More work is needed to help beluga whales adapt to climate change though populations in the Delta are holding strong, according to an overview of research summarized by the Aurora Research Institute (ARI.)
Sponsored in part by ArcticNET, the March 30 presentation featured speakers from the Department of Fisheries and Oceans, the University of Manitoba and the Joint Secretariat for the Inuvialuit Settlement Region.
Noting the ISR hosts the longest running Beluga whales research program in the world, Dr. Lisa Loseto of the Department of Fisheries and Oceans went over the work currently underway in the Delta.
Belugas are a “sentinel” species, meaning their overall health is used to track ecological shifts in their range. If the whales experience a significant change in their well-being, it could signal a larger ecological problem.
“It’s a means of integrating food webs given its high trophic level status,” said Loseto. “Its habitat can tell us a bit about interactions within the system as we see losses of ice over time.”
Beluga whales are getting smaller
Scientists can track beluga populations thanks to documentation by Inuvialuit hunters keeping notes of the pod they hunt each summer. Loseto said hunters then pass them on to researchers for analysis. Hunters also provide samples of meat and bone for scientists to analyze at the cellular level.
One canary in the coal mine is the size of Belugas. An analysis of adults from 1993 to 2008 by Lois Harwood found a decline in size among individuals.
“We see whales are getting smaller,” said Loseto. “So this raises a lot of questions about how do we measure beluga health through condition?”
Looking at the thickness of blubber in whale kills, scientists can compare how much weight they’re putting on. As it turns out, it fluctuates each year.
Scientists also document dietary shifts. Loseto said in 2014 most belugas caught by hunters ate sand lances — a small fish that burrows in the ground. Normally the whales subsist on Arctic cod. Loseto added trawlers found that year to be a particularly bad year for cod, which corresponded to low levels of blubber observed in whales. 2014 was also a year of abnormally high phytoplankton in the Arctic. It also was the year of the “blob”, where unusually warm surface waters flowed north towards the Arctic.
Similar but not identical conditions were prevalent in 2019 as well, with Beluga populations noting similar stressors. Further research will help to understand how factors such as ice cover and shipping lanes affect the whales health, said Loseto.
Taking a deep dive into data
Twenty-one distinct populations of belugas live across the Arctic circle, each with unique diving habits and physiology. Estimates put the global population at just over 200,000. Loseto focused on the whales in the Beaufort Sea, which summer just off the coast of Tuktoyaktuk. Scientists estimate these whales to be 40,000 strong, which signifies a healthy population. They are also among the most well-traveled of Belugas, spending their time between the Beaufort and Bering Seas.
Two of Loseto’s PhD students, Enooyaq Sudlovenick and Luke Storrie, also presented their research in their own work. Documenting mercury found in beluga skin, Sudlovenick noted concentrations increased from 1982 to 2002, but decreased from 2002 to 2012. Beluga in the Beaufort Sea higher concentrations of mercury compared to whales in Hudson’s Bay, research shows.
A number of factors are at play, including size differences in beluga populations, local mercury concentrations and the animals’ age. Sudlovenick added more research will help scientists narrow down an exact cause.
Monitoring the frequency and location of beluga dives, Storrie noted the whales migrate south in the winter. Researchers classified 90,211 dives from 2018 into eight behavior types. Storrie added the belugas made shorter, more frequent dives in the winter, spending more time at the bottom.
Storrie also found the whales make deeper, more frequent dives when the sun is out. This could have implications for when human activity is conducted in beluga territory. Storrie said he hopes to map out the beluga’s foraging range so boat traffic can avoid disrupting it.
Modern science, traditional knowledge
Traditional Inuvialuit knowledge is helping improve modern whale tagging techniques. Wildlife biologist Shannon McPhee said a pilot project using harpoons to tag beluga is showing great promise.
Current methods require scientists to capture and surgically attach a tracking device onto the animal’s back, which is obviously traumatic. These methods are also expensive and dated, over 30 years old and requiring large crews and logistics to pull off.
By using a harpoon from a boat to tag a beluga, scientists reduce the impact of their research on the whales. Developed after two years of consultation with the Inuvialuit Game Council, the new program was field tested in 2018.
Initial tests found the tags needed some modifications to stay lodged inside the whales, which Inuvialuit hunters quickly solved by adapting old speartip designs to the devices. Further work between stakeholders led to improvements in the design.
“Beluga skin is arranged into vertical rods,” said McPhee. “This led to the design that uses an applicator to initially puncture the skin and deliver the anchor through the skin and blubber but leaves no sharp edges inside the animal.”
The second round of tests exceeded expectations, said McPhee, with tags recording data for up to six weeks. The quality of data was also as good as the back mounted method.
While still not able to collect data as long as the historical method, which can collect data for up to six months, McPhee noted the new method provided a less invasive way to gather short-term data.
Teamwork over long distances
Chukita Gruben closed off the afternoon by discussing how hunters deployed data collection units on behalf of scientists over the summer.
“Three ARI technicians put together moorings for hydrophones and a soundtrack,” said Gruben. “They were deployed in June by the Inuvik Hunters and Trappers Community near Shingle Point, Shallow Bay and Hendrickson Island.”
Gruben said getting hands-on experience not only helps scientists continue their work, but also exposes new generations to the sciences.
“I feel like it’s not really a job because it’s something you very very much enjoy doing.”