When you try to imagine what a happy, calm beluga whale looks like, what images do you conjure up? A smiling white blob, reclining on a chaise lounge with a shrimp cocktail? A zen-like cetacean emerging from a meditation workshop session with a rolled-up mat under its flipper? For Manuel Castellote, a researcher at the Joint Institute for the Atmosphere and Ocean (JISAO), the image is less absurd but more exciting. He pictures a beluga “with a large social group, with calves, in an environment where they don’t have trouble finding food and the only threats they face are natural predation.”
For many of the beluga whales living in our oceans, this kind of existence is rare and hard to come by. Fortuitously, while the COVID-19 pandemic brings the world to a grinding halt, our planet’s more sensitive wildlife, including beluga whales, are being given a welcome reprieve from the anthropogenic (i.e. human-caused) stressors that usually pose a threat to their existence.
Research by Castellote and colleagues at NOAA and JISAO identifies various human-caused noises — such as those produced by ships, jet engines and mechanical drilling — as one of the leading threats to the wellbeing of beluga whales. Castellote, a behavioral ecologist, has been using acoustic techniques to study beluga whales and other cetaceans for more than 20 years. He and his colleagues use recording devices to monitor and measure the noise surrounding beluga habitats in Alaska’s Cook Inlet, along with the sounds the whales make. Listening to audio samples collected by Castellote (included below) in which the gentle sounds of whale song are drowned out by passing ship engines and mining activities, it’s easy to see how the wellbeing of these creatures is challenged when they live alongside large or industrialized communities of humans.
On the upside, the unprecedented reduction in air travel and boat traffic in Alaska’s Cook Inlet area due to COVID-19 and travel restrictions in place since March 2020, is expected to result in quieter, calmer waters for these sonar-sensitive creatures. By comparing acoustic information with concurrent analysis of tissue samples (analyzed for signs of beluga stress indicators, such as hormones, proteins and elements), Castellote and fellow researchers will be able to see what happens when Alaska’s belugas are given some peace and quiet. “Belugas chase fish blind, purely using biosonar, like bats,” explains Castellote. “We’re interested to see if, during these quiet times, belugas might be spending less energy and effort finding and catching prey, or returning to areas they’ve previously abandoned due to the noise and traffic.”
Similar research conducted by UW researchers, including Castellote following the events of September 11th, 2001 showed that quieter waters in Canada’s Bay of Fundy (due to reduced ship traffic) were linked to decreased levels of stress-related hormones found in fecal samples from North Atlantic right whales. This was the first evidence that exposure to low-frequency ship noise may be associated with chronic stress in whales and has implications for other sonar-sensitive creatures living in heavy ship traffic areas, including belugas.
Although the travel restrictions also prevent Castellote and his fellow researchers at NOAA and JISAO from traveling to Cook Inlet to observe the acoustic changes in real-time, they are crossing their fingers and toes that the various recording moorings deployed back in September 2019 will continue to capture any audible changes in the popular beluga habitats. “Are the noise levels really down with the reduced traffic?” asks Castellote. “Will the belugas change their foraging habits? Will they need to work as hard to catch fish?”
With just 279 belugas estimated to remain in Cook Inlet in 2018, the outcomes of this research may help inform conservation and sustainable development in key beluga habitats. Whatever it looks like, the idea of a happy, calm beluga whale is a very comforting one indeed.