ANCHORAGE, Alaska (AP) - Northern fur seals have declined at the world’s largest rookery in Alaska’s Pribilof Islands, but they’re thriving at an unlikely location.

Numbers of fur seals continue to grow on Bogoslof (BOH-gohs-lawf) Island, a tiny land mass at the tip of an active undersea volcano in the Aleutian Islands.

The volcano two years ago spewed ash into the path of jetliners. Hot mud, steam and sulfurous gases continue to spit up from vents on the island.

Fur seals give birth and raise pups along the beach of the island that’s only about one-third the size of New York City’s Central Park.

Tom Gelatt of the National Oceanic and Atmospheric Administration says biologists in 2015 estimated there were 28,000 pups on the island. He says the 2019 estimate likely will be more than 36,000 pups.

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