Red Tide: Tiny Crabs Blanket California Beaches

Thousands of tuna crabs were washed up on the shores of Balboa Island in southern California on June 16.

Hundreds of thousands of tiny crabs have been washing up on Southern California beaches, marring the sandy coastline with streaks of red, as warm ocean currents carry them farther north and closer to shore than usual, officials said on Wednesday.

The red tuna crabs have been dying in hordes on beaches from San Diego to Orange County, although some have been washed back out to sea alive. Such strandings take place periodically and are not necessarily a threat to the species, according to Linsey Sala, collection manager for the Pelagic Invertebrates Collection at the University of California, San Diego's Scripps Institution of Oceanography, "This is definitely a warm-water indicator," Sala said. "Whether it's directly related to El Nino or other oceanographic conditions is not certain."

The plankton-eating crabs, native to the waters of the Gulf of California, Baja California and the California Current, are one to three inches (2.5-7.6 cm) long and resemble tiny lobsters.

San Diego's Scripps Institution of Oceanography has cautioned people not to eat the crabs because the creatures may have ingested toxin-producing phytoplankton. Debbie Heenan