Arctic beluga whales facing multiple challenges brought on by climate change
Every year roughly 57,000 beluga whales migrate to Canada’s Western Hudson Bay for the summer, making this the largest summering concentration of belugas in the world. The belugas gather in this area to feed, give birth to their calves, and nurse in the shallow, warmer, productive waters of the Churchill, Nelson, and Seal River estuaries. The whales then migrate to Foxe Basin and Hudson Strait where they overwinter in the sea ice leads and polynyas.
Currently there are no protections for either the summer or winter habitats of the West Hudson Bay population of beluga, which has been designated a species of Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), and is currently being reviewed for inclusion under the Species at Risk Act (SARA).
As with many Arctic sea ice dependent species, beluga whales are affected by the loss of sea ice caused by climate change. As ice decreases in Hudson Bay, the possibility of a larger volume of ship traffic through the port of Churchill will increase, leading to a greater potential for an oil spill in the region. Such a scenario would be very damaging to the coastal habitats which the belugas instinctively return to each year.
There is also a regime shift underway in ecological community structure of Hudson Bay. Documented decreases in sea ice dependent fish in Hudson Bay such as Arctic cod, along with associated increases in more open water subarctic/north temperate species such as capelin and sandlance have very significant implications for the marine food web that underlies the Hudson Bay ecosystem.
As Hudson Bay continues to warm, local Inuit communities and scientific surveys have also documented an increased presence of killer whales in the area. Collaborative research between scientists and coastal communities have noted that while orca (killer) whales were not known to be present in the region prior to the mid-1900s, there has since been an exponential increase in sightings. While in Hudson Bay, beluga have been documented as the number one prey of killer whales, adding another potential climate change induced threat to the Hudson Bay beluga populations.
WWF-Canada is supporting GPS satellite tagging of beluga whales in Hudson Bay to better understand the movements and micro-habitat usage of beluga whales during their annual migrations. This information will be crucial for assessing proposed shipping routes, as well as oil spill trajectories in Hudson Bay and Hudson Strait. It will also allow conservation experts to study to what extent beluga may be able to adapt to their rapidly changing environment.
While this population of beluga whales is currently abundant and stable, future threats in a variety of forms associated with climate change are imminent. Continued research will be essential to monitor this situation, for the largest population of beluga whales in the world, and to inform the necessary conservation measures.