Noise pollution messes with beluga whales’ travel plans
Belugas are extremely sensitive to noise. Belugas are social animals that live in Arctic. They use their keen senses of hearing to communicate long distances, find prey and escape predators like killer whales. The Arctic isn’t quiet. As the Arctic heats and the ice melts ship traffic is on a rise ,, suffusing these once tranquil waters with the throbbing sound of propellers.
Scientists have known since the 1980s that beluga whales’ sharp senses can pick up boat noise from up to 80 kilometers away. This noise can be more than a nuisance. It can distract belugas from their feeding, nursing, or resting areas, cause stress, and interfere their ability to hear and perceive important information about their environment, such as how deep the water is and where they are located prey. A new study , by Morgan Martin, a zoologist from the University of Victoria in British Columbia, and the Wildlife Conservation Society Canada, has revealed in unprecedented detail how belugas flee, dive, or rush to escape the distressing noise.
A group of scientists from Fisheries and Oceans Canada was granted permission by the Inuvialuit Game Council for eight male belugas to be tagged with GPS trackers and time depth monitors. These monitors log every second where a beluga is located in the water column. Martin was thrilled to be given the data set. The loggers gave “unbelievably cool and precise tracks” as the whales moved around the eastern Beaufort Sea. She says, “We could see exactly to what depth they were diving and how long they were there.”
Martin and her colleagues modeled the recorded encounters between ships and belugas by comparing the 3D whale tracks with the locations of ships. They also animated each interaction.
The belugas’ common reaction to loud noises was to change their direction. Sometimes, the whale would circle back after the ship passed to continue its journey.
In other situations, a beluga would dive in a sharp V-shaped shape when confronted by a noisy ship. It would descend and ascend quickly, rather than stay submerged like it would when foraging. Sometimes, the whales would swim just below the surface and hightail the ship away from the noise. Although a beluga wouldn’t change its direction if it was already swimming away, the study showed that it would swim faster if a ship was within its range of hearing.
Valeria vergara, a scientist in marine mammal science at the Raincoast Conservation Foundation, said that the study’s findings confirm how sensitive belugas to noise.
Sound, which is the main method many marine animals use to communicate with and understand their environment, is Sound. Vergara states that a loud boat passing can cause belugas to become irritable or their vocalizations to cease. This can lead them to experience chronic stress. Not only that, but swimming an extra 50 kilometers off course to avoid the noise uses up energy that is especially precious in the freezing Arctic.
” “When we talk about noise pollution in really important habitats such as feeding grounds, covering grounds, or nursery areas, then that is a problem,” she said.
“Underwater pollution,” Martin says, “is one the most pervasive forms” of pollution. But, unlike oil spillages, which can last for years, she says that noise pollution is “a form completely, absolutely eradicable, if you just remove its source .”
To help beluga whales, it is important that ships be quieter. She says that policymakers should consider creating marine protected areas and quiet sanctuary in key beluga habitats.
This article was first published in Hakai Magazine ,. It is republished with permission.