Two gray whales show their rostrums at the San Ignacio Lagoon, Baja California Sur state, Mexico on February 28, 2010. Although a debate is now raging among some whaling nations to begin limited hunting again, the Pacific gray whales have been protected since 1947, and are at the center of a growing whale-sightseeing industry. Their numbers have dropped by a third, from around 26,000, in the late 1990s. Scientists say that the decline was caused by melting artic ice impacting on their food chains, which include small fish, crustaceans, squid and other tiny organisms. A small-scale whale-sightseeing industry was developed in the remote spot of San Ignacio Lagoon, off Mexico's northwest Baja California peninsula, where grey whales breed and nurse their calves each year after migrating thousands of miles from Canada and Alaska.