Seal and large whale populations have been severely depleted but are now legally protected. Marine mammals are top predators in the marine ecosystem and feed primarily on small pelagic fish or squid. Most Peruvian small cetaceans and pinnipeds feed primarily on anchoveta Engraulis ringens which was depleted by a combination of overfishing and a strong El Nino event. The lower prey availability may prevent marine mammal species from recovering to their former population levels. -from Authors