New data on the abundance of the northern fur seal (Callorhinus ursinus), steller sea lion (Eumetopias jubatus), and spotted seal (Phoca largha) on Tyuleniy Island, Sea of Okhotsk

Abstract

The latest data on the abundance and distribution of the northern fur seal (Callorhinus ursinus), steller sea lion (Eumetopias jubatus), and spotted seal (Phoca largha) on Tyuleniy Island (Sea of Okhotsk) are presented. Based on the surveys in June and July of 2013, the total estimated number of northern fur seals is 115000. The direct counts showed 5000 bulls, 30300 females, and 34700 pups (31500 live and 3200 dead). The total decrease in the number of females and pups for the recent 4 years is 18.0% (or 4.5% per year). The counted number of Steller sea lions is 1879 adults, viz., 119 bulls, 1390 females (of which 68.5% were parous), and 370 animals of other categories. A total of 890 pups were recorded. The reproductive group of sea lions is increasing due to immigrants. The largest number of spotted seals is 162 individuals. Its seasonal and daily variations are dynamic.