Photo via Michael R Perry via Flickr CC
Sea lions are having a hard time finding food this spring, and pups are feeling the squeeze. Marine mammal experts report that dozens of sick and hungry sea lion pups have washed up on California shores this winter, many not making it even with the help they get at rescue centers. The Pacific Marine Mammal Center in Laguna Beach alone has treated 27 pups found since December. Only 11 have survived. And researchers are blaming a lack of food. PhysOrg reports that the warming of the ocean due to El Nino has reduced the amount of the sea lions' usual prey of squid and fish. This same rush of starving sea lions happened in 1998, also an El Nino year. However, Guy Oliver from University of California, Santa Cruz goes into more detail, stating that the lack of fish comes from "nn uncoupling of what is called curl upwelling and coastal upwelling -- wind-driven water currents that bring nutrient-rich water to the top" which pushes fish farther offshore, out of the sea lions' usual range.
Mercury News reported last month that many yearlings at Año Nuevo Island Reserve had been abandoned by their mothers even though they were too still too young to find food for themselves. Simultaneously, the mortality rate of sea lion pups on San Miguel Island off Santa Barbara shot up from the typical 30% to nearly 80 percent in 2009. Mothers were unable to feed enough to keep themselves alive, let alone nurse their young.
"This is unlike any other year with California sea lions," Oliver said. Without enough food, the yearlings couldn't build up enough blubber, which meant they couldn't keep warm enough to go fend for themselves in the frigid waters.