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El Nino Starves Sea Lions, Seals

SPECIAL TO THE TIMES

On a cool, foggy day, a tiny California sea lion waddles painfully to a rock to die.

Shivering, the 6-month-old pup stretches her neck toward the sky, gathering some warmth from the weak rays of the sun. Around her, other scrawny, malnourished sea lions are sucking the last bits of milk from their mothers. On either side of her lie two decaying sea lion carcasses.

“That pup’s outta there,” said Bob DeLong, one of the nation’s leading experts in marine biology, watching from a sand dune on San Miguel Island. “She’s lucky if she makes it 24 hours.”

The 10-pound pup, whose wrinkled skin is too big for her body, is one of an abnormally high number of sea mammals--about 6,000 since the summer--dying on the island 50 miles off the Ventura coast.

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Though this pristine, desolate place normally provides an abundance of nutrient-rich plant and animal life--drawing the largest population of seals and sea lions south of Alaska--the island tells a different story this year.

In one of the most tangible manifestations of El Nino, oceanic warming has driven away the creatures’ favorite foods: squid, anchovies, herring and sardines.

Up and down the California coast, the food shortage is taking its toll on northern fur seals and California sea lions, both of which breed in summer and compete for the same food supply.

Three out of four fur seals born on San Miguel this June already have died, and DeLong expects to see the same fatality rate among the sea lion population by summer.

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DeLong, who works for the National Marine Fisheries Service in Seattle, has been stacking up the bodies here since midsummer. The death toll, he said, is no doubt similar on the half-dozen islands from San Francisco to San Diego where pinnipeds breed.

His job on San Miguel is to document the famine, not to save the dying animals. San Miguel has been targeted because the island has the California coast’s largest seal and sea lion population and studies have been done here since the 1960s.

What’s happening now, DeLong noted, is natural selection.

“Am I sad about it?” DeLong asked. “No. I’m just a watcher by the pond. It’s a privilege to be here to watch the good years and the bad years.”

But not everybody is willing to let the animals wither away.

Rescue groups--from Sea World in San Diego to a Sausalito-based organization--are poised along the coast to take in the starving seals and sea lions.

Federal law forbids them from going out to the remote island, lest they disrupt the habitat and take a pup from its mother. So they wait for the mammals to wash ashore in the annual spring migration, hoping some will survive that long.

“We realize from time to time that we come under fire from the general public wondering why we’re helping them if it is natural selection,” said Ann Bull, director of operations for the Friends of the Sea Lion Marine Mammal Center in Laguna Beach. “But no one asks why you take your loved one to the hospital.”

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There is no mystery to the deaths on San Miguel: The pups are dying because they aren’t getting enough milk from their mothers.

Lactating mothers can’t sustain their usual 250-pound frames because they are spending most of their energy in search of colder waters for their daily intake of 30 pounds of food.

“This is the most dramatic I’ve seen it,” said DeLong, 55, who was one of the first researchers to discover the proliferation of pinnipeds on the island in the late 1960s.

“Although it was bad [during the last El Nino] in 1982, we never really tracked it as well. When I came out here in July, I knew something was unusual when I started noticing how skinny these pups were.”

Of the 2,000 northern fur seals born on San Miguel since June, 75% have died, he said. Of the 23,000 sea lions born at the same time, roughly 20%, or about 4,500, were found dead in September, their corpses left to rot on the sand to feed the flies and gulls.

By June, DeLong expects the sea lion death rate to have jumped to 60% or 70%--up from a typical rate of 45% each year.

Federal researchers are only tracking mortality rates on San Miguel Island. But the toll could run as high on other islands where the mammals congregate--Catalina, Anacapa, Santa Rosa, Santa Barbara, San Nicolas and San Clemente in Southern California; the Farallon Islands near San Francisco and at Ana Nuevo near Santa Cruz. Of all the deaths, DeLong is most concerned with the fate of the adult females. If they die in huge proportions, virtually an entire generation of these mammals, who are typically fertile for 20 of their 25 years, will be gone.

“They’ve used up all their blubber on lactation,” DeLong said. “They’ve got no reserve energy and they’re just going to go back in that same damned ocean. . . . They’re going to need to find cold water, and I think that’s going to be a real difficulty.”

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Nevertheless, to scientists the deaths are a blip in the big picture.

Overall, the sea lion population has been increasing by 5% annually since the last El Nino, DeLong said. He estimates that between 85,000 and 180,000 sea lions breed on San Miguel and the other Channel Islands.

The fur seal population has been increasing since the 1950s, helped by an international treaty to stop slaughtering them. DeLong’s group estimates there are 1 million fur seals in U.S. waters, about 11,000 of them on San Miguel.

With those sorts of numbers, rescue groups are not likely to disrupt the environment by feeding a few starving seals and sending them back to the ocean. But many scientists believe the groups are wasting money that could be better spent reconstructing ecosystems destroyed by mankind or rehabilitating endangered species.

“I can’t say they are doing anything wrong,” said Jeff Laake of the Marine Fisheries Service, a division of the National Oceanic and Atmospheric Administration. “But they’re largely wasting their time. There is so much mortality that occurs, what will be gained by saving a handful?”

Peter Howorth, director of the Santa Barbara Marine Mammal Center, has a simple answer. “Saving the entire population would be a disservice from a biological standpoint,” he conceded. But what a group like his can do, he said, is mitigate human impacts.

“We can’t save all the ones that humans catch in gill nets or ruin their habitats,” Howorth said. “So we try and save the numbers that we can even if it is a natural event. It’s like a bank. You borrow from one account and you put it into another.”

Such organizations work with the permission of the federal fisheries agency, which hands out permits to private groups that save stranded mammals on California’s mainland.

“We rehab the animals because the public wants it,” said Joe Cordaro, a wildlife biologist who heads the “stranding network” for the agency in Long Beach. “There are taxpayers out there who want us to save these mammals.”

The rescue workers are subject to the 1972 Marine Mammal Protection Act, which prevents them from going to San Miguel Island.

So far this year, only a few of the mammals have made it to the coastline. Their usual feeding season will take them there in the spring, when Cordaro expects to see many sick or dead sea lions and fur seals washed up on the shore.

As a biologist, Cordaro has his own “internal struggles” about whether it is good to “take them in, fatten them up and send them back out in the same situation.”

For that reason, Susan Andres, communications director for the Marine Mammal Center in Sausalito, said her center may delay releasing the mammals it cares for until there is enough food.

Established in 1975, it spends $1.5 million of its $2-million annual budget on rehabilitating sick pinnipeds, feeding them, nurturing them in pens, taking their blood work and sending them back to the wild.

Last year, the center rescued 480 sea lions, half of them pups. Back in 1982, when there was a smaller El Nino effect, the center took in about 800 sea lions.

It makes no difference to Andres, or to the center’s 800 volunteers, that sea lions and seals are dying this year because of the naturally occurring conditions.

“We will rescue any animal that we can,” Andres said. “You can’t necessarily tell if the injury or illness was human-caused or not.”

The rescue groups know they can’t go out to the islands and save every creature. “But, if the law wasn’t there, we would go out there and do it,” said Bull, of the Friends of the Sea Lions.

Bull recognized, however, that the policy is there for a reason: Many well-intentioned people would go out to the islands and rescue healthy pups that simply were waiting for their mothers to come back.

For scientists, meanwhile, the unfolding situation provides a key opportunity for research.

While doe-eyed seals and sea lions draw the most attention, the Channel Islands Marine Sanctuary is looking at the big picture of El Nino’s sea surface temperatures surrounding San Miguel and four other Channel Islands.

For instance, the staff at the Santa Barbara-based sanctuary are collecting data on the decreasing kelp forest surrounding the islands. Without the golden algae, sea urchins have nothing to feed on, a trend that, in turn, causes problems for the fishing industry.

“We want people to understand this ‘ecosystem approach’ from a larger perspective,” said sanctuary manager Ed Cassano.

“We can brace ourselves for a man-made effect, like an oil spill . . . or ships colliding,” he said. “But all of us are asking, ‘How are you going to look at El Nino?’ . . . because we can’t prevent it from happening. Because you can only manage man, you can’t manage the environment.”

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

Victims of El Nino

The California sea lion and the northern fur seal breed in the summer on San Miguel Island and others off the California coast. Thousands of pups have died this year as El Nino’s oceanic warming effects have driven away much of their food supply.

CALIFORNIA SEA LIONS

* Weight: Adult males average 8 feet long and 800 pounds. Adult females average 5 feet long and 250 pounds. Pups are usually 2 feet long and 13 to 18 pounds.

* Body Shape: Sleek bodies with elongated necks, tapered snouts and obvious ears. Adult males have a crest on their heads.

* Population: Scientists estimate that there are between 85,000 and 180,000 sea lions breeding on San Miguel and other Channel Islands. After breeding, adult males go to Northern California and British Columbia. Adult females swim south to Ano Nuevo and the Farralon Islands. Many of the pups stay around the Central Coast.

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NORTHERN FUR SEALS

* Weight: Adult males average 7 feet long and 400 to 600 pounds. Adult females average 5 feet long and about 100 pounds. Pups are 2 feet long and 10 to 12 pounds.

* Body Shape: Noses are pointed with short muzzles. The profile of the head is convex from nose to neck. Bodies are covered in fur, and their hind flippers are longer than sea lions’. They also have obvious ears, which are low on the sides on their heads. Males have a furred crown.

* Population: Scientists estimate that there are 1 million fur seals in U.S. waters, about 11,000 of them on San Miguel Island. After breeding, fur seals spend the rest of the year feeding in the open ocean.

Source: Guide to Marine Mammals of California


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