In the early 1700s, northern elephant seals were hunted to the brink of extinction for their blubber, and by the end of the 19th century, there were only 100 to 1,000 northern elephant seals left. They took refuge in Guadeloupe, Mexico and were protected by the Mexican government. Since the beginning of the 20th century, they are protected by law in Mexico and the United States. Later, they were protected in the United States in a tougher way, and their numbers eventually rose to more than 100,000 head.
The remaining northern elephant seals are experiencing population bottlenecks and are vulnerable to disease and pollution. In California, the northern elephant seal population is rising about 25 percent a year, and new populations are appearing. But their numbers have been affected by El Ni?o and the climate since then.
Northern elephant seal populations in California have risen dramatically over the past half century. For example, at the New Year's State Reservation, where they were not seen before the 1950s, the first northern elephant seals were seen in the 1960s, and now more than 1,000 are born there each year.