Beluga whales have a small, blunt head with a beak and a rounded melon. Belugas have a dorsal ridge instead of a dorsal fin and a sleek, pure white pigmented body. While the adult beluga whale is pure white the calves are tan and the juveniles are blue to grey. Flippers are short, rounded and wide and the flukes are wide and deeply notched. Beluga whales possess a flexible neck and can swivel their heads right around 90 degrees. Belugas spend between 40 and 60 percent of their time below the surface. Dives can last for 15 minutes and belugas can dive to depths of 800 meters. About 70 percent of dives are over 40 meters deep and 80 percent of dives include prolonged trips to the bottom. Belugas are slow swimmers which take advantage of ocean currents to get around. Usually belugas complete two to three breathing sequences between dives. Belugas can produce whistles and pulsations as well as snaps, creaks and growls. Belugas possess a very efficient echo location system which they use to navigate and to find prey. Belugas may live to be thirty years old.
Belugas are toothed whales with 34 teeth and they consume 50 pounds of food daily. Suction is the main technique used by the beluga to capture bottom-dwelling prey. Beluga use their teeth to capture prey that it swallows without chewing. Being both benthic and pelagic feeders, the belugas have a very catholic diet which includes such fish as capelin, herring smelt and sand lance. From the bottom belugas take crustaceans and polychaetes and from the benthic waters they take squid and octopus. Belugas actually spend relatively little time hunting for food due to their highly efficient hunting strategies and detailed knowledge of their marine habitat. Often they have been known to hunt schools of fish cooperatively in small groups of beluga whales. The transfer of knowledge from mother to calf takes longer than it does for baleen whales as many of it's hunting strategies require cooperation, skill and knowledge of habitat.
Female belugas attain sexual maturity between eight and fourteen years of age while male belugas attain sexual maturity between 16 and 18 years of age. Mating transpires between April and June. Female belugas carry their babies in their wombs for a 12 to 15 month gestation period. Belugas calve from June to September. Nursing last from twenty to thirty months and the female beluga's milk for suckling is 28 percent fat. Calves are about five feet long and weigh 140 pounds. Single births are the norm and twins are very rare. During a dive beluga whales reduce their heart beat from 100 beats a minute to between 12 and 20 beats per minute. Blood flow is diverted from certain tissues and organs towards the brain, heart and lungs, which require a constant oxygen supply. The amount of oxygen dissolved in the blood is 5.5 percent, which is greater than in terrestrial mammals and is similar to levels in Weddel seals. One study found that a female beluga had 16.5 litres of oxygen dissolved in her blood. Belugas produce a rapid sequence of clicks that pass through the melon, which acts as an acoustic lens to focus the sounds into a beam that is projected through the surrounding water. The sounds spread through the water at a speed of 1.6 kilometers per second, four times faster than the speed of sound in the air. These sound waves rebound from objects in the water and return as echoes that are heard and interpreted by the animal. Using it's melon acoustic lens to focus the sound waves into a sound beam the beluga is employing a kind of sonar to interpret it's undersea landscape. This enables the beluga to assess the distance, speed, size, shape and structure of objects from which the beam of sound bounces off.
Belugas are most often found either in pairs or in pods of ten whales. Usually there is one dominant male whale in the pod of ten whales. Belugas are also known to congregate into clans of several dozen to a hundred whales and male belugas are often found in groups of five to ten whales. In summer, the largest herds tend to be comprised of female belugas accompanied by newborn calves and juveniles. Belugas are very energetic and may roll on their sides, swim about in all directions and come out of the water to spyhop or slap their tails. Usually belugas live in estuaries near the coast where coastal waters are stirred up by strong currents. Such estuaries provide good places to find salmon, char, pollack, capelin and herring and good places to give birth and nurse calves.
Between 1868 and 1911 Scottish and American whalers killed more than 20 thousand beluga whales in Lancaster Sound and the Davis Strait. Beluga whales are now hunted only by Inuit hunters who have a negligible impact on populations and there is minimal commercial hunting in Russia. Degradation of water quality around the major estuaries of the St. Lawrence is a big concern and this may be caused by dredging, shipping, industrial activity, climate change and environmental contamination. Such degradations in water quality impact both food supply and habitat quality. Damming of large river and disturbances caused by ships are a major concern. Beluga whale conservation is the main motivation behind the Marine Park of the Saguenay-St. Lawrence and at present there are 1100 beluga whales in the Gulf of St. Lawrence. Belugas are the only cetacean to live year round in the St. Lawrence and they prefer waters with 70 percent free-floating ice. The total population of beluga whales is estimated to be 88 thousand whales living in seven major population groups.