Thank you for signing up to our email!

Now, before you leave, do you want to make a seal's day?

Guadalupe fur seals

Guadalupe fur seals have a very limited range along the coast of California and Mexico. Their sole breeding ground is on Guadalupe Island, approximately 150 miles off the west coast of Baja California.

The Guadalupe fur seal (Arctocephalus townsendi) was listed as threatened under the Endangered Species Act in 1985. The National Marine Fisheries Service (NMFS ) classifies it as a "strategic" stock. This is defined within the Marine Mammal Protection Act as a marine mammal stock

  • for which the level of direct human-caused mortality exceeds the potential biological removal level;
  • which, based on the best available scientific information, is declining and is likely to be listed as a threatened species under the ESA within the foreseeable future; or
  • which is listed as a threatened or endangered species under the ESA, or is designated as depleted under the MMPA.

Source: NOAA Fisheries Protected Resources Glossary

The Guadalupe fur seal was hunted almost to extinction in the 18th and 19 centuries. It was valued for its luxuriant fur, as well as oil that could be rendered from its blubber. The island of Guadalupe, off the coast of Baja California, is the sole breeding ground for Guadalupe fur seals. The Mexican government created a biological reserve on the island in 1922 and increased the protected status in 1975, declaring Guadalupe Island to be a pinniped sanctuary.

The current population of Guadalupe fur seals is estimated to be at least 34,000. It is increasing by small amounts each year and the the species is slowly recovering from the brink of extinction.


"Frequently, many thousands of seals congregate on the same island. They prefer remote, isolated situations, often upon barren rocks or islands, the shores of which are surrounded by a high surf, in which they delight to play."
    Charles M. Scammon, 19th century seal hunter

The Marine Mammal Center has rescued a total of 95 Guadalupe fur seals sine 1975, a relatively small number. Guadalupe fur seals are pelagic animals, meaning they spend most of their lives out at sea, so it is rare for them to haul up on a beach. Their range is also very limited, stretching from the tip of Baja California up to Northern California. Most of the animals rescued by the Center have been pups, although two adult females were rescued in 2014. One of them was Sterling Archer, whose story is featured below.

T Rex
Guadalupe Fur Seal

In 2015, a large number of Guadalupe fur seals stranded on the beaches of California after facing the same food shortages that have been plaguing California sea lions. Among them was T Rex, a male pup that was found emaciated and lethargic at San Francisco’s Ocean Beach. He was nursed back to health for three months at the Center and then released back to the ocean at Chimney Rock in the Point Reyes National Seashore. Like many of the other Guadalupe fur seals that were treated and released that year, T Rex had a satellite tag attached to him so his movements could be tracked. He headed north after his release and was tracked at Vancouver Island several months later. This provided an invaluable amount of knowledge to researchers at the Center.

Sterling Archer
Guadalupe Fur Seal

Sterling Archer was an adult female Guadalupe fur seal that was rescued in February, 2014 at Del Monte Beach near Monterey. She was observed to be lethargic and emaciated by beachgoers. She was brought to the Center's hospital in Sausalito, where she weighed in at 97 pounds. This is only slightly below the average weight of 100 pounds for an adult female Guadalupe fur seal, although Sterling Archer appeared to be suffering from malnutrition. She was diagnosed with domoic acid toxicity, a condition resulting from harmful algae blooms. This is caused by the neurotoxin domoic acid, which is produced by diatoms in the genus Pseudo-nitzschia. After spending a month at the Center, she was deemed ready to go back home. A crowd of onlookers, including noted marine biologist Sylvia Earle, came to watch her release at Rodeo Beach on March 28, 2014.

Want to learn more about marine mammals?

Sign up for the monthly E-Newsletter from The Marine Mammal Center.



Learn more about Guadalupe fur seals.

Adopt-a-Seal LilaRach.

Learn how you can Take Action to help marine mammals.

COVID Response

Focusing on safety in our core work.

Adopt a Seal

Your symbolic adoption helps our patients thrive.

Our Commitment

Expanding work on social and environmental equity.