Friday, June 24, 2011
The waters off California’s coast are a superhighway for the Pacific Ocean's top predators. A new study underscores the importance of protecting the vital ecosystem.
A group of scientists who spent a decade tracking 4,300 marine animals now have a detailed portrait of the Pacific Ocean’s hidden underworld.
Most of the 23 species studied in the Tagging Of Pacific Predators project migrate and congregate in the waters off California because of its abundance of food, according to the report published this week in the journal Nature by scientists around the world, including San Diego.
Scientists compared the California Current ecosystem to Africa’s Serengeti Plain for its richness of life. The current, which moves south along the West Coast from Canada to Mexico, is highly productive due to the cold water upwelling, which brings to the surface nutrient-rich sediments, supporting large populations of sea life.
“It doesn’t matter if they’re elephant seals, or blue whales or leatherback turtles, all of these animals are coming to the California Current as a foraging ground," said Scott Benson, marine ecologist with the U.S. National Marine Fisheries Service. "This provides further information of the importance of the California Current to these large, highly mobile marine predators."
Benson said one of the biggest surprises of the study was the 7,000-mile migration of leatherback turtles. He electronically tracked the species from nesting beaches in Indonesia all the way to California, where they feed on jellyfish. Then, he said, they turn around and head back.
“This was a significant breakthrough for us to find out the source for these animals and to learn of these extreme ranges and movements all the way across the Pacific Ocean," Benson said. "It’s a species that has been on the planet for 70 million years and the populations in the Pacific are in peril."
The marine ecologist said knowing where and when marine species travel and migrate is valuable information to protect critical species and ecosystems.
The study comes days after another group of global scientists warned the oceans are on the edge of mass extinction.
The International Program on the State of the Oceans reports "a combination of stressers" – including global warming and overfishing – are creating dead zones that threaten to wipe out entire marine ecosystems within a generation.