El Niño Brings Tropical Marine Species to California's Coast
Warm-water species have appeared off California's coast this autumn, and the first documented sea turtle nests on the US West Coast have been found. Scientists link the changes to this year's unusually strong El Niño.
Marine animals normally found in much warmer regions have been showing up off the coast of California, in the United States, in recent months. Scientists attribute this to this year's especially strong El Niño, a climate phenomenon in which warm Pacific Ocean waters spread farther north and carry tropical species with them. The shift matters for local fishing and for the marine ecosystem, as it also has negative effects.
Unusual sightings
This autumn, whale sharks, hammerhead sharks, flying fish and manta rays have been observed off California. In September, an angler near Los Angeles caught a longspine bigeye, a fish never before recorded in California waters.
In Orange County, a venomous yellow-bellied sea snake washed ashore in September. A beachgoer used a palm leaf to help the seemingly weakened animal return to the water. Los Angeles Natural History Museum specialist William Ludt said only six or seven confirmed sightings of the snake have been made in California; it was previously seen in 2015–2016, when El Niño was also under way.
The most surprising discovery involves sea turtles. In September, olive ridley sea turtle nests were found on two California beaches: the first was spotted on 16 September in Seal Beach, and the second three days later in nearby Huntington Beach. It is the first documented case of sea turtles laying eggs on the US West Coast. To protect the eggs from waves and storms, scientists moved them to the Aquarium of the Pacific in Long Beach, where specialists are monitoring them.
Winners and losers
Local fishers have welcomed the change. Donna Kalez, co-owner of Dana Wharf Sportfishing & Whale Watching, said fishers have caught about 5,000 yellowfin tuna this year, compared with just two last year.
Scientists warn, however, that warmer water threatens kelp forests, which provide habitat for many marine species. The strong El Niño, together with Pacific hurricanes, has also raised water levels and worsened coastal erosion; in places, huge waves have damaged homes and washed away beaches. A state of emergency has been declared in California in preparation for possible further storms.
Experts forecast that once El Niño subsides, ocean conditions should largely return to normal next year. Until then, scientists say other rarely seen or previously unrecorded species could appear in California waters.
