Effects of reduced genetic variation in elephant seals

The northern elephant seal almost became extinct in the late 1800’s following harvesting by whalers and sealers for their blubber which contains oil. A small colony of between 20 and 100 individuals survived on Guadalupe Island off Baja California. From that small colony have come the approximately 160,000 elephant seals found on the Pacific coast today. That dramatic shrinking of the population resulted in a reduced genetic diversity among the survivors – a “genetic bottleneck.”