Unlike whales and sea lions that rely on a layer of blubber to keep them warm in the icy North Pacific Ocean, the sea otter is protected by its thick fur. While we humans have between 20,000 to 100,000 hairs on our heads, the sea otter has from 600,000 to a million hairs per square inch. It’s this luxurious fur that made the sea otters so attractive to trappers, who brought the otters to near extinction until stopped by the International Fur Seal Treaty of 1911.[Editor’s Note: An updated version of this topic can be found here: Sea Otters]
