The California sea lion crisis has deepened as the number of abandoned, sickly pups continues to increase and the Pacific Ocean becomes warmer.
To date, nearly 1,800 sea lions found stranded on California beaches have been admitted to rehabilitation centers statewide, according to researchers from the
Currently, 750 California sea lions are being cared for at the centers. The mammals are mostly 9 months old, dehydrated and underweight for their age.
"What's scary is that we don't know when this will end," said Shawn Johnson, director of veterinary science at the Marine Mammal Center in Sausalito. "This could be the new normal—a changed environment that we're dealing with now."
Researchers believe unusually weaker winds from the north and strong winds from the south have maintained ocean temperatures off the California coast and Alaska two to six degrees warmer than average. Warm ocean temperatures have resulted in a change in the current and a lack of upwelling, which helps bring colder water and fish to the surface.
As a result of the changes, conditions will be less productive off the coasts of California, Oregon and Washington, meaning fewer food sources for salmon and other marine species.
The high mortality of sea lion pups could be an early sign of that change.
The tropical El Niño, which NOAA declared in early March, could stretch conditions through 2015.
Toby Garfield, a research director at the Southwest Fisheries Science Center, said Tuesday that the environmental changes are "unprecedented."
In February, NOAA researchers visited the Channel Islands -- where most of America's sea lions breed -- and found the pups' average growth rate was alarmingly low.
But marine mammal organizations began noticing an increase in the number of stranded sea lions in December.
NOAA researchers will continue to track the species' response to the changing conditions.