Sept. 4 (Bloomberg) -- Sea lions are starving to death in unusual numbers along Chile’s northern coast, signaling the weather shift known as El Nino is taking hold in the Pacific.

The El Nino effect, which is bringing warmer water to South American shores, seems to be driving away fish the mammals eat. Evidence of that is found in the autopsies of emaciated pups, said Walter Sielfeld, a professor of marine science at Arturo Prat University in Iquique, Chile, who examined the sea lions.

The warming trend is deepening the woes of Chile’s $4 billion fishing industry, already ravaged by a salmon virus that has hurt exporters. In the last 30 years, El Ninos have sparked deadly floods and landslides from Ecuador to California, drought in Africa, wildfires in Australia, causing billions of dollars in damage, according to the U.S. National Academy of Sciences.

“We think it’s El Nino coming,” Sielfeld said, basing his analysis on autopsies that found sea-lion pups had empty bellies and no adipose tissue, the fat that insulates their bodies.

“The sea lions are a good indicator” the weather phenomenon that occurs every few years is emerging again, the professor said in an interview. “There have been a huge number of deaths -- it’s not normal.”

More than 1,000 sea lions have been found dead, Chile’s national fishery service said in an Aug. 28 statement.

The die-off, which echoes similar deaths occurring in California, is among the first concrete effects of El Nino, which starts when warm water from the western Pacific shifts along the equator to the eastern Pacific. The nutrient-rich cool water that usually wells up from the ocean floor is blocked, fish decline sharply or move elsewhere, then seabirds and mammals often starve.

Fish Scarcity Worsens

The start of El Nino in Chile this year is exacerbating a scarcity of fish, said Jose Sanchez, a fishermen’s union official in Mejillones, Chile, 700 miles north of Santiago, where more than 500 sea lion pups from the Otaria flavescens species have been found dead, according to an e-mailed statement last month from the fishery service.

“The sea lions are suffering in the same way we are,” Sanchez said Aug. 24 as he watched a starving pup drag itself along a beach. “We see this daily. All along the coast the sea lions are dying and we’re hungry too. All the species are disappearing.”

Fish such as anchoveta and mackerel appear to have migrated in response to a rise in sea temperatures, forcing mothers of sea lion pups born from January to March to travel further in search of food, said Antonio Palma, a biologist with the National Fisheries Service in Valparaiso, Chile. Almost all the dead animals were three to six months old, Palma said.

Pups ‘Still Breastfeeding’

“The pups are still breastfeeding so they’re waiting for their mothers to come back and feed them,” Palma said in an Aug. 31 telephone interview. “The females either don’t return or they came back in bad condition so we have some dead females, too. It’s likely the numbers will go up.”

Stocks of pelagic fish -- those that inhabit the open ocean rather than coasts or the sea floor -- have plummeted in the two regions where most of the sea lions died, data from Chile’s national fishing service shows.

Catches of species led by anchoveta, jack mackerel and chub mackerel fell 97 percent in July to 1,108 tons from 40,517 tons in June. In the first two weeks of August, the latest data available, fishermen caught just 2.2 tons along 500 miles of coast, according to the data obtained by Bloomberg News.

Plummeting Fish Catch

Ships caught 0.3 tons of fish a day off north Chile in early August, down from 2.1 tons a day in July and an average of 16.4 tons daily in the first half of the year, the figures show. That compares to 9.1 tons a day in August 2005, an average year.

The sea lion deaths have yet to affect neighboring Peru where scientists expect a relatively mild El Nino this year, said Elisa Goya, a researcher at Imarpe, the Peruvian Institute of the Sea in Lima.

El Nino’s weather pattern is expected to strengthen and last into 2010, causing disruptions from Indonesia to the Caribbean, according to the U.S. Climate Prediction Center. The last strong El Nino in 1997 and 1998 helped cause flooding in California and forest fires in Indonesia and Mexico.

This year, Indonesia plans to hoard rice and Australia’s farmers are braced for dry weather that may cut wheat output by 25 percent. Ranchers in Argentina hope El Nino will help save their cattle and boost the soybean harvest as precipitation on the pampas ends the worst drought in a century.

‘Signs of Strengthening’

“We have weak El Nino conditions right now across the Pacific and we have seen some signs of strengthening,” said Mike Halpert, deputy director of the Climate Prediction Center in Camp Springs, Maryland. “The strongest impacts typically come during the winter in the Northern Hemisphere. Right now it’s pretty hard to say how strong this event is going to be.”

In California, where El Nino isn’t expected to strike the coast until next month, scientists are studying the starvation deaths of thousands of Zalophus californianus sea lions in May and June on the Channel Islands near Santa Barbara.

Pacific trade winds died in May for the first time on record, slowing or stopping the upwelling of nutrient-rich water, said Robert DeLong, head of the California program at the National Marine Mammal Laboratory in Seattle.

The lowest upwelling in 60 years of records caused prey- fish to leave the area and at least 70 percent of the 12,000 to 15,000 sea lion pups born this year in a sample area on San Miguel Island in the Channel Islands died, DeLong said in an Aug. 28 telephone interview.

The Marine Mammal Center, a non-profit rehabilitation center for sick animals based in San Francisco, has taken in more than 1,300 cases this year, most of them sea lions, said Bill Van Bonn, the center’s staff veterinarian, compared with 1,200 during all of 1998, its previous busiest year.

“It’s almost like El Nino conditions but too early,” Joe Cordero, a biologist at the National Oceanic and Atmospheric Administration in Long Beach, California, said in an Aug. 27 telephone interview. “If the El Nino continues to develop it’s going to get much, much worse.”

To contact the reporter on this story: Sebastian Boyd in Santiago at sboyd9@bloomberg.net

Last Updated: September 4, 2009 00:01 EDT