California Coast Faces Six-Month Marine Heat Wave As El Nino Returns

According to Lianhe Zaobao citing AFP, California’s coastal waters have been hit by a marine heat wave that has lasted about six months, with sea surface temperatures now 3 to 4 degrees Celsius above normal, according to data from the U.S. National Oceanic and Atmospheric Administration (NOAA). The warming has pushed anchovies and sardines, which whales and dolphins feed on, into deeper water or farther north into cooler areas, reducing the number of whales and dolphins seen by local sightseeing boats. NOAA oceanographer Reichen said California sea lions will soon be severely affected as the heat wave coincides with the return of El Nino, adding that higher temperatures can force mother sea lions to travel farther for food and spur harmful algal blooms that contaminate anchovies and sardines, causing sea lions to fall ill or die after eating them. Great white sharks, which prefer warmer water, are also moving closer to shore, a sight that has been relatively uncommon in the past. University of California, Santa Cruz adjunct professor Hasen said recurring marine heat waves could upset the balance of the ecosystem and eventually wipe out some fish species that serve as food sources.