EXCLUSIVE: Fur Seals Are Back From the Brink on California Islands | National Geographic

The northern fur seal was a top predator in this area, and 150,000 of them were removed from the ecosystem. My name is Jim Teats, and I'm a biologist for Point Blue Conservation Science. I work on Southeast Farallon Island, which is 30 miles west of San Francisco.

In the eighteen hundreds, there were a lot of sealers that came to the island, hunting fur seals and other seals for the pelts. They were completely removed from the island; there were basically none left. Fur seals are pretty small compared to a lot of the other seals. Individuals have been seen by biologists since 1970, and around there, more and more individuals started showing up. They finally started breeding in 1996.

This survey's been going on for a few decades now, but the one problem with this survey is that we can't see what's going on over at West End, where all the fur seals mostly are. So we go over there twice a month to count them all from much closer, and that way we can get a much more accurate count as to how many there are. This population has been growing exponentially for the past about 20 years or so.

There were over a thousand now total individuals at this colony. Our peak counts now are up around 1,100 to 1,200 individuals and about three to four hundred pups. The population is actually probably quite a bit larger because, at any given time, most of the fur seals are probably out in the water hunting or just staying cool. They have an extremely dense fur, and that allows them to be pretty much impervious to the cold water when they're swimming around.

It looks like there's a lot of them over on Indian Head and then down in the water also. Some of the rookies apparently up in Alaska and islands have been tagging individuals. Then also on San Miguel Island, when that colony first started, people started tagging those animals as well. The tag is either a small piece of plastic or metal; it's like an earring essentially with a number on it.

Probably 99% or more of the tags we see here are from San Miguel Island. I've seen one tag from the Commander Islands from Russia, which is incredible just to think of the fur seal—a small seal— swimming all the way from Russia all the way over to Southeast Farallon Islands. Amazing!

We're not 100% sure that the population will recover to the level it used to be. You know, the ecosystem is not as healthy as it once was. The population could top out and, you know, stay around 20,000 to 30,000. It'd be great to top out at 150,000, but there's just no knowing at this point what that's gonna be.