A sea lion is shown on the Columbia River near Bonneville Dam Monday, March 8, 2010, in North Bonneville, Wash. Wildlife officials have tried everything to keep sea lions from eating endangered salmon, dropping bombs that explode under water and firing rubber bullets and bean bags from shotguns and boats. Now they are resorting to issuing death sentences to the most chronic offenders. (AP Photo/Rick Bowmer)

(AP) -- Marine mammal experts say dozens of hungry and sick sea lion pups have washed up on Southern California beaches this winter and many have died at rescue centers.

Veterinarian Richard Evans said Thursday that the Pacific Marine Mammal Center in Laguna Beach has treated 27 skinny pups since December, but only 11 have survived.

Evans says nine of the 12 pups now at his center are in critical condition, "just skin and bones."

Rescuers say the ocean warming makes the sea lions' prey, squid and fish, scarce.

Evans says the last influx of starving sea lions came in 1998, which was also an El Nino year. The same has been blamed for sickening hundreds of California brown pelicans.