Sporadic Events

Pelagic Red Crabs Enter Monterey Bay (2015-17, 1982-83, 1969, & 1959)

Thousands of pelagic red crabs (Pleuroncodes planipes) cover Coral Street Beach in Pacific Grove, CA on October 7, 2015
Thousands of pelagic red crabs (Pleuroncodes planipes) cover Coral Street Beach in Pacific Grove, CA on October 7, 2015


  • In 1859 pelagic red crabs were first discovered after a large stranding in Monterey Bay.
  • Warm currents generated during ENSO events carried pelagic red crabs to Monterey Bay in 1959, 1969, 1982-1983, and 2015-2017.
  • Pelagic red crabs normally live off the coast of Baja California, Mexico.
  • Pelagic red crabs are an attractive food to species that include migratory fishes, tuna, giant squid, turtles, pinnipeds, seabirds, and whales.

Most recent sightings:

March 8, 2017 at Lover’s Point, Pacific Grove, CA

Monterey Herald Article (3/9/17)

Esther Vanderhorst tries to avoid stepping on pelagic red crabs that are still alive while crossing a large pile of them after kayaking with her husband, Phil, at Lovers Point Beach in Pacific Grove on Thursday.
Pelagic red crabs that have washed ashore at Lover’s Point in Pacific Grove on 3/8/17. Photo by David Royal – Monterey Herald



January  6, 2017 at Fisherman’s Shoreline Park, Monterey, CA

Pelagic red crabs washed ashore at Fisherman’s Shoreline Park (near the wharf) on January 6, 2017. (Photo: Chad King, NOAA/MBNMS)














The 2015-16 and 1982-83 El Niño Southern Oscillation (ENSO) events brought huge numbers of pelagic red crabs (Pleuroncodes planipes) northward to Monterey Bay (watch video). The presence of Pleuroncodes, which look like bright-red baby lobsters, is indicative of the intrusion of southern sub-tropical waters into central California, since these crustaceans normally live in the warm waters off the coast of Baja California. During an ENSO event, warmer southern water moves poleward, often bringing marine species not normally found in the cold temperate waters off the coast of California. Several warm temperate and sub-tropical species, including Pleuroncodes, are observed beyond their normal geographic range during ENSO events, and sometimes as far north as Oregon and Washington.

IMG_3474_CEK IMG_3468_CEK  IMG_3523_CEK

Red pelagic crabs (Pleuroncodes planipes) washed up on Coral Street Beach in Pacific Grove, CA. These crustaceans began washing ashore the day prior and were seen in even greater densities. This is an exceedingly unusual event for the Monterey area, as these crabs are normally offshore of Baja California, but warm waters have transported them north. These crabs haven't washed ashore in this area since 1983, an El Nino year. NOAA is tracking a current El Nino that has contributed to the warm water plume.

Pleuroncodes stranding events are rare occurrences in Monterey Bay and usually coincide with ENSO events. The species was first discovered in 1859 during a mass-stranding event in Monterey. Further stranding events in Monterey occurred later in 1959 and again in 1969. Dr. Steve Webster, senior marine biologist at the Monterey Bay Aquarium, noted that when present, seagulls were feeding on so many crabs that they could not get airborne. Pleuroncodes are also a source of food for fishes, rays, and pinnipeds (seals and sea lions).

More images of pelagic red crabs from the SIMoN Photo Library


Del Monte Beach May 23, 2016. Photo by Dr. Andrew DeVogelaere, NOAA MBNMS.
Pelagic red crabs on the Del Monte Beach and in the water on May 23, 2016. Photo by Dr. Andrew DeVogelaere, NOAA MBNMS.


Links to More Information

Red crabs appear in Oregon for first time!

Images and info from Bodega Marine Lab

Images of larvae from Bodega Marine Lab

December 2016 event

Images of the Pelagic Red Crab Online




El Niño Theme Page


Pelagic Red Crabs in San Diego


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