El Nino Brings Natural Disaster to Sea Creatures

After being rescued half-starved from the sea and fattened up by humans, the young elephant seal called Rossi was in no rush to plunge back into the surf when her cage was opened on a sandy cove here one recent day. She looked sadly over a shoulder before waddling slowly to the shoreline.

If Rossi had reservations about returning to her watery home, it’s no wonder. The fish she eats are scarce, so sparse that hundreds of dead or emaciated sea lions and seals have been washing ashore in record numbers along the California coastline this spring. Sea mammal rehabilitation centers, like the one in Laguna Beach that took Rossi in, are bulging with distressed animals.

Mother Nature is clearly in disarray, and scientists place the blame on El Nino, a periodically recurring shift in the currents of the Pacific Ocean. The phenomenon appeared suddenly along the California coast in January as the cold, southward current near the shoreline reversed, bringing in warm waters from the tropics that have heated the top layer of the sea 4 to 6 degrees above normal.

Deprived of the cool, wind-whipped current that usually brings upwellings of nutrients to the sun-lit surface of the ocean, the microscopic plankton that form the first link of the coastal food chain have failed to thrive. In turn, fish that feed on the plankton have suffered. Fish that prefer cool water, including anchovies that are the favorite fare of sea lions and brown pelicans, have become scarce. Biologists believe some of the fish may have moved farther north, to deeper water or out to sea.

“The food chain has collapsed or isn’t developing this year,” said Robert Lea, a marine biologist for the California Department of Fish and Game.

The results are vivid. In Monterey, young sea lions crowding the harbor in search of food began venturing into a public parking lot and restrooms near a boat launching area. Befuddled city officials were forced to erect a fence to keep them out.

Yearling sea lions that normally weigh 70 to 90 pounds are being pulled out weighing a skinny 30 to 40 pounds. “You can see their ribs,” said Lance Morgan, a marine biologist at Marine Mammal Center in Marin County.

Sea mammals are not alone in their suffering. Many of the state’s sea birds this spring aren’t bothering to nest or are abandoning their eggs, and many species of rockfish, an important catch for commercial fishermen, didn’t spawn this year along the central California coast.

The strength of the sea change, oceanographers say, at times has equaled the severe El Nino conditions of 1982-1984, which caused sharp--albeit temporary--declines in numerous marine animal, bird and fish populations. The unseasonably warm ocean current is expected to dissipate along the California coast by winter.

While cool-water fish have become scarce, tropical species have appeared far north of their usual haunts. In recent months, warm water flying fish have been spotted in Monterey Bay. Barracuda generally found in Mexican and Southern California waters this time of year have been caught near San Francisco.

There are some benefits from El Nino. The warm water is prompting a resurgence of sardines, and the Department of Fish and Game says there is very good kelp bass fishing from Santa Barbara to Mexico because these fish get hungrier when their body temperature rises.

Southern California sport fishermen gleefully anticipate the northward pilgrimage of such tropical game fish as bigeye tuna, yellowfin tuna, skipjack and dorado, some of which have already been caught by fisherman sailing south just 50 miles from San Diego.

But for California’s marine mammals, El Nino is an immediate and undisputed tragedy, especially for the young.

Rehabilitation centers that rescue stranded sea lions, harbor seals and other marine mammals say they typically pull ailing pups from the water each spring when they are hard pressed to compete for fish with larger and more experienced adults. But this year, the numbers of stranded young have exploded. Only recently weaned from their mothers’ milk, hapless sea lion yearlings have less lung capacity for deep-sea diving and they are less skilled hunters.

Since March, weary seals and sea lions have been arriving at a record-breaking clip at Laguna Beach Friends of the Sea Lion Marine Mammal Center.

Two volunteers last Monday afternoon struggled to rescue a sickly sea lion that clung to a jagged rock at Crystal Cove State Beach. They sloshed through the surf, wrestled their slippery catch into a net and dragged it onto shore.

Despite the animal’s writhing, which twisted the net into a snarl, the workers got the 45-pound pup into a cage and hoisted it onto a pickup truck for a trip to the center.

“Believe me I am tired and soaked up to here,” Robyn Battershill, one of the volunteers, said before climbing into the truck bed next to the sand-caked sea lion. “It’s real difficult to get them off a rock like that. A lot of times we lose them and they go back to the ocean.”

The same day rescuers also captured two beached harbor seals at Laguna Beach and Dana Point, pushing the sea mammal population at the Laguna Beach center to 85, which is a record for the 21-year-old facility.

Sea World’s mammal rehabilitation center in San Diego has taken in 244 beached animals that were rescued between Los Angeles and the Mexican border, compared to 239 for all of 1991.

In Northern California, however, the mammal stranding problem is far worse. In the first six months of this year, the Marine Mammal Center in the San Francisco Bay Area has already recorded more rescues than it did a decade ago, pulling 480 troubled sea lions and other marine mammals from 1,000 miles of coastline from the Oregon border to San Luis Obispo. In 1982-83, 383 animals were rescued.

As a result of El Nino, more sea lion yearlings than usual have been departing Southern California, where they were born in Channel Islands rookeries, and heading up the coast in a quest for fish.

Whereas normally in June there are no more than 50 sea lions on the rocks of the Monterey breakwater, currently there are 1,400 of the playful animals--enough to attract busloads of tourists with cameras.

The Marine Mammal Center’s headquarters in the Golden Gate Recreation Area is caring for 210 of the animals. They’re housed in pens with fiberglass pools, cooled with whirlybird sprinklers, fattened with herring and treated for respiratory ailments and other health problems at a cost of $1,500 a day funded with donations from across the nation.

Experts say that sea lions are extremely vulnerable to this year’s El Nino largely because of their burgeoning population. The animals now number 110,000 statewide and have been multiplying at a rate of 5% a year for the last two decades, abetted in part by the Marine Mammal Protection Act of 1972. The result has been more animals vying for fewer available fish. Sea lions are also less powerful divers than harbor seals and elephant seals, which can forage in deeper water for fish.

Unable to fend for themselves, young sea lions frequently try to nab fish being pulled aboard fishing vessels, getting tangled in hooks or nets. Or worse. The Bay Area’s Marine Mammal Center since January has treated 40 to 50 sea lions with gunshot wounds. By law, commercial fisherman can shoot sea lions if they are destroying their catch or gear.

Many sea lions are also washing up dead, according to lifeguards who find their remains.

At Bolsa Chica State Beach in Orange County, for instance, lifeguards in April and May buried 80 sea mammals, mostly sea lions, that the waves carried ashore. Only half way into June, the bodies of another 27 sea lions and four harbor seals were found and buried. “I’ve been here 18 years and it is the most I have ever seen,” said Gregory W. Scott, lifeguard supervisor at the beach.

Some sea bird rehabilitation centers, meanwhile, say they have been inundated with calls in recent weeks to help starving birds.

Wendy Turner, curator of birds at Sea World, said in the last six weeks, 61 pelicans have been sent to Sea World to be rehabilitated, compared to just four during the same period a year ago. “We are predicting a very heavy summer,” she said.

Pelicans are descending on marinas in Orange County in a desperate search for food and are being injured by fishing hooks as they dive after fishermen’s bait.

This spring is also shaping up as poor season for sea bird reproduction. Dan Anderson, chairman of the department of wildlife ecology at UC Davis, said during field research he discovered that in the southern part of the Sea of Cortez, pelicans, cormorants and gulls have in many cases abandoned their nests or never showed up for the beginning of the breeding season in March and April.

Instead of hatching and raising young, some of the birds have left the gulf nesting grounds to begin an early migration north. “They are following the food,” said Anderson.

Nor are conditions any better on the Channel Islands. Frank Gress, a UC Davis research biologist who has been studying California brown pelican nesting on Anacapa Island since 1978, said brown pelicans have not had a very successful breeding season on Anacapa for several years, apparently because of a shortage of anchovies.

El Nino has made foraging for the pelicans on Anacapa even more difficult, with the result that the birds built only 1,500 nests on the island this year, compared to 5,300 last year. About 70% have been abandoned.

Gress said when he was banding pelican chicks on Anacapa last week, he found scores of the young birds have starved to death. Most of those still alive were emaciated.

“Only about 10% of the chicks we banded were of normal weight,” he said.

Cormorants were also not doing well, he said. One species, the Brandt’s cormorant, has mostly abandoned breeding efforts throughout the Channel Islands.

Trudy Ingram, wildlife biologist in charge of the sea bird monitoring program at Channel Islands National Park, said she is also concerned about the xantus murrelet, a very rare and beautiful bird species that normally has a large nesting colony on Santa Barbara Island. She said this year the birds started nesting late and their hatching success is very poor.

“It is a little more serious for a rare species to have this sort of setback,” she said.

Bill Sydeman, program director for the Point Reyes Bird Observatory on the Farallon Islands off the coast of San Francisco, tells another discouraging story: Six of the 11 sea bird species that breed on the islands have had far fewer than usual chicks this spring.

Sydeman said the harshness of El Nino’s impact on sea bird breeding was unexpected. “Based on the information that we had, we thought it would not be that severe, “ he said. “But what we are seeing is as severe conditions as we have ever witnessed. This is as bad as it gets.”

A Coastal Calamity

As the warm ocean currents of El Nino have embraced the coast, sea life has suffered. The tropical currents, which warm the ocean up to 650 feet deep, generally carry fewer nutrients than the colder waters from the north. The result has been less plankton and fewer fish for sea lions to eat.

A Normal Year

Cold ocean currents headed south in the spring usually combine with northerly winds to cause an upwelling of nutrient-rich water from the deep sea to the shallower, sun-lit water. Plankton, the foundation of the marine food chain, feed on the nutrients.

With El Nino:

1. Upwellings of nutrient-rich water do not occur due to the presence of the El Nino current.

2. Without the nutrients, plankton is much more scarce, existing at lower depths.

3. Some types of fish, such as halibut and rockfish, move to deeper waters in search of plankton.

4. Anchovies, a staple of the sea lion diet, move north out of Southern California waters or farther out to sea. Shallow-water squid die.

5. Sea lions, which usually dive 100 to 300 feet, can’t get deep enough for a good meal.

The Sea Lion Scene

California sea lions (Zalophus californianus) are known for their intelligence, playfulness and noisy barking. Also:

* Males reach 1,000 pounds, seven feet in length; females grow to 250 pounds, five feet in length.

* Pups are born in June and July, weigh 12 to 14 pounds.

* Sea lions have external ear flaps and large flippers, which they use to move about on land.

* They prefer to eat anchovies and squid but also eat octopus, herring, juvenile rockfish and mackerel. A yearling eats about 5 to 10 pounds of fish per day; adult females eat about 25 pounds, bulls up to 60 pounds.

* They are found from Vancouver Island, Canada, to the southern tip of Baja California.

Sources: Scripps Institution of Oceanography; National Marine Fishery Service; Marine Mammal Center Education Department

Researched by LESLIE BERKMAN / Los Angeles Times

Sea Starvation

Since El Nino kicked in, marine mammal centers along the California coast have documented record numbers of sea lion rescues--and deaths:

* Laguna Beach Friends of the Sea Lion Marine Mammal Center: 85 sea lions and seals have been treated already this year, a record for the 21-year-old facility.

* Sea World’s mammal rehabilitation center, San Diego: 244 beached animals rescued between Los Angeles and the Mexican border, compared to 239 for all of 1991. In the last six weeks, 61 pelicans treated at Sea World compared to four during the same period a year ago.

* Marine Mammal Center, Marin County: 480 troubled sea lions and other mammals rescued, compared to 383 during an El Nino a decade ago. More than 40 of the animals have been treated for gunshot wounds, probably inflicted by fishermen.

* Bolsa Chica State Beach: Since April, lifeguards have buried more than 100 dead sea mammals, mostly sea lions, carried ashore by the waves.

* Anacapa Island: Birds have built only 1,500 nests this year, compared to 5,300 in 1991.

Sources: Scripps Institution of Oceanography; National Marine Fishery Service; individual organizations