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. Stock size is estimated as at least 40,000.

Belugas arrive in the southeast Beaufort Sea from the Bering Sea wintering areas in late May and June, and first aggregate in Amundsen Gulf. As spring progresses to summer, they travel westward following along the fast ice edge offshore of the Tuktoyaktuk Peninsula. When the ice ‘bridge’ offshore of the Estuary breaks, the beluga then immediately enter the warm, shallow and freshened waters of the Mackenzie River estuary. Beluga aggregate in the Estuary for many weeks mainly during the month of July, with individual whales moving between the estuary and the offshore, averaging only 4 days (range 1-27) staying in the Estuary. Theories as to why beluga aggregate in estuaries include a thermal advantage for calves, availability of food, and especially to promote the annual molt under the low saline conditions.

During late July through August, their distribution shifts to mainly offshore. Aerial surveys and satellite tracking studies have confirmed that belugas are widely distributed offshore. Also at this time, some belugas travel to more distant areas, including Amundsen Gulf, Viscount Melville Sound and Coronation Gulf. The return fall migration to the Bering Sea wintering areas begins in August and continues into September, occurring far offshore, seaward of the continental shelf.

About once every decade, beluga whales 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 in October. 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 Indigenous peoples of the western Canadian Arctic.The harvest occurs primarily in July in the Estuary, and in July/August, near the communities in Amundsen Gulf. The size of the harvest has declined in recent decades, currently less than 100 animals/year, 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 most recent (2024) Management Plan can be found at the Fisheries Joint Management Committee website (www.fjmc.ca).

The beluga whales landed in the subsistence harvest are measured, sex is determined, and most are sampled. This program has been obtaining standardized information on the landed animals since 1980. Adult males harvested from the nearshore Beaufort Sea average 4.3 m in length, while females average 3.8 m. Belugas live to be 35-40 years old; although much older individuals have been found in the Eastern Beaufort Sea stock. Newborn calves measure 1.5 m in length and weigh 50-80 kg at birth. Growth rates have been determined for this stock and, particularly between 2000-2007, there was an observed directional decline in males.

Given the importance of belugas to the culture and nutrition of the Inuvialuit, maintaining a healthy, stable population is critical to ensure that the harvest can continue and 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 starting in the early 1970s.

In response to interest by the oil and gas industry in exploration and future production, underscored by 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. Past and future work all contribute to the monitoring of the Estuary and ensuring the conservation objectives are met.