A North Pacific fur seal that spends much of its time in the open ocean. It comes ashore on island beaches to breed and rest.
It has dense fur and a short muzzle. Adult males are much larger than females and have dark brown to black coats.
A study tracked five juvenile and subadult male northern fur seals as they moved north from wintering grounds in the Sea of Japan. Their tracks showed a slower, curving stay phase and a faster, more directed transit phase. Foraging-related behavior was more likely near continental shelf breaks and in the Kuroshio–Oyashio Transition Zone where sea-surface temperatures were 8–13°C.
Transit behavior appeared more often below 2°C and above 13°C, and seals also tended to transit near anticyclonic eddy edges. The authors suggest those eddy edges may help seals travel in a directed way while using less energy. The findings come from five juvenile and subadult males wintering in the Sea of Japan, so they describe this tracked group and migratory route.
U.S. Marine Mammal Protection Act (MMPA) · Depleted · Eastern Pacific stock (Pribilof and Bogoslof Islands)
In the United States, the Eastern Pacific stock, which includes the Pribilof and Bogoslof Islands, is designated as depleted under the Marine Mammal Protection Act (MMPA). The Pribilof population that prompted the designation fell to less than half of its late-1950s level of about 1.8 million seals, leading to its 1988 designation. The California stock is assessed separately and is not depleted under the MMPA. The 2024 assessment lists environmental changes, disease, predation, contaminants, fishery effects, and incidental take among possible factors in the Eastern Pacific stock’s decline or lack of recovery. The cause of the decline has not been identified.