Hundreds of sea lion pups have been found severely underweight and stranded on Southern California beaches this year, overwhelming marine mammal centers with starving animals.
To help relieve pressure on rescue centers to the south, Crescent City's North Coast Marine Mammal Center recently received seven emaciated 6- to 9-month-old sea lions from Southern California and will feed and care for the pups until they can be released into the wild.
"We're just trying to fatten them up for now," said Marlana Garcia, a center volunteer of more than four years, as she tossed fish into the pens of barking sea lions.
The fattening has been successful so far as each pup has put on 2andndash;6 pounds since arriving April 7, but the sea lions still have a lot of gaining to do as they are expected to reach 60andndash;70 pounds before they are released.
Stranded pups in Southern California have been coming in as light as 18 pounds when they should be close to 50 pounds or heavier, according to officials with National Oceanic and Atmospheric Administration.
"The majority of them are under a weight that's typically ever seen for this age," said Sarah Wilkin, NOAA's marine mammal stranding coordinator for California.
As of Wednesday, 1,293 stranded California sea lions had been found since the beginning of the year - five times the average from January through April in the past five years, NOAA officials said.
The high numbers prompted NOAA to declare an "unusual mortality event" last month, defined under the Marine Mammal Protection Act as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response."
The situation was so dire this year that rescuers sometimes exercised beach triage, retrieving only the most critical pups, leaving others to survive - or not - on their own.
This year's event was foreshadowed by underweight pups observed last September at the rookeries on the Channel Islands, where the vast majority of California sea lions are born.
Sharon Melin, a wildlife biologist with the National Marine Fisheries Service, said scientists coastwide are investigating the cause of the strandings, especially looking at disease and food shortage, using data that goes back to the 1940s. There haven't been any direct links yet, but the event appears to mirror the food shortage that happens in El Nino years.
"What's made this event very interesting is that the population is responding the way we see in El Nino events," Melin said. "In El Nino all the prey gets moved far away and the mother has a hard time bringing back enough nutrition for her pup."
The declaration of the "unusual mortality event" allowed more federal funds to be used to investigate the cause and conduct more tissue sampling of stranded sea lions, but conclusions could still be months away, Melin said.
"The event could be ending. We just don't know what it will look like in the next couple months," Melin said.
There did appear to be a decline in sea lion strandings, Wilkin said, but that could also be attributed to fewer people on beaches this past week with poor weather conditions in Southern California.
Three sea lions rescued during this year's crisis were deemed "unreleasable" after the animals were found re-stranded shortly after being released by rescue centers, Wilkin said. They will now have to go to a permanent care facility, like a zoo.
Other animals released, including two with satellite tags, were shown diving and foraging on their own "so at least two animals were successfully rehabilitated," Wilkin said.
Because of the time it takes to rehabilitate the pups, Crescent City is likely to have the Southern California sea lions for at least a few more months.
Dennis Wood, founder and medical director of the Northcoast Marine Mammal Center, which is one of only seven marine mammal centers in the state, said that "we are crossing fingers to not get an onslaught of harbor seal pups as well," since spring is typically the season the center takes in local strandings of that species.
After not securing a competitive grant that has provided about two-thirds of the center's funding for the last 10 years, Wood said the facility is "operating on a shoestring," but emergency federal funds will reimburse it for the costs of caring for sea lions from the "unusual mortality event."
Seals and sea lions should not be approached or handled by the public, as mothers will often abandon pups after there has been human contact.
Often harbor seals and sea lions that appear stranded are actually just patiently waiting for their mothers to return from fishing.
If you see a distressed marine mammal or one you suspect may be stranded, call the Northcoast Marine Mammal Center at 707-465-6265.
The center is always looking for more volunteers.
Reach Adam Spencer at firstname.lastname@example.org.