We know that global climate change is affecting many of Earth’s ecosystems in some way, and the arctic is no exception. Kate Stafford discusses the changes in the arctic in her Ted Talk “How human noise affects ocean habitats". For a very long time, the arctic would freeze over in the winter, and Stafford says that “when the ice is frozen solid, and there are no big temperature shifts or current changes, the underwater Arctic has some of the lowest ambient noise levels of the world’s oceans". With the recent increasing changes in all of these factors, the noise level in the arctic is also changing, something that negatively impacts the species that live there.
As greenhouse gas emissions cause the planet to become warmer, increasing amounts of ice melt each year. When looking at images, it actually appears as if the arctic itself has been shrinking for the past three decades. Melting sea ice has a lot of negative effects on the environment. Many arctic species including ice seals, walruses, and polar bears rely on ice for survival, so the risk to them increases as the amount of ice decreases. Additionally, the shrinking of the arctic ice cap is also leading to increased erosion in coastal villages and inconsistent prey availability for a variety of marine birds and mammals.
As I mentioned earlier, the melting ice has also been impacting the underwater noise level in the arctic. When the arctic is covered by ice, the majority of the noise from wind is unable to penetrate the water column because the ice serves as a barrier between the air and the water. This allows the arctic to have very little noise in the winter. However, with less sea ice, there is less of a barrier to block out the noise from the wind, which makes it louder under the water. In addition, the arctic has been seeing more frequent and more intense storms in the past few decades, which further makes it louder for the species that live there. These animals are naturally accustomed to seasonal changes in sound, and the new disturbances that occur during a previously quiet winter disrupt the animals’ natural seasonal behaviors.
The melting sea ice is also changing the ecosystem itself. Since there is less ice during the winter, subarctic species are able to migrate farther north than before. These species can threaten the survival of the natural arctic species in several ways. First, they can compete with them for food. Second, they could introduce diseases or parasites into the arctic. Third, they could predate on the arctic species. Killer whales, which naturally live south of the arctic, have tall dorsal fins that are very inconvenient for swimming under ice. However, now that the ice is melting, killer whales are able to swim farther and farther north, which is bad news for beluga whales, which have evolved without a dorsal fin in order to be adapted to living under sheets of ice. Without ice, which used to be their natural protector, beluga whales are at a greater risk of getting predated upon by killer whales.
There are countless negative impacts that shrinking ice caps have on the species that live in the arctic. As more ice continues to melt, the current problems will only be exacerbated. Doing our part to keep loud vessels out of the arctic is the least that we can do, but to truly restore order to this ecosystem the ice needs to come back. The only way this can happen is if global temperatures and carbon dioxide concentrations return to pre-industrial levels. This seems to be the great challenge of our generation, and the lives of many animals depend on us finding a solution to it.