ИСТИНА

The spotted seal (SS) is a common species along the Asian coast and forms several local populations. It has been assumed by some authors that the seals in the Sea of Okhotsk and in the Bering Sea are isolated one from another. We studied SS migration and haul-out patterns using satellite telemetry. A total of 10 SS of various ages and both sexes were captured and tagged at the mouth of Bolshaya River, in the Sea of Okhotsk, Kamchatka, in August-October of 1992, 2011, and 2017. Average tag transmission duration was 133 days, and maximum was 182 days (July 24, 2017 to January 22, 2018). Individuals were recorded near the shores of both coasts of Kamchatka during the feeding period (late summer and early autumn), and widely dispersed across the waters in the second half of autumn. Five seals remained in the Okhotsk Sea and moved into Penzhinsky and Tauisk bays and into the waters northwest of Cape Utkholoksky. The other five seals migrated into the Pacific Ocean: two were registered near eastern and southern coasts of Paramushir Island; three moved along the eastern coast of the Kamchatka Peninsula towards the north (two reached the Kronotsky and Kamchatka bays). All movements occurred close to the shore within the 200 m isobath. No confinement of animals of a specific sex or age to a specific water area was observed. It was previously considered that SS that feed on the western coast of Kamchatka during summer do not leave the Okhotsk Sea. However, five out of ten tagged seals rounded the Kamchatka Peninsula from the south and ended up in the Pacific Ocean, marking the first time such movements have been documented. Comparing the data with movements of tagged SS in the Bering Sea, we discovered that Kamchatka Bay was used by the seals from both the Bering and Okhotsk Seas.