Beluga Whales: Canaries of the Sea by Ashton Felts

Beluga whales are sometimes called canaries of the sea because they seem to sing. I, personally, believe that belugas should be protected in part so that the sea will continue to be filled with the beauty of their songs. But their songs are only part of their story.

Beluga whale (Delphinaptherus leucas),with its mouth wide open, White Sea, Russia, Kareliya.

Beluga whale (Delphinaptherus leucas), with it’s mouth wide open, White Sea, Russia, Kareliya.

Delphinapterus leucas

The beluga, or white whale, is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus Delphinapterus. It is adapted to life in the Arctic, so has anatomical and physiological characteristics that differentiate it from other cetaceans. Amongst these are its unmistakable all-white color and the absence of a dorsal fin. It possesses a distinctive protuberance at the front of it’s head which houses an echolocation organ called the ‘melon’, which in this species is large and plastic (deformable).

The Melon

The melon is a mass of adipose tissue found in the forehead of all toothed whales. It focuses and modulates the animal’s vocalizations and acts as a sound lens. It is thus a key organ involved in communication and echolocation. The melon is structurally part of the nasal apparatus (the nose) and comprises most of the mass tissue between the blowhole and the tip of the snout.

A beluga whale's 'melon'.

A beluga whale’s ‘melon’.

Unlike other cetaceans, belugas can move their head up, down and side-to-side because their cervical vertebrae are not fused. This adaptation is believed to help them maneuver and catch prey in silt-laden or ice-covered areas.

The Beluga’s Body

The beluga’s body size is between that of a dolphin’s and a true whale’s, with males growing up to 5.5 m (18 ft) long and weighing up to 1,600 kg (3,500 lb.). This whale has a stocky body; it has the greatest percentage of blubber. It’s sense of hearing is highly developed and it possesses echolocation, which allows it to move about and find blowholes under sheet ice.

The outer anatomy of a beluga whale.

The outer anatomy of a beluga whale.

These whales generally live together in small groups known as pods. Belugas are gregarious and they form groups of up to 10 animals on average, although during the summer months, they can gather in the hundreds or even thousands in estuaries (the tidal mouth of a large river, where the tide meets the stream) and shallow coastal areas. They are slow swimmers, but can dive down to 700 m (2,300 ft) below the surface. They are opportunistic feeders and their locations and the season. They are very social animals and very vocal communicators that employ a diversified language of clicks, whistles, and clangs. Beluga whales can also mimic a variety of sounds.

Location and Diet

Beluga whales are distributed throughout seasonally ice-covered Arctic and sub-Arctic waters. They inhabit waters off the shores of Russia, Greenland, Canada, Norway and the United States (Alaska). Some belugas are migratory within their limited range, while others remain residents of a particular area. They are found close to shore or in the open sea.

Belugas forage for food in the water column and on the seabed. This typically takes place at depths of up to 1,000 feet, but they can dive to at least twice this depth. They mainly eat fish, crustaceans and other deep-sea invertebrates. Belugas use sound to find their prey. They use sound to communicate and navigate by producing a variety of clicks, chirps and whistles.

During the summer months in some areas, they gather in the estuaries of rivers to feed and calve. Calves are born gray or even brown and only fade to white as they become sexually mature around 5 years of age. Young belugas are usually dark gray in color – the gray steadily lightens as they grow up – reaching their permanent color by the age of seven for females and nine for males. Calves nurse for about two years after a 15 month gestation period.

A mother beluga and her calf.

A mother beluga and her calf.

 

What Defenders Are Doing To Help

Since 2006, Defenders has also been part of a coalition of local and national conservation groups, concerned citizens, and scientists that successfully worked to get the Cook Inlet beluga whale listed as endangered in 2007. The coalition continues to monitor any efforts by the State of Alaska in the courts that seek to strip the whale’s protections.

Belugas and all whales are negatively affected by human activity, including increased development, shipping, oil and gas production and transport, indirect and direct adverse effects from commercial fishing gear and operations. Pollution and habitat destruction and alteration. An increasing concern in marine habitats is noise, which can cause damage to a whale’s hearing and damage it’s ability to communicate, navigate and locate prey.

Whales, like the beluga, are at the top of the food chain and have an important role in the overall health of the marine environment. Beluga whales are also culturally important to indigenous communities in the Arctic. Like polar bears, the beluga depends on sea ice for its existence and can be directly impacted by climate change.

 

References

https://www.worldwildlife.org/species/beluga

http://www.defenders.org/beluga-whale/threats