Wildlife experts sounded the alarm Tuesday over a surge in famished sea lions, including many pups, stranded on Californian beaches.
Nearly 2,000 of the beached sea mammals have been registered since the start of the year, said the National Oceanic and Atmospheric Administration (NOAA).
"We are seeing an unusually large increase of California sea lion pups stranding on the beaches of southern and central California," the authority said on its website.
In January and February, strandings were 20 times the average rate for the time of year.
In a conference call with reporters, an NOAA official said that up to March 15 more than 1,800 sea lions had been recorded, 750 of which were brought into its facilities, to be fed back up, treated for any health problems and then released into the ocean.
The Pacific Marine Mammal Center (PMMC), which looks after between 200-300 of the mammals each year, also said it had registered an increase in adult sea lions requiring rescue and medical treatment.
Experts say warming sea temperatures are at least in part responsible, changing the availability of fish and other organisms on which sea lions prey.
Female sea lions, which weigh some 100 kilos (against some 400 kg for males), have to swim further to find food, leading them to become prematurely separated from their pups.
The next two months are likely to see an even greater surge in strandings, along the lines of a 2013 Unusual Mortality Event (UME), experts say, before hopefully the numbers will start to fall.
Nate Mantua of NOAA said one piece of good news was signs of northerly winds which would help bring colder waters more rich in nutrients, at least in northern California.
This could ease the food crisis which is driving the strandings, he said.