"Mass Death of Seabirds in Western U.S. Is 'Unprecedented'"

From National Geographic:

By Craig Welch

PUBLISHED JANUARY 23, 2015

In the storm debris littering a Washington State shoreline, Bonnie Wood saw something grisly: the mangled bodies of dozens of scraggly young seabirds.

Walking half a mile along the beach at Twin Harbors State Park on Wednesday, Wood spotted more than 130 carcasses of juvenile Cassin's auklets—the blue-footed, palm-size victims of what is becoming one of the largest mass die-offs of seabirds ever recorded.

"It was so distressing," recalled Wood, a volunteer who patrols Pacific Northwest beaches looking for dead or stranded birds. "They were just everywhere. Every ten yards we'd find another ten bodies of these sweet little things."

Cassin's auklets are tiny diving seabirds that look like puffballs. They feed on animal plankton and build their nests by burrowing in the dirt on offshore islands. Their total population, from the Baja Peninsula to Alaska's Aleutian Islands, is estimated at somewhere between 1 million and 3.5 million.

Last year, beginning about Halloween, thousands of juvenile auklets started washing ashore dead from California's Farallon Islands to Haida Gwaii (also known as the Queen Charlotte Islands) off central British Columbia. Since then the deaths haven't stopped. Researchers are wondering if the die-off might spread to other birds or even fish.

"This is just massive, massive, unprecedented," said Julia Parrish, a University of Washington seabird ecologist who oversees the Coastal Observation and Seabird Survey Team (COASST), a program that has tracked West Coast seabird deaths for almost 20 years. "We may be talking about 50,000 to 100,000 deaths. So far."

....On some beaches the Cassin's auklet death toll was a hundred times greater than any bird die-off ever tallied there....

Bill Sydeman, a senior scientist at California's Farallon Institute, said he believes the most likely scenario is that the deaths are related to a massive blob of warm water that heated the North Pacific last year and contributed to California's drought and to 2014 being the hottest year on record.

That water was hotter and stayed warm longer than at any time since record-keeping began. It stretched across the Gulf of Alaska, where a high-pressure system blocked storms, preventing the water from churning to the surface and mixing with air. More warm water eventually moved inward along the coast as far south as California, altering how favorable the environment was for the zooplankton that many fish and birds, including Cassin's auklets, feed on.

That all happened in late summer—about the same time the young auklets began to fledge.