Specialists hold Okhotsk Sea expedition

Specialists hold Okhotsk Sea expedition

1 August 2011

Under the cooperation of the Beluga White Whale Programme and the project, "Current Status of Amur's Beluga Whale Population (Okhotsk Sea, Russia): Assessment of Sustainability," specialists from the Severtsov Institute of Ecology and Evolution, the Russian Academy of Sciences, conducted field works in the villages of Rybnoye and Rybnovsk in north-west Sakhalin from July 1 through July 29, 2011.


The expedition, held along Sakhalin's coastal waters in the Okhotsk Sea, was conducted from July 1 through July 29, 2011. The objective was to study the population of white whale density in the Okhotsk Sea's Sakhalin Gulf, to take skin samples for genetic analysis, and to continue photo-identification. Scientists also planned to explore the feasibility of catching the mammals to attach satellite tags.


Overall, the expedition was successful, with biopsy samples taken from five living beluga whales, as well as samples taken from the remains of dead belugas found onshore, which will be used for further genetic analysis.


The institute's specialists conducted the expedition with consideration for the region's weather and terrain. The strait's coastlines, the deep sea and strong currents prevent boats from approaching the animals, which tend to dive out of sight to the water depths upon seeing any boat. Given these conditions, in addition to the results of the coastal survey, scientists were led to conclude that capturing beluga whales there would be problematic. Yet, near the village of Rybnovsk, belugas tend to remain in large schools, and will approach static nets, sometimes even swimming inside them. This gives scientists hope that, together with the fishermen, they will be able to catch a few beluga whale species that swim into the nets to attach satellite tags to them.


The summer of 2011 was abnormally warm in the Russian Far East, with massive salmon deaths observed. This may have affected the belugas' health and population, as well as their reproduction rate and fat stores for the winter. During the hot summer, the salmon did not migrate into the Amur River but instead gathered in the cool waters of Sakhalin Gulf. Beluga whales are known to adapt well to frequent changes of temperature between warmer and colder water layers, and they possibly felt comfortable in such conditions, hunting shoals of fish. Satiated belugas are quite socially active and have enough energy to mate and raise calves, while accumulated fat allows for surviving the Arctic winter. Zoologists suggest that the warm summer of 2011 presented favourable conditions for white whales.


Scientists have started analysing the collected findings, and are now developing plans for further research during the next survey season in 2012.