New data on the number of northern fur seal ( <i>Callorhinus ursinus</i>), Steller sea lion ( <i>Eumetopias jubatus</i>), and spotted seal ( <i>Phoca largha</i>) at Tyuleny Island (Okhotsk Sea)

The latest data on abundance and distribution of northern fur seal ( Callorhinus ursinus ), Steller sea lion ( Eumetopias jubatus ), and spotted seal ( Phoca largha ) at Tyuleny Island (Okhotsk Sea) are presented. The total counted number of fur seals was 115 thousand in June-July of 2013, including 5.0 thousand of bulls, 30.3 thousand of females, and 34.7 thousand of pups (31.5 thousand alive and 3.2 thousand dead). Decreasing of the females and pups number is observed during the last 4 years - they became lesser in 18.0 % or 4.5 % per year. The counted number of Steller sea lions was 1879 adults (including 119 bulls, and 1390 females, 68.5 % of them gave birth) and 890 pups. The reproductive group of Steller sea lion increases its abundance on the island due to numerous immigrants. Abundance of spotted seal was very various seasonally and even daily, its highest counted number was 162 individuals

Analysis of commercial hunting on northern fur seal ( <i>Callorhinus ursinus</i>) at Tyuleny Island

Structure of commercial hunting on northern fur seal at Tyuleny Island is considered including effectiveness of podding, age-sex composition of the podded and captured animals, age structure of culled males, and reasons of culling. In total, the number from 2650 to 5099 of fur seals were podded during the harvest seasons of 1990-2008, 45.80 ± 2.17 % of them were killed and 54.20 ± 2.16 % were released. The bachelors prevailed among the podded animals, as well as in the bachelor rookeries (51.70 ± 2.56 %). The bulls were more numerous in the pod (35.80 ± 2.12 %) in compare with the half-bulls (10.20 ± 0.99 %) and the females (2.00 ± 0.85 %). Among the harvested animals, the bachelors prevailed, as well (93.50 ± 1.06 %), whereas the bulls, females, and half-bulls weren’t numerous (3.83 ± 0.87 %, 2.51 ± 0.67 %, 1.49 ± 0.29 %, respectively); frequency of the bulls and females captures changed from year to year. The most numerous age group of captured seals was the 3-year old animals (52.80 ± 1.60 %). All groups were presented among the culling animals, but the bachelors prevailed. The most common reason for culling was injuring of seals by commercial fishery wastes (scraps of fishing nets, ropes, packaging tapes, etc.): 64.20 ± 6.86 % of the culled animals were injured by the wastes

To morphological description of cardiovascular system in pinnipeds (Pinnipedia)

Morphometric parameters of the heart, the absolute and relative caliber of the aortic arch and the major arterial trunks are determined for northern fur seal Callorhinus ursinus , Steller sea lion Eumetopias jubatus , spotted seal Phoca largha , harbor seal Phoca vitulina stejnegeri , and ribbon seal Histriophoca fasciata . The value of cardiac index, the thickness of ventricular wall, and the relative diameter of arterial trunks correlate well with energy expenditures of the entire body of mammals or their certain organs during the life cycle. The hypothesis is confirmed on seals’ adaptation to asphyxia by pronounced dilatation of the aorta ascending that ensures constant blood pressure and supports perfusion of brain and cardiac tissue

On occurrence of northern fur seals in the Tatar Strait (Japan Sea)

Results of observations on northern fur seals in the Tatar Strait are presented. The mammals were observed from the Nevelskoy Strait in the north to Cape Krilyon in the south