The Beaufort Sea is one of the marginal seas of the Arctic Ocean. It is bordering the northern coast of Canada and Alaska. The sea, which is characterized by a rough climate, is frozen for the most part of the year. In the past, only a narrow pass of up to 100 km was open near its shores in August-September, but nowadays, as a result of climate change in the Arctic, the ice-free area in late summer has greatly increased. It is a vital component of the Arctic marine ecosystem, covering an area of approximately 476,000 square kilometers. The Beaufort Sea is characterized by its unique blend of oceanic and sea-ice features, with a mix of shallow continental shelves and deep basins. The Mackenzie River, Canada's longest, flows into the Canadian part of the Beaufort Sea to the west of Tuktoyaktuk, one of the few settlements on the shores of the sea. The Beaufort Sea is home to a diverse range of marine life, including Beluga Whales, Narwhals, and Polar Bears. With an estimated population of 39,000, the eastern part of the sea is an important habitat for Beluga Whales. Still relatively untouched by commercial traffic, the Mackenzie River is an important habitat for seabirds. The sea's productivity is supported by the influx of nutrient-rich waters from the Mackenzie River, which fuels the growth of phytoplankton, the base of the marine food web. The sea's ecosystem is, however, vulnerable to the impacts of climate change, including warming ocean temperatures, sea-ice decline, and increased human activities, such as shipping, oil and natural gas exploration.