Predation from killer whales, polar bears, and humans, as well as ice entrapment, are common causes of premature death of beluga whales.
Killer whales, polar bears, and humans prey on beluga whales, however, neither killer whales nor polar bears are currently a significant threat to beluga populations.
Polar bears will attack belugas in the same way they would attack a seal, which entails lying in wait at breathing holes.
Killer whales come around August. Belugas can usually hear killer whales, so this makes it difficult for killer whales to attack them. Also, the conspicuous fin makes it almost impossible for a killer whale to maneuver in ice.
It is not uncommon for groups of belugas to become trapped in areas that ice over, often restricting them to small holes in the ice for breathing. If the ice does not break up in time for them to escape, the whales face suffocation or starvation.
In an unusual incident in 1984-85, up to 3,000 belugas were trapped in Russia’s Senjavin Strait. Solid ice stretching 12 miles blocked the path to open water and 1,000 belugas died from hunting, hunger, lack of air, and injuries.
Despite relative isolation from humans, human activities are negatively affecting beluga whales. These activities include habitat alteration in estuarine environments as a result of hydroelectric development in rivers. Other long-term threats are competition with fisheries, off-shore oil exploration, vessel traffic, and pollution. Humans used to hunt belugas for their skin and oil, but not much anymore.
Sources: (AMMPA, 2014, 2017; Balsiger, 2003; Caron & Smith, 1990; Finley, Miller, Davis, & Greene, 1990; Katona, Rough, & Richardson, 1993; Leatherwood, Reeves, Perrin, & Evans, 1982; Leatherwood & Reeves, 1983; Lowry, Burns, & Nelson, 1987; Paine, 1995; Seaman, Lowry, & Frost, 1982; Shelden, Rugh, Mahoney, & Dahlheim, 2003; Thomas, Kastelein, & Awbrey, 1990; Williams, 2002)
Image: The Lamb Family