Friday July 7, 2023
Bloomberg —
Sea lions and dolphins have been washing up sick or dead on Southern California beaches, poisoned by eating fish containing a dangerous neurotoxin. It’s the result of a harmful algae bloom, a natural phenomenon that turns water blue, bright green, brown or red, and occurs mostly in the summer and fall.
Algae blooms have been supercharged in recent years by agricultural pollution and global warming (the algae prefer warmer water). The returning climate pattern known as El Niño raises the likelihood of toxic algae outbreaks on the US West Coast and may do the same in Florida, though its influence there is not as clear cut.
Toxic algae can cause nausea, vomiting and skin irritation in humans, and can kill dogs and marine animals exposed to it. Severe blooms can force fishermen to shut down their operations due to risks to food safety. The National Oceanic and Atmospheric Administration (NOAA) estimates that nationwide, such events cause about $82 million in losses for the US seafood, restaurant, and tourism industries.
El Niño is set to cause more weather turmoil, test power grids and disrupt the global supply chain. Experts say its effects on algae outbreaks will vary considerably from place to place and species by species. It “depends on where and which harmful algae blooms,” says Richard Stumpf, an oceanographer at NOAA, which provides toxic algae forecasts across the US. “There are different harmful algae species, and they thrive in different environments.”