The beluga whale, also known as the white whale or, by the Inuvialuit, "qilalugaq", is an odontocete or toothed whale. Belugas are found throughout the Arctic and are the most common type of whale in the Beaufort Sea. There are seven stocks of beluga whales in Canadian waters and the Beaufort Sea stock is one of the largest. Several studies have been done on the beluga in this area, dating back to the 1970s. Using data from an aerial survey conducted in 1992, the most recent estimate of stock size is 40,000.
Beluga arrive in the southeast Beaufort Sea from the Bering Sea in late May and June and first congregate in Amundsen Gulf. They travel westward along the fast ice edge offshore of the Tuktoyaktuk Peninsula, and as this ice breaks, enter the warm, shallow waters of the Mackenzie Estuary. Beluga aggregate in the Estuary during the month of July, but individual whales also move between the estuary and the offshore, averaging 4 days (range 1-27) in the estuary per visit. Theories as to why beluga congregate in estuaries include a thermal advantage for calves, availability of food, and encouragement of moult and stimulation of new skin growth.
During late July through August, their distribution shifts to mainly offshore, but the extent of the range of the Beaufort Sea beluga stock at this time is less well known. Aerial surveys and satellite tracking studies have confirmed that belugas of this stock use the offshore Beaufort Sea extensively. In August, some individuals also travel to more distant areas including Amundsen Gulf and Viscount Melville Sound. The return fall migration to the Bering Sea wintering areas begins in August and continues into September, and occurs far offshore, seaward of the continental shelf.
About once every 10 years, beluga whales seem to get "trapped" by ice in the Husky Lakes area, according to records dating back to the 1960s. Ice entrapment occurs when belugas, usually bachelor pods, enter the lakes in August presumably to feed on the abundant fish there. In some years, as many as 2000 whales may go into the lakes area in August, although most leave the area before freeze up. Occasionally a few do not leave soon enough and become trapped as the winter ice forms. The largest number of trapped whales that has been observed to date was 125 in 1989.
While in the Mackenzie Estuary, Beaufort Sea belugas have been the subject of a long-established traditional subsistence harvest by the Inuvialuit, the people of the western Canadian Arctic. The harvest occurs primarily in July in the Estuary, and in late July/August, near the communities in Amundsen Gulf. The size of the harvest has declined in recent decades, currently less than 100 animals/year, which is small compared to the size of the stock. The struck/lost ratio is low, less than 5% and primarily males are taken. The harvest is self-regulated by the hunters, according to the Beaufort Sea Beluga Management Plan. A copy of the Management Plan can be found at the Fisheries Joint Management Committee.
The beluga whales landed in the subsistence harvest are measured, sexed and sampled. This program has been getting information on the landed animals since 1980. Adult males harvested from the nearshore Beaufort Sea average 4.3m in length, while females average 3.8m. Belugas live to be 35-40 years old; older individuals have been found in the Eastern Beaufort Sea stock. Newborn calves measure 1.5m in length and weigh 50-80 kg at birth. Growth rates have been determined for this stock and, particularly between 2000-2008, there was a weak but sustained decline.
Given the importance of belugas to the culture and nutrition of the Inuvialuit, maintaining a healthy, stable population is critical to meet co-management objectives and to ensure that the harvest remains sustainable. The numerous studies on the beluga in the Beaufort Sea have provided a solid, long term view of the distribution, size, movements, growth and harvest of these whales. Photo Gallery and Contributors show who has been involved in the various studies through the years.
In response to interest by the oil and gas industry in exploration and future production, along with the need to conserve the healthy beluga population and sustain the regular annual subsistence harvest, the Tarium Niryutait Marine Protected Area (TNMPA) was created, under Canada's Oceans Act, in the Mackenzie River estuary in 2010. The conservation goal of this MPA is to ensure the long term health of Beaufort belugas and their supporting ecosystem. This and future work contributes to the monitoring of the Estuary and ensuring the conservation objectives are met.