The Marine Mammal Care Center in San Pedro, Calif., has seen a surprisingly large number of malnourished, dehydrated sea lion pups coming into its shelter for care this year -- over 90 of them total.

"We have a lot of cases for a very short time," Dave Bard, director of the Marine Mammal Care Center in San Pedro, a community near the region's massive ports and harbor, told NBC Los Angeles.

Although it's common for the sea lions to fall ill at this time of year, the number of animals being brought in is especially high compared to the usual count, according to NBC.

The total number of animals admitted in 2013 so far is expected to be 100 or higher this week, Bard told NBC.

It's unclear why so many of the animals are getting sick, Bard told NBC, and so far there is no clear pattern.

Sea lions that get sick during the winter suffer from natural illnesses and injuries, wounds from fishing gear in the water, or interaction with ocean debris, Bard told NBC.

But any theories at this point, he emphasized to the station, would be speculative.

Although the center does blood tests on the animals when they arrive, no specific trends are emerging, Bard to NBC.

"They're here because they're not getting the nutrition that they need, of they've succumbed to some illness," he added to the station.