An advantage of being close to shore in the summer is that rivers are unfrozen and may be entered for purposes of finding food and rearing young. Delphinapterus, a very supple animal, can scull with its tail and thus swim backward. Delphinapterus is known to produce a variety of sounds. Many other animals produce underwater noises, but few such sounds can be heard so readily above water as those of the beluga. That Delphinapterus employs echolocation extensively is also suggested by its huge frontal melon, an organ thought to be used in the directing of sonar signals, and by the fact that this genus lives in regions that lack sunlight for months at a time, and in waters that may be partly covered by ice.
Echolocation presumably is used to avoid obstacles and to search for prey on the bottom.
Schools of as many as 10,000 individuals have been reported, but such aggregations are formed only temporarily for migration or in the presence of abundant food sources. The newborn is about 160 cm long and weighs about 80 kg. Lactation lasts for 20-24 months. Potential longevity is 25-30 years. The beluga has been exploited by the native people of the Arctic since ancient times and has been subject to commercial fishing operations in the twentieth century.