Introduction
My last blog post discussed a land animal in the Arctic: the caribou. For this blog post, we will go to the ocean waters of the Arctic region and explain the effects of climate change on beluga whales.
Baleen vs. Toothed Whales
There are two different types of whale species; baleen (Odontocetes) and toothed (Mysticetes). Baleen, or whalebone whales, have keratin in their mouths in the form of plates instead of teeth. Keratin is the same material that is found in our hair and fingernails. There are small slits in the material that allow the whales to filter small fish. Some baleen whales filter the fish by swimming through a school of fish or gulping large amounts of water. Baleen whales include the right whale, rorquals, humpbacks, and gray whales. The largest animal on the planet, the blue whale, also belongs to this group (U.S. National Park Service, 2015).
Toothed whales are whales that have teeth. They include killer, sperm, and beluga whales, as well as dolphins and porpoises. Not every adult toothed whale has visible teeth present. For example, some beaked whales are a toothed type of whale but their teeth are found under their gums. On the other hand, there are some toothed whales that have up to 300 teeth. Toothed whales consume larger fish, large invertebrates, and marine mammals (U.S. National Park Service, 2015). Toothed whales also have the ability to perform echolocation, while baleen whales do not. They can sense the location of objects around them with pulses of high-frequency sound that they send out.
Appearance
When beluga whales are first born, they are dark gray. As they become older, their skin becomes lighter and turns white when they mature. They do not have a pronounced beak. They have a total of 36 to 40 teeth, with 18 to 20 teeth in their upper and lower jawbones. They are able to easily swim under sheets of floating ice because they do not have a dorsal fin. Instead, they have a tough dorsal ridge. They can move their head back and forth because the vertebrae in their neck are not fused, unlike other whale species. 40 percent of the weight of a beluga whale consists of a thick layer of blubber which stores energy and keeps them warm in the freezing Arctic waters (NOAA Fisheries).
Location
Beluga whales can be found in the Arctic Ocean and surrounding seas of the northern hemisphere. They are found in parts of Russia, Canada, Greenland, and Alaska. There are five distinct sub-populations of beluga whales that live around Alaska. These include the populations of Beaufort Sea, Bristol Bay, Cook Inlet, Eastern Bering Sea, and Eastern Chukchi Sea populations. These sub-population groups of beluga whales are called stocks. Each one is slightly different from the rest. They are geographically and genetically separated. The Cook Inlet stock is the most concerning when it comes to threats from climate change. They are the only population segment that is currently on the endangered species list (NOAA Fisheries, 2022).
Behavior
Beluga whales are very social creatures. They can form groups up to several hundred whales when they migrate. They are given the name “canaries of the sea” because of the variety of sounds they are able to make. These include whistles, squeals, moos, chirps, and clicks (NOAA Fisheries, 2022). They use these sounds to communicate with each other, navigate, and hunt. Their communication abilities are becoming affected by climate change.
Climate Change
Each year, there are about 57,000 beluga whales that migrate south to the Hudson Bay in Canada for the summer (WWF Canada, 2015). Beluga whales are being affected by the loss of Arctic sea ice due to climate change like many other Arctic species. As sea ice continues to decrease earlier in the Hudson Bay region, there is the possibility of more ship traffic that will cause a greater risk for an oil spill in the bay where many beluga whales are. Even though this is not their main home, it is where they spend much of their year and return to each year.
There are also major changes happening in the ecosystem of the Hudson Bay. There have been decreases in fish such as Arctic cod that are dependent on sea ice. This is beginning to affect the food chain in this region, affecting many whale species, including the beluga whale. A warming Hudson Bay also means that more orca whales than normal are present. In the Hudson Bay, beluga whales are the main prey of orca whales (WWF Canada, 2015).
Communication is very important to beluga whales and it is becoming affected by climate change. Under the Arctic Ocean, it is very quiet, but it is becoming increasingly loud when there are storms, ice breakups, or glacier collapses.
There is also increased noises due to the shipping industry. Because climate change is causing sea ice to melt earlier in the spring and freeze later in the fall, there is a longer time period of completely open waters. This causes a greater opportunity for more ships and human activity in this area. The increased noise is affecting the beluga whales’ ability to communicate and echolocate. Underwater sounds from boats were found to be in the same frequency range as the beluga whale whistle for communication. (Halliday, 2020). They can often get confused and mistake their sounds with ship sounds. This could throw off important communication between the whales, navigation, migration, and hunting. There is also a possibility that beluga whales will be hit by ships due to increased traffic. Their prey can also react to increased ships and flee, making it difficult for them to get food.
Works Cited
“Toothed vs Baleen Whales.” National Parks Service, U.S. Department of the Interior, 28 Feb. 2015, https://www.nps.gov/redw/learn/nature/toothed-vs-baleen-whales.htm.
Fisheries, NOAA. “Beluga Whale.” NOAA, 20 Apr. 2022, https://www.fisheries.noaa.gov/species/beluga-whale.
Halliday, William. “Beluga Whale Could Be Silenced by an Increasingly Noisy Arctic.” The Maritime Executive, 20 Dec. 2020, https://www.maritime-executive.com/editorials/beluga-whale-could-be-silenced-by-an-increasingly-noisy-arctic.
“Arctic Beluga Whales Facing Multiple Challenges Brought on by Climate Change.” WWF.CA, 6 Apr. 2020, https://wwf.ca/stories/arctic-beluga-whales-facing-multiple-challenges-brought-on-by-climate-change/.
Images
“11 Arctic Species Affected by Climate Change.” WWF, https://www.wwf.org.uk/updates/11-arctic-species-affected-climate-change.
Fisheries, NOAA. “Beluga Whale.” NOAA, 20 Apr. 2022, https://www.fisheries.noaa.gov/species/beluga-whale.
Additional Links
Click to access fact_sheet_red_list_beluga_v2.pdf
https://seaworld.org/animals/all-about/beluga-whales/conservation/
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