Mysterious Die-Off: Starving Sea Lion Pups Wash Ashore In Huge Numbers

Starving sea lion pups are washing up in huge numbers, and scientists don't know why. Some believe that the sea lions have hit their natural population limit in the wild, others blame changing oceanic temperatures. In any case, shelters are being overrun as rescuers work to save the adorable abandoned pups.

According to SF Gate, rescuers from all over California's southern coastline netted 250 starving pups, mostly 7-month-old babies that should be nursing with their mothers. Many more are washing up on the shorelines dead.

The year 2013 was a record "mortality event," according to the National Marine Fisheries Service, when about 1,500 sea lions washed up on the shore, most in the first four months of the year. The year 2015 is already shaping up to be an even greater shock to the sea lion's population.

David Bard, operations director at the San Pedro rescue center, told the Daily Mail, "[O]ur numbers are twice what they were in 2013. In 2013, we saw an unprecedented number of rescues, it was a record then."

Shawn Johnson of the Marine Mammal Center explained more.

"This is the third year that we've seen these mass die-offs, but this is the worst so far. If this continues, there will be some long-term effects on the sea lion population."

Luckily the sea lion population is in good shape. In 1972, the government passed the Marine Mammal Protection Act after decades of hunting the marine mammals for their hides and blubber. Now, the population has hit 300,000 and they are in no risk of extinction, according to the International Union for Conservation of Nature.

Still, the starving pups might be indicative of something much larger going on in the ocean.

One idea is that unusually warm waters around the California coast are forcing sea lion mothers to go further to hunt. These hunting trips might leave the pups away from their mother's milk for far too long, and most of the babies are too young to fish for themselves.

Another theory is that at 300,000, the population has simply hit its limit, and there's not enough food to provide for more growth.

The die-offs could also be caused by a yet unknown problem deep in the Pacific ocean. That's the theory that most concerns humans, as Justin Viezbicke explained.

"These animals are a puzzle piece for us. They provide insight into what's going on in the environment. … These things could come back and affect humans."

Whatever the explanation, rescuers and shelters of every kind are working to save the starving pups, force feeding the weakest and giving them antibiotics. Even Sea World in San Diego has taken in about 50 of the baby sea lions.

[Image Credit: refractor/Wikimedia Commons]