A whale swims off the Valdes peninsula, Argentina. After summering in the Arctic, whales return to the southern seas each winter to reproduce. From July to November, whales mate and bear their young along the coasts of the Valdes Peninsula in Argentina. Until the 1950s, this migratory marine mammal was extensively hunted for its meat and the oil extracted from its fat, which brought it to the edge of extinction. Protective measures were adopted after international attention was focused on the problem in 1937. In 1982 a moratorium was declared on whale hunting for commercial purposes, and in 1994 the southern seas became a whale sanctuary. After decades of protection, 7 of the 13 whale species, of which only a few thousand remain (10 to 60 times fewer than in the early 20th century), are still endangered. [ map ] (© Yann Arthus-Bertrand