SAN FRANCISCO — Just three years after she was found covered in oil and near death, a California sea otter called Olive is a new mom — another milestone for the first otter to survive an oiling in the state.
The California Department of Fish and Game said Friday that "Olive the Oiled Otter" was spotted recently swimming on her back with a pup resting on her belly.
"Olive is an attentive mother, frequently grooming, nursing and holding her pup," the agency said in a statement.
The birth continued the remarkable story of the animal rescued in 2009 from a beach near Santa Cruz. And the pup was welcomed after a recent state and federal study found tepid growth of the threatened California sea otter population on the Central Coast.
Scientists say oil is especially harmful to the species that has the thickest coat of any mammal. When it's damaged by oil, the skin is exposed to cold water, which can lead to hypothermia and death because otters don't have a layer of blubber like other marine mammals.
The U.S. Geological Survey said there are 2,792 sea otters left in the California population, which stretches from Morro Bay to Half Moon Bay along the Central Coast.
The animals once ranged from Mexico to Alaska but were hunted to near extinction in early 20th century for their fur
After Olive was bathed in olive oil — hence the name — and fed by fish and game veterinarians, she was outfitted with a microchip and transmitter and released back into the wild, where scientists have tracked and studied her.
Officials believe the oil that coated Olive came from natural seepage off the Monterey coast. Veterinarians understand the immediate health effects of oil on wildlife, but little is known about long-term impacts.
That makes Olive and her baby especially interesting to marine biologists.
"Few animals are available for long-term follow-up," said Bill Van Bonn, a veterinarian at the Marine Mammal Center in Sausalito, a group that rescues and rehabilitates marine mammals. "It illustrates the value of rehabilitation work."
Scientists have been tracking Olive since her release and conducting regular checkups.
"In recent months, she's been known to frequent a surf spot in Capitola known to locals as 'The Hook,'" Laird Henkel, manager of the Santa Cruz-based marine mammal center, said in a statement. "Olive has successfully re-integrated back into the wild, socializing with other otters and foraging normally."
Scientists discovered she was pregnant when she was brought in for a checkup in early August. Afterward, Olive moved from her regular spot at The Hook and became hard to find for a few weeks.
On Sept. 7, her transmitter beacon showed she had returned to her regular spot amid the kelp and surfers. When scientists went to check on her, Olive was floating on her back, cuddling her pup.
Since her release, Olive has gained a Facebook following, with hundreds of people offering congratulatory comments to the new mom.