton, said Bill Peterson, an oceanographer with the National Oceanic and Atmospheric Administration in Newport, Oregon.

"The bottom has fallen out of the coastal food chain, and there's just not enough food out there," said Julia Parrish, a seabird ecologist at the University of Washington in Seattle.

Seabirds are clearly distressed. On the Farallon Islands west of San Francisco, researchers this spring noted a steep decrease in nesting cormorants and a 90 percent drop in Cassin's auklets -- the worst in more than 35 years of monitoring.

On Washington state's Tatoosh Island, common murres -- a species so sensitive to disruptions that scientists consider it a harbinger of ecological change -- started breeding nearly a month late. It was the longest delay in 15 years of monitoring.

Researchers have also reported a sharp increase in dead birds washing up in California, Oregon and Washington.

Along Monterey Bay in Central California, there are four times the usual number of dead seabirds, said Hannah Nevins, a scientist at Moss Landing Marine Laboratories.

"Basically, they're not finding enough food, and they use up the energy that's stored in their muscles, liver and body fat," Nevins said.

Fish appear to be feeling the effects, too. NOAA found a 20 percent to 30 percent drop in juvenile salmon off the coasts of Oregon, Washington and British Columbia in June and July, compared with the average over the previous six years.

And researchers counted the lowest number of juvenile rockfish in more than 20 years of monitoring in Central and Northern California. Fewer than 100 were caught between San Luis Obispo and Fort Bragg this year, compared with several thousand last year.

Scientists have seen some of these strange happenings before during El Nino years, when higher water surface temperatures in the equatorial Pacific alter weather patterns worldwide. But the West Coast has not had El Nino conditions this year.

 

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