New Delhi: A powerful El Niño event could significantly alter marine life along California’s coast, with unusually warm Pacific waters expected to push tropical and subtropical species farther north, marine biologists say.
The warming, described as a “Super El Niño,” could make Southern California’s waters more tropical and potentially bring new risks for marine life and coastal communities.
Douglas McCauley, director of the Benioff Ocean Initiative at the University of California, Santa Barbara, said warm-water anomalies were already pushing tropical and subtropical species into California waters where they are rarely seen.
One potential visitor is the yellow-bellied sea snake, a highly venomous species normally found in tropical waters of the Pacific and Indian oceans. Sightings of the snake in Southern California are extremely rare. A snake found in Newport Beach in 2018 was only the fifth documented sighting in the region since 1972, according to reports. Three of the four earlier sightings occurred during the powerful 2015-16 El Niño.
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Early arrival of sharks
The effects of warmer waters could also be felt among species that already inhabit California’s coastline.
Juvenile great white sharks, for instance, do not typically travel this far north early in the year. They generally remain near Baja California and move toward California as adults in autumn, a period known locally among surfers as “Sharktober.”
Marine biologists now expect rising sea-surface temperatures to draw juvenile great whites north earlier in the year, potentially bringing them into areas such as Morro Bay, Monterey Bay and possibly San Francisco Bay.
The movement of sharks could also follow their prey. Fish species are themselves shifting their ranges as ocean temperatures rise, potentially drawing juvenile sharks into new areas in search of food.
Early, unusually large catches of dorado and yellowfin tuna — both warm-water species — are cited as indications that such a shift may already be underway.
The region has also witnessed changes in shark activity during previous El Niño events. Hammerhead sharks were spotted off the California coast during the powerful 2015 El Niño, and two shark bites that year were specifically attributed to hammerheads, according to the report.
The developments highlight how large-scale changes in ocean temperatures can affect the distribution of marine species, potentially bringing animals into waters closer to the coast where they are rarely encountered.
(Edited by Ratan Priya)