SANTIAGO – Chilean authorities are investigating the causes of a higher mortality rate among a population of sea lions along the country’s northern Pacific coast where recently about 300 of the animals have been found dead or dying.

The situation is unfolding in Punta Patache, 71 kilometers (44 miles) south of Iquique and, according to press reports, experts are uncertain why the deaths – most of which have been among young sea lions – are occurring.

While some attribute the deaths to natural causes, other experts point to the lack of food in the area, and ecological groups say that certain mining operations or an electricity plant near the sea lions’ range are responsible in some way.

The local office of the National Fisheries Service, or Sernapesca, attributed the deaths to a lack of food in the Pacific because of the El Niño climate phenomenon, a circumstance that forces the sea lions to have to travel up to 100 miles out to sea to find food.

The younger animals cannot swim those distances and thus have been the most affected, according to Maria Soledad Tapia, the regional director of Sernapesca.

However, in the judgment of the environmental group Atacama Sustentable, the situation is due to the sea lions consuming contaminated fish, the result of waste disposal by a molybdenum plant operating near the zone.

“The most probable thing is that the food for these individuals is contaminated, which would be affecting their immunological system,” marine biologist Sonia Moreno told the Iquique daily La Estrella.

The plant belongs to foreign-owned mining firm Collahuasi, which last March was fined by the Regional Environmental Commission for an infraction of environmental regulations.

Navy Capt. Alvaro Vicencio Andaur, the maritime governor of Iquique, said he agreed with the thesis of the lack of food associated with El Niño, adding that the dead sea lions do not number in the hundreds, “but rather a few dozen,” most of them between 7 and 8 months old.

He said that to the lack of food must be added the heavy seas that in recent weeks have prevailed in the zone, a situation where the weakened mammals cannot bear up against “the forces of nature” and succumb.

He added that the normal mortality rate for sea lion young is about 30 percent, but at present among this population it stands at about 70 percent.

Also adhering to this opinion was marine biolgoist Cristian Hudson, director of the Center for Research and Development of Marine Projects, who criticized the environmental groups for making accusations he described as “very premature and sensationalist.”

After saying that dead sea lions had also been found in other places, like Arica, 200 kilometers (124 miles) farther north, Hudson said that the scarcity of food also could be explained by the human overexploitation of the anchovy, a small fish that is the sea lions’ main food and the prime ingredient in the manufacture of fish meal. EFE