Threatening marine life, oxygen-poor ocean zones grow
Oxygen-starved waters are expanding in the Pacific and Atlantic as ocean temperatures increase with global warming, threatening fisheries and other marine life, according to a study published today. Times staff writer Kenneth R. Weiss reports:
Most of these zones remain hundreds of feet below the surface, but they are beginning to spill onto the relatively shallow continental shelf off the coast of California and are nearing the surface off Peru, driving away fish from commercially important fishing grounds, researchers have found.
The low-oxygen, or hypoxic, zones may also be connected to the Pacific Coast invasion of the Humboldt, or jumbo, squid. These voracious predators, which can grow 6 feet long, appear to be taking advantage of their tolerance for oxygen-poor waters to escape predators and devour local fish, another team of scientists theorizes.
Francisco Chavez, a study co-author and senior scientist at the Monterey Bay Aquarium Research Institute in Moss Landing, said that California can look to Peru for potential problems ahead. Peruvian authorities have struggled for a decade over a commercial fish called hake that is being squeezed between overfishing and oxygen-starved waters.
Humboldt squid apparently have been eating hake off California, just as they do off Peru, Field said. Some scientists believe the squid have expanded their range due to over-exploiting of sharks and other predators.
Humboldt squid can weigh 100 pounds. That's one being hoisted by fisherman Steve Consulo.
-- Francisco Vara-Orta
Photo: Erhardt Krause/Sacramento Bee