The Dramatic Effect of El Nino on Southern Californias Seal and Sea Lion Population :: Animals Nature Environment essays Climate

At the beginning of our winter season, El Nino left some dramatic effects on our seal and sea lion population here in Southern California. Since June of 1997, about 6,000 sea mammals have perished on this San Miguel Island, 50 miles off the Ventura coast. This island is home to the largest population of seals and sea lions south of Alaska. Scientists estimate that there are approximately between 85,000 and 180,000 California sea lions breeding on this island and other Channel Islands. There are about 11,000 Northern Fur Seals on San Miguel Island. The adult sea lions go to northern California and British Columbia after they breed, while the pups are left behind around the central coast. In one of the most physical demonstrations of El Nino, oceanic warming drove away much of their food supply: squid, anchovies, herring, and sardines. The pups are spending most of their energy in search of colder waters for their daily intake of 30 pounds of food. Experts in marine biology are strictly observing and documenting the famine, not attempting to rescue the dying animals. They have been conducting studies on this island since the 1960s. Several rescue groups, such as Sea World located in San Diego, were ready to bring back the starving pups. However, the 1972 Marine Mammal Protection Act prohibits them from going to the remote island and disturbing their natural habitat. Experts would rather wait for the mammals to get washed up ashore than to separate a pup from its mother. The goal is to minimize human impacts. Scientists are now trying to learn from the mistakes they made when studying the effects of the 1983 El Nino. There was a research project conducted on the marine ecosystem at the Punta San Juan de Marcona sea lion reserve, a remote point of land on the coast about three hundred miles south of Lima, Peru. The project consisted of an in-depth study of the sea lion and the ecosystem it inhabits; it focused primarily on the behavior of more than fifteen thousand sea lions, the largest sea lion colony in the South American Pacific. Documenting the sea lions living traits for over 10 years, the biologists are also observing behavioral changes produced by El Nino, the same Pacific current that altered oceanic conditions. When El Nino dampens the point in warmer water, the sea lions' prey swims deeper. Consequently, the pups remain with their mothers longer, until they are able to dive themselves to hunt for food.