Thousands of red crabs, also known as tuna crab or pelagic red crabs, have invaded the shores of San Diego and Orange County.
The scarlet-colored crustaceans, which have been infesting the California coastline for quite a few weeks now, were believed to have been carried by warm water currents. Linsey Sala, of the Pelagic Invertebrates Collection at Scripps Institution of Oceanography, UC San Diego believe the phenomenon is caused by “warm water intrusions.”
— CNN (@CNN) June 17, 2015
Other experts believed that the tuna crabs’ invasion, which started almost a month ago, was caused by the warm-water occurrence which originated in the equatorial eastern Pacific, called El Niño.
Some scientists attribute the stranding to another warm-water phenomena called “warm blob.”
The Pleuroncodes Planipes, commonly known as red crabs, are quite unique because of their life cycle. These crustaceans mainly live their lives on the surface of the seafloor from “larvae to adulthood.”
The larger adult crabs have been known to occupy the “epibenthos” or just atop of the seafloor, and move in vertical directions to reach the surface and feed on phytoplankton.
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And because the red crabs inhabit the water column, they are easily affected by the winds, tides, and currents.
Pete Thomas of GrindTV noted that these were actually a type of squat lobster, and one of the plentiful species of micronekton, or “actively swimming organisms, which are larger than plankton”, which inhabit the California Current. The red crabs usually dwell between Chile, South America, and the coast of Baja, California.
Fishermen took the opportunity to use the crustaceans as bait for tuna, marlin, sharks, yellowtail and whales while underwater photographers took a dip to take eye-popping photos of the bright red crabs.
However, local residents are not as excited by the invasion of the shoreline. The crabs die almost instantly once they wash ashore, leaving behind a foul smell on the beach.
Experts also warned the locals to avoid consuming the red crabs as they may carry unknown toxins.
California Cooperative Oceanic Fisheries Investigations program has noted similar events in the past wherein other sea dwellers, aside from the red crabs, have washed onto the coasts of Southern California.
Katharine Gammon of LA Weekly listed the other sea animals which have invaded the SoCal coastline in the past. The list includes squid, Poralia jellyfish, kelp flies, Velella velella (a hydrozoan, which is a long-distance relative of the Portuguese man-of-war), and dead sardines.
[Image via YouTube]