A two-week research expedition in the White Sea to study the physiological and behavioural reactions of beluga whales to the sounds of geological exploration work ended on 5 July.
During the experiment, the scientists recorded their reactions to an audio recording of seismic exploration sounds under different conditions.
“We tried to move the experiment to study the impact of noise on beluga whales that we conduct in laboratory conditions at the Utrish sea station of the Russian Academy of Sciences Institute of Ecology and Evolution to an open sea area, where the animals live in conditions similar to a natural environment, albeit in captivity,” Dmitry Glazov, the head of the expedition, a lead engineer at the Severtsov Institute of Ecology and Evolution and the deputy director of the Beluga, the White Whale programme, said.
Specialists from the institute and geologists from the Centre of Marine Studies, as well as Moscow State University’s White Sea Biological Station, went to the township of Nilmoguba, where two white whales, Varvara and Mikhei, live at the Arctic Circle Dive Centre’s spacious enclosure. Both whales were caught at different times in the Sea of Okhotsk. Trainers from the White Sea Ecological Centre are presently preparing them for work in a dolphinarium.
During the experiment, the researchers sought to identify critical noise intensity values for the animals’ reactions.
“We selected sounds of the intensity that do not deafen the belugas, but at the same time are tangible enough to provoke a response from them,” the expedition head said. The sounds used in the experiment were dozens and even hundreds of times lower than those made during the course of oil and gas exploration work or explosive works.
To study the beluga whales’ behavioural and physiological changes, the scientists observed their movements in the water and their breathing pauses before, during and after the experiment.
“This time, we did not have an opportunity to take a blood test to determine their stress level or check their heartbeat because our new wireless sensors are still undergoing trials at the Utrish station,” he said. A graph was made recording changes in the animals’ breathing in response to seismic exploration sounds.
The researchers plan to continue the experiment.
“To make meaningful conclusions, we first need to gather statistical material with more animals and more experiments in different conditions,” Glazov said.