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Arctic Climate Change

5. How will animals be affected by Arctic warming?

  • 5.1 How will climate change affect the Arctic marine environment?
  • 5.2 What will be the impact on marine fisheries?
  • 5.3 How will climate change affect aquaculture?
  • 5.4 How will animals on land be affected?
  • 5.5 What will be the impacts on freshwater ecosystems?

Animal species’ diversity, ranges, and distribution will change. More...

5.1 How will climate change affect the Arctic marine environment?

Ocean accounts for more than half of the surface area of the Arctic region. Many Arctic life forms rely on the sea’s biological productivity and on the presence of sea ice, two factors that are highly dependant on climatic conditions. More...

Polar Bears depend on sea ice for their survival
Polar Bears depend on sea ice for their survival

5.1.1 Polar bears give birth and hunt on sea ice and they need it to travel from one region to another. Survival of mothers and cubs in the spring depends on the mothers’ hunting success, which, in turn, depends on the stability and extent of sea ice. Less winter sea ice means that female polar bears have to go longer without food, which impacts their fat stores, and, in turn, their reproductive success.

Complete loss of summer sea-ice cover, which may occur in the course of this century, could threaten the survival of polar bears as a species or force them to adopt a land-based summer lifestyle. Living on land would not be without risks due to competition with other predators, possible cross breeding with brown or grizzly bears, and interactions with humans. More...

5.1.2 Certain seal species that rarely come to land, such as the harp seal, spotted seal and the ringed seal, depend on Arctic sea ice. Not only does sea ice provide a home for resting, giving birth and raising pups, it is also a feeding ground for some of them. Ice-dependent seal species are likely to have difficulty adapting to ice-free summers. Other species that currently live farther south, such as the harbour and grey seals, are likely to expand their geographic spread if the Arctic has less ice coverage. More...

5.1.3 Some seabirds such as ivory gulls and little auks are likely to be negatively affected by a decline in sea ice. Ivory gulls nest on rocky cliffs and fly out to the sea ice to fish through cracks in the ice and scavenge on top of the ice. A retreat of sea ice away from the coastal nesting sites would have serious consequences. The number of ivory gulls in Canada has already dropped by 90% over the last 20 years. More...

Walrus rely on sea ice for easier access to food
Walrus rely on sea ice for easier access to food

5.1.4 The ice edge in coastal areas is an important feeding ground for the walrus that use the ice as diving platforms to feed on clams on the sea floor. As the ice edge retreats away from the continental shelves to deeper areas, there will be no clams nearby to feed on. Walrus also travel large distances on floating ice, which allows them to feed over a wide area. More...

5.1.5 Ice algae grow at the porous bottom of sea ice and form the base of the unique marine food web connected to sea ice. The melting of ice can affect the availability of physical habitats for algae, as well as the temperature and salinity of surface waters, potentially disrupting the whole food web. More...

5.1.6 In addition to loss of habitat and feeding grounds, climate change poses other threats to Arctic marine mammals and some seabirds:

  • Increased risk of disease.
  • Increased precipitation, which will carry pollution from the south.
  • Expansion of the geographic spread of species ranges, which will increase competition between them.
  • Increased human activity, which will increasingly affect previously untouched areas.

More...

5.1.7 Many marine communities depend on polar bears, walrus, seals, whales, seabirds, and other marine animals. Changes in the numbers and ranges of Arctic animals and birds may greatly affect northern communities’ way of life. So will changes in ice conditions which are critical to the hunters’ mobility. More...

5.2 What will be the impact on marine fisheries?

Arctic marine fisheries provide an important food source globally, and are a vital part of the region’s economy. In the past climate change has induced major ecosystem shifts in some areas and this could happen again resulting in radical unpredictable changes in species present. More...

5.2.1 An example of a positive impact of climate change is the cod population in West Greenland which thrived between the 1920s and 1960s, a time period when the waters were warmer then they are now. A warming of the climate is thus likely to have a positive effect on the cod population allowing more fishing. An example of a negative impact is the fishing of shrimp in Greenlandic waters which is likely to suffer, both from the predicted changes in climatic conditions and from the growing cod population who feed on shrimp. More...

5.2.2 In the early 1950s, the Norwegian herring stock was the largest in the world, and was important to Norway, Iceland, Russia, and the Faroe Islands. In the 1960s, a sudden and severe cooling of the waters west of the Norwegian Sea where the herrings were feeding, combined with high intensity fishing, contributed to the collapse of the Norwegian Herring Stock. Since the 1970s the return of favorable climatic conditions and international agreements on restricting the capture of herring permitted a gradual recovery of the stock. Such international agreements will be crucial in future as climate change alters fish stocks and their ranges. More...

5.2.3 A climate shift also occurred in the Bering Sea in 1977, bringing about an abrupt warming that favored a number of commercially fished species, such as herring, pollock and cod, and led to record catches of salmon in subsequent years.

In some areas, such as most of the North Atlantic, where only a relatively slight warming is expected, the total effect of climate change on fish stocks is likely to be less strong than the effects of fisheries management, at least for the next few decades. In the Bering Sea, however, the impacts of rapid climate change are already apparent, with a displacement or a decline of cold-water species brought about by the warming of bottom waters. While it seems unlikely that the effects of climate change on fisheries will have long-term social and economic impacts throughout the Arctic, particular people and places may be strongly affected. More...

5.2.4 In the past century, certain fishing towns, such as Paamiut in West Greenland, which concentrated on a single fishery resource, such as cod, have been particularly vulnerable when water temperature changes led to the decline of local fish populations. More...

5.3 How will climate change affect aquaculture?

Aquaculture in the Faroe Islands
Aquaculture in the Faroe Islands

5.3.1 Salmon and trout are the two main aquaculture species farmed in the Arctic. Norway has developed a large industry over the past two decades and is now the world's largest farmed salmon producer.

The speed at which fish grow might be expected to increase in slightly warmer water. Greater water temperature increases, however, may have a negative impact on growth rates and the general health of farmed species. Other negative impacts of warmer waters on aquaculture may include increases in diseases and toxic algal blooms. Relocating aquaculture infrastructure further north to adjust to increasing water temperatures would be costly.

The aquaculture industry depends on huge supplies of wild fish (in the form of fishmeal and oil) in order to feed farmed salmon and trout. These wild fish are caught elsewhere in the world, like anchovies from the South Pacific, and can also be affected by climate change. Many of the species that are fished to make fishmeal are also an important part of the diet of certain wild species that are of high commercial value but that are currently not abundant due to overfishing. Reductions in the production of fishmeal and oil might be needed in order for these stocks to recover. More...

5.3.2 The ocean surrounding the Faroe Islands is an important feeding ground for wild stocks of northern European Atlantic salmon. These islands enjoy particularly good conditions for farming Atlantic salmon and rainbow trout.

Despite early setbacks due to disease and market fluctuations, the Faroe Islands have become an important international player in salmon farming. Many people are employed both in fish farming and in related industries, and aquaculture accounts for 25% of the total income from exported goods. Global warming will increase fish growth rates, provided it does not exceed 5°C (9°F). This positive impact (on fish production) would, however, be offset by some warming-related increases in fish diseases and toxic algae blooms. More...

5.4 How will animals on land be affected?

5.4.1 Arctic animals on land include:

  • small plant-eaters like ground squirrels, hares, lemmings and voles;
  • large plant-eaters like moose, caribou/reindeer and musk ox; and
  • meat-eaters like weasels, wolverines, wolves, foxes, bears and birds of prey.

Climate-induced changes are likely to cause a series of cascading effects involving many species of plants and animals. If grasses, mosses and lichens no longer live in the same areas due to a changing climate, it will have implications for the animals that feed on them, and on the predators or human communities that depend on those animals.

Arctic Fox
Arctic Fox

In snow-covered areas, warming could increase the occurrence of repeated freezing and thawing which could lead to the formation of an ice crust thus preventing animals from eating grasses and mosses and sometimes even killing the plants. Lemmings, musk ox and reindeer/caribou are all affected. Dramatic population crashes resulting from this phenomenon have been reported increasingly frequently over recent decades.

Mild weather and wet snow lead to collapse of spaces between the frozen ground and the snow where lemmings and voles live and forage. Furthermore, when the surface of the snow melts and re-freezes the resulting ice crust reduces the insulating properties of the snow pack that is vital to the survival of these animals. Declines in their populations can in turn lead to declines in animal population that feed on them, such as snowy owls, skuas, weasels and ermine. When lemming populations are low, more generalist predators, such as the Arctic fox, switch to other prey species such as waders and other birds, increasing pressure on those populations. More...

5.4.2 Caribou (in North America) and reindeer (in Eurasia) are of primary importance to people throughout the Arctic both for food and for cultural reasons. The herds depend on the availability of food and good foraging conditions, especially at the time when calves are born.

Climate-induced changes are expected to reduce the area of tundra and thus the feeding area of these herds. It will also increase the occurrence of freeze-thaw cycles and freezing rain that make it harder for caribou and reindeer populations to find food and raise calves. Future climate change could potentially lead to a decline in caribou and reindeer populations, threatening the way of life for some Arctic communities. More...

Peary Carribou

The Porcupine Caribou Herd

The Gwich’in and the Porcupine Caribou Herd

5.5 What will be the impacts on freshwater ecosystems?

Freshwater ecosystems in the Arctic include inland waters such as rivers, lakes, ponds, wetlands and their surroundings. They are home to a variety of animal life including fish, mammals, waterfowls, and fish-eating birds. These ecosystems act as intermediaries between land and ocean ecosystems. More...

5.5.1 Increases in the temperature of inland waters can significantly reduce the geographic spread of some species, such as the Arctic char, that may not be able to adapt to warmer conditions or to compete with invasive species that thrive in warmer waters. More...

5.5.2 The thawing of frozen soil can lead to the drainage of surface waters, eventually eliminating aquatic habitats. The thawing of permafrost can also lead to the collapse of the ground surface, create hollows in which ponds and wetlands can form. The balance of these changes is not known, but as freshwater habitats disappear, re-form, and are modified, major shifts in aquatic habitats are likely. More...

5.5.3 The timing of ice break-up in spring strongly affects supplies of nutrients, sediments, and water that are essential to the health of delta and floodplain ecosystems. Changes in ice cover also affect water temperature, levels of oxygen in the water and the exposure of underwater life forms to ultraviolet rays. In some areas, as a result of later freeze-up and earlier break-up, the ice season is now up to three weeks shorter compared to 100 years ago, and this trend is expected to continue. Evaporation and precipitation are expected to increase and flood patterns are likely to change, as will levels of sediments and nutrients carried by rivers to the Arctic Ocean. More...

5.5.4 Warming and increased precipitation are very likely to increase the amount of persistent organic chemicals and mercury that are deposited on the Arctic. As temperatures rise, snow, ice and permafrost which contain contaminants will melt, leading to the release of these contaminants. The resulting increase in the concentrations of contaminants in rivers and ponds may have harmful effects on aquatic plants and animals and also contaminate sea waters. More...

5.5.5 Species of freshwater fish that live in the southernmost part of the Arctic are expected to move northward, competing for food and habitat with species that live in northern inland waters, such as the Arctic char and Arctic cisco. Invasive species from the South may introduce new parasites and diseases. As water temperatures rise, the areas where cold-water species can lay their eggs will also shift northward and are likely to diminish. Inland fishing in the far north is likely to be seriously affected by such changes as the most vulnerable species are often the only fishable species present. However, in some areas of the Arctic, new arrivals from the south and increased growth of species already present may also bring new fishing opportunities. More...

5.5.6 The geographic spread of aquatic mammals and waterfowl is likely to expand northward as habitats change with warming. Mammal and bird species moving northward could carry new diseases and parasites, and take over habitats and resources currently used by northern species. These northern species may be reproducing less successfully due to temperature-induced habitat changes, while changes affecting breeding grounds and access to food may cause seasonal migrations to take place earlier in spring and later in autumn. More...


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