Tiny ‘Tuna Crabs’ Swarm California Beaches Beyond ‘Normal’ Range
June 12, 2018 – These tiny, bright red crustaceans are called pelagic red crabs.They resemble crayfish, and are a type of squat lobster—not a true crab. Also known as tuna crabs, they are food to large fish, squid, and seabirds.
Pelagic red crabs are native to the warm waters of Baja California, Mexico. Only rare appearances were documented in Northern California, until recently. In 2015 and 2016, thousands were stranded on California beaches.
The migrations are linked to El Niño events, which carry warm currents northward. Scientists aren’t sure why the species has appeared in California every year since 2015. The warm-water crustaceans were documented for the first time in Oregon in 2017.