California’s red crab swarm linked to Pacific ‘blob’

SAN DIEGO – Red crabs, by the thousands, have invaded Southern California beaches, washing ashore from San Diego to Newport Beach.

Sea surface temperatures some four to seven degrees warmer than normal, possibly connected to a radical change in a Pacific ocean weather pattern, are likely driving the crabs northward away from their typical habitat.

“Experts said the crabs haven’t been seen in the area for decades,” reported the Orange County Register.

The crabs, resembling miniature lobsters too small to eat, are known as tuna crabs or pelagic red crabs.

Donna Kalez, general manager of Dana Wharf Sportfishing, told the Orange County Register that boat captains spotted the creatures for weeks in the water.

Now that they’ve washed ashore, “everyone is taking selfies with the red crab,” Kalez told the paper.

“They are all still alive. They are in the surf line and swimming up. Once they get this close to shore, they can’t go anywhere, so they just wash in. They aren’t strong enough to swim out.”

Fisherman first spotted the little red crabs in Southern Californian waters last year and reports came in earlier this year of sporadic strandings on Catalina Island and elsewhere.

Starting in mid-May, thousands washed up on San Diego beaches.

“Typically such strandings of these species in large numbers are due to warm water intrusions,” said Linsey Sala of Scripps Institution of Oceanography, UC San Diego.

In addition to the crabs, the warm Pacific coastal waters have drawn northward a number of other creatures seldom or never previously seen, which last fall included – a live ocean sunfish and warm-water blue shark in the Gulf of Alaska, mahi mahi off the coast of Oregon, a Pacific sea turtle common in the Galapagos near San Francisco, and marlin in the waters off Southern California.

“In recent weeks, blue, jellyfish-like creatures known as ‘by-the-wind sailors’ have been spotted, and tropical fish like yellowtail and bluefin tuna are showing up earlier than normal this year,” the Orange County Register said.

The warm plume of water developed in the spring of 2014.

Nick Bond, a climatologist at the University of Washington, dubbed it “the blob” and published a study exploring its origins.

“The study finds that it relates to a persistent high-pressure ridge that caused a calmer ocean during the past two winters, so less heat was lost to cold air above,” explained a University of Washington news release.

“The warmer temperatures we see now aren’t due to more heating, but less winter cooling.”

The blob has been linked to the weather pattern that has led to drought in California, and much colder than normal conditions during winter in the eastern US the past two years.