El Niño Gives California Crabs

El Niño Gives California Crabs

This year’s monster El Niño is truly a monster — it’s been blamed for killing coral reefs. Add another die-off to the list: Southern California beaches are blanketed in hundreds of thousands of tiny crabs. So many that it’s turning the beaches red.

Lead image by Scripps Institution of Oceanography

Pleuroncodes planipes, or tuna crabs (although they’re not true crabs, they’re actually lobsters), are normally found in waters off the coast of Mexico’s Baja California, to the south. But as we know already, nothing about this year is normal, and the warmer waters of El Niño have swept the critters further north. The crabs likely swarmed as they were trying to mate and were pushed ashore by strong currents. “Typically such strandings of these species in large numbers are due to warm water intrusions,” according to Linsey Sala, from the Pelagic Invertebrates Collection at Scripps Institution of Oceanography at UC San Diego.

The crabs are most intense on the Southern California shores of Orange County where beaches are covered in so many crustaceans that the beaches actually appear orange (ok, maybe a dark coral) from the air.

Dead and dying #redcrabs at #piratescove in #coronadelmar

A photo posted by Christine Lister (@psychprof) on

This isn’t the OC’s first run-in with crabs. The same type of “red tide” also happened in 2015, and also thanks to warming ocean temperatures. Local homeowners complained about the smell, but many cities refused to remove them because doing so would disturb grunion eggs laid in the sand. Birds managed to take care of the all-you-can-eat seafood buffet on their own, so Crabfest 2016 will probably be a lot like Crabfest 2015.

El Niño has also messed with our crabs once before, thanks to an algae bloom in The Blob, the El Niño-enabled warm waters off the coast of the Pacific Northwest. In that case, the algae was secreting domoic acid, a potentially lethal neurotoxin that was making its way into locally harvested seafood. Right now, a different El Niño algae bloom — an actual red tide — is poisoning fish in Chile.

The tuna crabs found on the California coast probably aren’t filled with those neurotoxins, but scientists don’t recommend that you eat them. Still, they’re still adorable lil’ guys, aren’t they?