Designation could bring more aid

of volunteers, who have to cover more hours and tend to more pups. The stays can last for months as they build up their health so they can be returned to the sea.

Bard said rescuers have been forced to prioritize so that the facilities have room for the most critically ill animals.

They have cared for pups with injuries and abscesses, some that had seizures and some that had gotten tangled in fishing lines.

Bard said he hopes the federal designation will provide more funds for the center, allowing it to bring in more help.

Since 1991, federal wildlife officials have declared 57 unusual mortality events, including, most recently, for bottlenose dolphins in Texas in 2011 and 2012 and for North Alaska and Northeast pinnipeds in 2011.

The designation will also mobilize researchers — including biologists and oceanographers — to try to find an answer that has evaded others thus far.

Sharon Melin, a wildlife biologist with the National Marine Fisheries Service, said it’s not uncommon for sea lion pups to become stranded, but the recent occurrences have been troubling because of the scale, the time of year and the mystery surrounding their cause.

As more pups leave their mothers, Melin added, the problem isn’t likely to subside until summer.

“Usually, we know the problem,” she said. “We knew what was coming. When we saw the effect, we knew what it was caused by.”

Typically, that would be

‘They’re not old enough and big enough to be out on their own. They’re really naive and trying to make their way.’

— Sharon Melin, a wildlife biologist with the National Marine Fisheries Service, about the rescued sea lion pups

disease or warmer ocean temperatures, such as during an El Niño.

“What’s different about this incident,” she said, “is we don’t have any of that.”

The only anomaly, Melin said, is that these pups should still be with their mothers. The animals that have been found stranded were born over the summer and are about 6 to 8 months old.

The pups might have been left behind by mothers who had to venture farther out to sea to forage for food, forcing the young ones to leave the rookeries earlier and fend for themselves.

“They’re just not capable at this age,” Melin said. “They can’t dive deep, they’re not very efficient swimmers. They’re not old enough and big enough to be out on their own. They’re really naive and trying to make their way.”