MELISSA BLOCK, HOST:
Since the start of the year, nearly 2,000 sea lion pups have washed up on California's shores starving and emaciated. It's not uncommon for some sea lions to wash up each spring as the pups leave their mothers for the first time, but the numbers this year have been overwhelming. As NPR's Nathan Rott reports, animal rescue and rehabilitation centers are having a hard time keeping up.
NATHAN ROTT, BYLINE: There are more than two dozen pens at the Marine Mammal Care Center in San Pedro, Calif. holding more than a hundred animals grouped by health.
LAUREN PALMER: These guys on this half of the facility are actually doing pretty well. They're eating on their own, they're playing, they're porpoising.
ROTT: Lauren Palmer knows well - she's the chief biologist for the center and she looks tired.
PALMER: I haven't had a day off in a very long time.
ROTT: Try January 1. She walks across the wet concrete to a dog kennel a few feet away, where two of the center's newest arrivals are laying on each other. They don't even blink as Palmer kneels beside them.
PALMER: So these are two that are in fairly critical condition.
ROTT: Pretty lethargic and just...
PALMER: When he inhales, you can just see every rib. Hanging on by a thread.
ROTT: In their weakened conditions, Palmer says, some of the sea lion pups get sick. Many here have pneumonia.
PALMER: They're really - you can see this one's coughing.
ROTT: With antibiotics, water and food, some get better.
PALMER: Some of them we're just not going to be able to save.
DAVID BARD: We are having to make some decisions as to which animals have the best chance of survival and focusing on those.
ROTT: David Bard is the operations director for the center.
BARD: In March of this year to date, we've had over 330 California sea lions admitted so far, which is unprecedented. It's up by about four or five times what we usually see.
ROTT: Now, the surging numbers isn't a threat to sea lion populations overall. Their numbers are still robust. Still, wildlife biologists and scientists at the National Oceanic and Atmospheric Administration, or NOAA, are working to figure out just why exactly this is happening. The general consensus is that ocean waters are warmer than normal, in part because there's a lack of typical strong north winds. That's affecting ecosystems and food chains, including those around Southern California's Channel Islands, where many sea lions are born. Justin Viezbicke is a stranding scientist for NOAA.
JUSTIN VIEZBICKE: We believe that the warm waters are basically pushing the prey items for the California sea lion mothers further and deeper away from the islands.
ROTT: Which is causing the mothers to be gone longer than they normally would, leaving the pups alone, hungry and eventually desperate enough to set out on their own before they're physically ready.
VIEZBICKE: So when and if they do make it to the mainland, they're showing up in very poor condition.
ROTT: Scientists have seen events like this before, though smaller, most recently in 2013 but again in 2010 in 1998. The difference is, in those years, there were strong El Ninos that caused the warmer waters.
NATE MANTUA: We don't have that this year.
ROTT: That's Nate Mantua, a climate scientist with NOAA. He says this year and last are far more complicated. There are unusual climate patterns, like a persistent high-pressure ridge hanging over the West, which many climatologists are blaming for the dry heat in the West and the record snow in the East. But Mantua says he doesn't think the unusual patterns are a new normal - it could just be an anomaly. But he adds...
MANTUA: We are in an era of really remarkable sort of rapid change and stuff that's really important for the climate system.
ROTT: Back at the Marine Mammal Care Center, it's feeding time. In one pen, healthier sea lions are trying to swallow fish whole. In another, workers and volunteers are gently holding pups down, tube-feeding them a puree of raw fish, electrolytes, vitamins and protein. Laura Palmer says she hopes this isn't the new normal.
PALMER: If this is the new normal then we have a real problem on our hands, a bigger problem. An ecosystem problem, not just one individual starving animal.
ROTT: And the resources are already spread pretty thin with just the one. Nathan Rott, NPR News, Los Angeles.
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