From the satellite perspective, the North and South Poles look quite similar: white caps of snow and ice, tens of millions of square kilometres in size. But that is really all that can said about the supposed similarity, because while at the South Pole, Antarctica, a vast land mass is hidden beneath the ice, at the North Pole the ice floats on the smallest ocean in the world. It is located entirely above the Arctic Circle. The Arctic Ocean, also called the Northern Ocean or for short simply the Arctic is – depending on where the frontiers are drawn – only 12 to 14 million square kilometres in size. With an average depth of 1,120 m, it is a relatively shallow sea. Only the three great deep-sea plains in the central area of the Arctic with average depths of up to 3,000 meters reach further down. The deepest points have been identified as the Litke Deep (5,449 m) and the Molloy Deep (5,669 m) at the transition of the Arctic Ocean to the Greenland Sea. Since the Arctic Ocean borders the continents of Asia, North America and Europe, it is also often called the "Intercontinental Mediterranean".
The Arctic Ocean is the biggest marginal sea of the Atlantic Ocean, with which it is connected via the narrow Greenland Sea between Greenland and Spitzbergen. Approximately 80% of the inflowing and outflowing water is exchanged via this deep-sea connection. A small portion of the Arctic water also flows southwards via the Labrador Current west of Greenland. The connection to the Pacific Ocean via the narrow and shallow Bering Strait contributes less than 20% to water exchange. Despite these connections the Arctic Ocean is a largely enclosed sea with its own characteristics, to which especially the year-round expansive covering of ice on the water contributes. It reduces heat exchange between the ocean and the atmosphere to a fraction of the values that are normal in the open ocean. This means that evaporation is very low. The Yenisei, Kolyma and other rivers of Siberia, or the Yukon and the Mackenzie River in North America all carry huge amounts of icy freshwater that floats on the surface in a thin layer on the salt-rich, dense and slightly warmer Arctic water. The surface currents follow two major systems. On the Canadian side the water rotates slowly in a clockwise direction but in contrast, off the Eurasian coast, it flows in a wide arc from the Chukchi Sea to the Greenland Sea. Both currents have for thousands of years ensured that the Arctic ice drifts incessantly in a gigantic circular flow through the Arctic.
However, the ice does not only circulate, but also expands and shrinks in the rhythm of the polar year. During the freezing-cold winter the ice crust expands and becomes thicker, and then in late summer its size decreases again. This dynamic still exists today but it is changing visibly. For 35 years, satellites in space have tracked the pulsation of the Arctic Sea ice and almost every year they have registered new negative records. The ice is still there, but during the winter its area grows less and less. And in summer it shrinks at a much greater rate than years ago. On average, the area of winter ice has decreased by nearly 1 million square kilometres since 1981, equivalent to about 7%. In September 2012, 40% of the central Arctic was temporarily ice-free, and the ice disappears earlier in the summer and for a longer time in the year, whereby the evaporation increases. But not only the area of the polar ice is diminished; the ice crust is also thinner. On average, it is today only half as thick as in 1975. And because the ice crust is getting smaller, thinner and lighter, it drifts much faster than a few years ago. The dynamic of many of the processes that are connected to the Arctic ice is changing more and more and increasing in speed, also because the inflowing river water is increasingly warm. A development that worries not only Arctic explorers. Especially since computer models lead to fears that in summer 2070, or perhaps even earlier, the Arctic could be completely ice-free.
The Arctic database is still inadequate
The global warming associated with climate change makes the Arctic ice crust, glaciers and permafrost shrink. It increases evaporation, heats the atmosphere and contributes to more dangerous UVB radiation penetrating the ozone layer. And all of this in a region of our planet that is regarded as particularly sensitive and prone to disturbances. Although we are only at the beginning of this development the first signs are already evident. In the last three decades spring warming in Alaska began earlier, winters in Scandinavia have tended to be warmer, and all around the pole the tundra regions are expanding northwards. Some forecasts are not sufficiently firm and contestable since the database for comparisons barely dates back more than 50 years, but with every year in which this trend perpetuates the last doubts vanish a bit more. If the Arctic ice crust does melt in the coming decades it would alter the heat balance of the northern hemisphere and the rest of the world in a very profound way. Large oceanic currents like the Gulf Stream, which serves as a "heat pump" for Northern and Central Europe and significantly influences our climate, would be weakened and modified in their course. The consequences for man and nature would be dramatic, although by no means every change is predictable right down to the smallest detail.
One thing that researchers are absolutely certain about is that these developments would have a significant impact on living organisms in the Arctic both above and under water. At the beginning of the last century many people were firmly convinced that in the Arctic, where temperatures of minus 50° C sometimes prevail, permanent life was not possible. Today, however, we know that some species have settled even in areas around the North Pole itself. Nearly 70 species of seabirds nest every summer on Arctic rocks and beaches. In Alaska alone, the number of breeding pairs that raise their young in 1600 nesting colonies is estimated at 50 million. And there are also a dozen marine mammals: four species of whale, polar bears, huge walruses and sea-lions. All of these Arctic species are threatened by climate change because they have adapted their lives and biology in a unique way to the extreme and seasonally changing conditions of their habitat. Compared to the data collected so far about terrestrial species, however, it is much more difficult to gather data on the pelagic or demersal creatures. The classic methods of marine biology are only of limited use in the Arctic because freezing cold and the compact ice crust make research trips with ships not only more expensive, but often even impossible. Despite these difficulties, already more than 4,000 species have been detected in the Arctic so far, mainly echinoderms such as sea urchins, sea cucumbers, and brittle stars, but also small crustaceans (amphipods), polychaetes and various bivalves.
However, Arctic researchers are convinced that on closer investigation numerous other species would be added. The more familiar with the structures of the Arctic ecosystems, the more we can identify negative environmental impacts and changes in individual species within the biological communities and processes. In order to improve the database for this area, the project "Arctic Ocean Biodiversity" was launched a few years ago as part of the international "Census of Marine Life", a sort of inventory of all living things in this region, with the aim to close existing gaps and to expose structures. The project also includes the collection of data on Arctic fish fauna, which indeed seems doubly threatened. Many species are suffering not only from climate change and increased temperatures, but with the melting of the ice crust they are also becoming interesting for the fishing sector. Catching them would, however, pose enormous risks to the fish stocks, the ecological consequences of which cannot be estimated at present. Under Arctic conditions, most fish only grow very slowly, due not so much to the low temperatures but rather to the lack of food. Since hardly any sunlight penetrates through the ice in the upper water layers, very few phytoplankton and zooplankton can grow there, especially in the central regions of the Arctic. That is why it is mainly subsistence fishing that is carried out there today by means of which Inuit and other regional populations provide themselves with fish. If the ice melts, all this could change rapidly because the region also contains some very attractive resources that are already used (sustainably!) today at the edge of the Arctic and in the Bering Sea.
Global warming pushing some fish species further north
The Barents Sea is home to two major fish communities which are commercially fished at different times of the year. The main fishing season for cod, haddock and redfish which mainly inhabit the area of slightly warmer currents from Nordkapp to the west coast of Spitzbergen extends approximately from February to September. Capelin (Mallotus villosus) and Arctic cod (Boreogadus saida) which prefer the colder water on the Svalbard Shelf are caught mainly from winter to early spring. Cod has been fished since as long ago as the 12th century on the spawning grounds off the Lofoten Islands but regular fishing activity only began in the open Barents Sea around the year 1920 when the temperature of the North Atlantic reached a maximum in the summer for the first time. Today, these waters are among the world's most productive fishing regions and they provide more than half of the Atlantic cod catch.
As the Arctic ice crust melts the Northern Ocean releases more and more species of fish, some of which could also be used by fisheries. According to current knowledge, nearly 250 fish species live in the region of the actual Arctic, in the larger Arctic region there are between 400 and 700, the details vary in literature. Many of these species do not remain permanently in the icy waters but only migrate there temporarily, usually in the warmer summer months. Their number is increasing constantly because climate change is shifting the northern borders of the distribution areas of many species northwards. This awakens new ambitions as could be seen only recently in the disputes concerning the re-allocation of mackerel quotas in the North Atlantic.
While these "migratory species" in some way benefit from the gradual warming of the Arctic, climate change poses a serious threat to the "real", genuinely Arctic fish fauna. Although their number is relatively low with just 75 species and hardly one of them has greater economic meaning, they play an important role within the Arctic ecosystem. Arctic cod and the rarer Greenland cod (Arctogadus glacialis) provide, for example, the food base of numerous marine mammals and seabirds. The decline of Arctic ice is a disaster for the two types of cryopelagic species because they seek protection from their pursuers in the small hollows and depressions on the underside of the ice. If the ice isn’t there this source of protection is lost so that their stocks could be decimated at an above average rate.
The number of pelagic species in Arctic waters is relatively low. One of the most frequent representatives is the glacial lantern fish Benthosema glaciale, which spends the daylight hours at depths of below 1,000 metres and only rises to the near-surface water layers at night. The majority of the fish species in the Arctic Ocean live on or close to the seabed. More than half of them can be assigned to two taxonomic groups. One is the Cottoidei, which belong to the order of Scorpaeniformes and account for about 30% of the Arctic species spectrum. The other is the Zoarcoidei of the order Perciformes, which account for about one quarter of the fish species in the Arctic region. Especially the anadromous migratory fish in the border areas of the Arctic that can almost without exception be assigned to the group of the salmon family (Salmonoidei) are of economic significance: salmon, trout, char and whitefish (Coregoninae).
Growing controversy over the use of Arctic resources
Compared to the other resources and opportunities that the Arctic region offers to potential users, however, fishing is only of secondary importance. The region is rich in valuable raw materials which industries worldwide strive for: metal ores, gold and diamonds, but especially fossil fuels such as oil and gas. According to the US Geological Survey 14 billion cubic metres of petroleum are believed to exist in the Arctic; that would be about one-tenth of the remaining global reserves. There are also an additional 47 trillion cubic metres of natural gas, which due to the melting of Arctic ice are suddenly accessible as a resource. But even without the Arctic ice, it is still extremely difficult and expensive to explore and extract these treasures from the polar region. The extreme cold and the harsh climate, metre-high waves and the months of darkness in winter make the development of this area a risky and costly adventure. Especially as the development areas are often far away from the coasts outside the 200 mile zones in which the bordering states have exclusive rights to the resources there. This leads to a further problem, because oil, gas and other raw materials have eventually to be transported ashore. Environmental protection requirements are high to avoid endangerment of the fragile ecosystem of the Arctic. Environmentalists and NGOs warn constantly about the risks of seismic tests, exploratory drilling, and the increased air and sea transport. The call for even stronger state control is getting louder, and growing public pressure drives the already immense costs even higher, so that even large oil companies and investors are pulling out for the time being and – at least temporarily – putting their ambitions for the Arctic on hold. The world market prices for oil and natural gas are currently so low that the expensive production in the Arctic would simply not be worth it.
At the end of September 2015 Royal Dutch Shell once again stopped its Arctic drilling 70 miles northwest of Alaska after it temporarily suspended activity already in 2012 and 2013 due to technical problems and other setbacks. But only a few people believe the group will give up its plans completely because it has already invested too much in these future areas. Insiders estimate that more than $ 7 billion have already been invested in the project. Russia is also trying to make greater use of its resources in the border areas of the Arctic. The natural gas reserves on the Yamal Peninsula which are probably Russia’s largest are already being used. In August 2011, the state-owned Rosneft signed an agreement with ExxonMobil on cooperation in the use of the Russian Arctic resources, which includes the development of "ice resistant" oil rigs and other technologies that are suited to use in the Arctic. The exploitation of the Prirazlomnoye field, a huge offshore oil field in the Pechora Sea which upon its completion will comprise up to 40 ice resistant oil platforms, began already in 2012. The fact that under the current political conditions in Russia protests against such projects are quite dangerous was impressed upon the Greenpeace activists on the "Arctic Sunrise" in September 2013. The Russian Coast Guard seized the ship and detained the activists for weeks.
As the Arctic ice recedes, the Northwest Passage through the Arctic north of the United States and Canada as well as the Northeast Passage off Russia also moves into the realm of possibility for shipping. Both routes through the Arctic do not only shorten the distances and travel times but also save fuel and costs. The sea route from the Barents Sea to the Bering Strait through Arctic waters is shorter by two thirds than the passage through the Suez Canal and around southern Asia. Although the route through the Arctic is currently rarely negotiable for longer than eight weeks a year, 1.5 million tonnes of goods are already transported along it. By 2020, the volume is to increase tenfold and by 2030 one quarter of freight traffic between Europe and Asia could according to optimistic forecasts of the Russian government be operated via the Arctic. Economically tempting but ecologically risky, because it also increases the risks of shipping disasters, oil pollution and noise pollution, and invasive plant and animal species could be introduced.
The dispute over the rights to use the Arctic is getting heated because virtually all the bordering states from Alaska (USA) and Canada to Greenland (DK), Iceland, Norway and Russia raise claims to the territory. The political affiliation of parts of the Arctic Ocean is controversial. Russia claims for itself vast areas of the Shelf that protrudes 1,200 km in the direction of the North Pole off the northern coast of Siberia, basing its claims on the Nations Convention on the Law of the Sea (UNCLOS) which explicitly allows states to raise claims on the extended continental shelf.
In the face of the growing threats it is a more than encouraging sign that the countries bordering the Arctic agreed in June 2015 to ban commercial fishing in this area and cooperate more closely for fisheries research. Scientists and environmentalists had long called for a suspension of fishing in the Arctic Ocean until the impact of industrial fishing on the ecosystem has been investigated, a management plan drafted, and an international agreement developed to protect the hitherto unregulated waters. Without the ban on fishing the Arctic ecosystem might have suffered irreversible damages before basic information on the occurrence, structure and migration patterns of fish stocks becomes available.