By Jennifer Fisher with NOAA Fisheries:

If you’ve walked the beaches in Newport Oregon lately, you have probably noticed the high tide line littered with the small red bodies of what look like tiny lobsters. These are Pelagic Red Crabs (Pleuroncodes planipes), also known as squat lobsters, or tuna crabs, since they are a prey item for these fish. These organisms are a long ways from home.

These small squat lobsters normally live off Baja Mexico. During warming events, especially stronger El Niño events, these little squat lobsters can be found off Southern California to Central California, but they rarely venture much farther north than that. Pearcy and Schoener (1987) reviewed the occurrence of Pelagic Red Crabs off California and noted that they have occurred during or following major El Niño events from 1941, 1958-1960, 1969-1970, 1972-1973, 1979-1980 and 1983-84. However, none were observed during the 1997-98 El Niño (W. Peterson, personal observation).

Pelagic Red Crabs are not strong swimmers, so they are carried from place to place with the ocean currents. During our most recent trip aboard the NOAA ship Bell Shimada, we heard reports of Pelagic Red Crabs observed off Brookings Oregon, close to where we were sampling at the time. We never saw any at sea, but then they washed up on the local beaches a few days later. To the best of our knowledge, this is the first time that Pelagic Red Crabs have been observed on beaches off Oregon. How these crabs became distributed much farther north than previously reported is a mystery at this time. A closer look at the coastal currents might reveal the answers.