Arctic marine food web. Research in the Beaufort Sea suggests that ice algae at the base of the marine food web may have already been profoundly affected by warming over the last few decades. – Arctic Climate Impact Assessment (ACIA)
The Arctic Ocean and parts of Russia, Canada, Greenland, Lapland, Norway, Alaska, and Iceland make up the Arctic region of the North Pole. North of the Arctic Circle at 66°33″N, it is the land of the midnight sun and polar nights. There is a July isotherm at 10°C or 50°F in accordance with the treeline. The huge, ice-covered Arctic is considered an ocean with eight states even though many scientists simply consider these areas the subarctic region. Although there are no trees and the ground is frozen, the Arctic is home to fish, marine mammals, birds, land animals, and humans who have adapted to extreme conditions. Although the Arctic remains a mystery to many, its importance to the Earth’s balance should not be underestimated. As a place sensitive to climatic change and simultaneously in a key position to influence the climate of the rest of the world, the conditions of the Arctic may foretell the fate of the world, which has made the Arctic region the subject of much environmental study.
The magnetic pole changes everyday, so the North Pole is never in one location in reference to the magnetic north pole. These changes are observed by scientists and affect compass readings in this region. The Arctic region is considered to be all areas north of the Arctic Circle at 66°33″N Latitude. Other landmarks are where the winter sea ice ends in the south or where the trees begin to grow on land.
The Arctic is called the land of the midnight sun because when the North Pole faces away from the sun it is night for half of the year and when it faces towards the sun it is day for the rest of the year. The Arctic Ocean is bordered by Canada, Greenland, Russia, and Alaska with the North Pole located in the middle. Due to the ice cover, it is possible to walk on 2-3 m ice flows that float on 4,000 m of water. Temperatures are -30°C in the winter and 0°C in the summer. These extreme conditions provide the perfect location for the study of extremophiles and unusual animals like the musk ox, polar bear, walrus, and many bird species. Scientists have studied the Arctic through expeditions for centuries. More modern research utilizes cruise ships, scientific vessels, ice camps and research facilities rooted permanently in the region. Some scientists are using satellites and long-term unmanned instruments placed in the icy ocean to collect data. Computer models are also used to see what the effects would be if the environment changed.
Nature and Natural Resources
A land with vast natural resources including tourism, oil, gold, metals, and diamonds—the Arctic is valuable in a number of ways. Unfortunately, because everything living is connected, pollutants and toxic metals from industrial countries are transported to the Arctic through various ecological cycles. Many of the natural resources that the animals and people of the Arctic rely on have become contaminated by waste from other places. The greenhouse effect is also changing the Arctic by decreasing permafrost and sea ice, changing precipitation, warming the air, and allowing hazardous UVB radiation to penetrate the ozone. If the Arctic sea melts, it is possible that the sea level will rise and unwanted and severe consequences will occur in coastal countries worldwide. It is unclear whether tourism will benefit the Arctic region or whether it will create additional environmental problems. The Arctic is one of the last wild places on the globe with exotic species, significant biodiversity, and important habitats. It is also one of the most fragile and easily disturbed areas.
Another animal living in the Arctic successfully is the human, with many Native societies and an impressive history. Now populated by people of European descent, the culture of the indigenous people must be preserved to ensure that their carefully developed survival skills will be passed on to future generations. Indigenous people make up about 70% of the population in the mainland areas of the Bering, Beaufort, and Chukchi Seas. In Alaska, there are only three main groups of natives: the Inuits, the Indians, and the Aleuts. About 50,000-70,000 native people inhabit both Russia and Alaska combined. The Canadian Arctic has 50,000 native people making up over half of the population. The main minority categories here are Indian, Inuit and Métis. The protection of the native people is not only important for the preservation of survival skills but also because they are role models for sustainable living.
The Changing Arctic
In the last 30 years or so, the Arctic has experienced warmer spring temperatures in Alaskan regions, warmer winters in Northern European regions, melting sea ice in the center of the Arctic, and the invasion of tundra by wet and shrub lands in Alaska, Canada, and Siberia. When the resources available in the Arctic are in full use, ecosystems and local cultures could soon experience dramatic change with repercussions felt all over the world. A climate impact assessment was released in 2004 modeling some of the changes that may occur in the Arctic if it continues to be affected by waste from other areas and unsustainable development.
Data from 50 years ago is incomplete; therefore, it is difficult to assess how significant recent changes in the Arctic are. Changes also vary among regions as can be observed with Alaska, which is warming, and Canada, which is cooling. Some changes are likely natural; however, there is significant evidence that the greenhouse effect is responsible for much of the climatic variation. Most changes over small periods of time are likely to be natural, while those over long periods of time may be related to human activity. Although there have been reports of large areas of open water in the North Pole, it is more important to focus on the gradual thinning of ice in large areas over a long period of time. The thinning of ice will disrupt the heat balance in the northern hemisphere and could also affect the circulation of ocean waters.
Environmental impact assessment
Due to the relative lack of scientific data, it will be necessary for local people, businesses, politicians, and scientists to work together to provide information about the Arctic to develop an environmental impact assessment. After data is collected, it must be accessible to locals and used effectively to plan the next stages of resource management.
Understanding the influence of the Arctic on the earth’s climate and its natural environment is essential to understanding the future of the global climate and environment and to the future of the Arctic region’s natural resources. Partnerships such as the International Arctic Science Committee (IASC) comprised of scientists, the Arctic Council, the Barents Council, and regional efforts.
The Southern Ocean
The recently designated Southern Ocean envelops the continent of Antarctica and is the fourth largest ocean in the world. Formerly the Southern Ocean was a traditional mariner’s term, but the name was made official by the International Hydrographic Organization in 2000. The Southern Ocean was previously considered by non-mariners to be the location where the Atlantic, Pacific, and Indian Oceans stretched to Antarctica.
The ring of water enveloping the continent of Antarctica is located between 60° S latitude and 360° S longitude. Connected with the Antarctic Circumpolar Current the Southern Ocean includes the Amundsen Sea, Drake Passage, Ross Sea, Bellingshausen Sea, Weddell Sea, and part of the Scotia Sea. The coastline length is 17,968 km and the area is 20,327,000 km². The Antarctic Circumpolar Current, the world’s largest ocean current, moves eastward and divides the Southern Ocean from the other oceans. The Southern Ocean is 30 million years old and was formed when the Drake Passage opened between Antarctica and South America. At the northern point of the Southern Ocean is the Polar Front or Antarctic Convergence separating colder surface waters from warmer surface waters. The Polar Front and the Antarctic Circumpolar Current encircle the continent of Antarctica and travel down to New Zealand, and to the far South Atlantic where they meet up with the westerly winds.
The temperature in the Southern Ocean is anywhere from -2 to 10°C or 28 to 50°F. The difference in temperature between the ice and the ocean often results in intense storms that make their way eastward around Antarctica. The strongest winds on Earth are found from the latitude of 40° S to the Antarctic Circle. The Southern Ocean freezes in the winter all the way to 65° S latitude in the Pacific and 55° S latitude in the Atlantic resulting in subzero ocean surface temperatures. However, in some areas the coastline remains in liquid state due to warmer terrestrial winds. The ocean surrounding Antarctica reaches down 4,000-5,000 m in most areas with a very deep and narrow continental shelf. The lowest point of the Southern Ocean is 7,235 m deep in the South Sandwich trench.
The Antarctic Divergence is where the east to west drift moves waters closest to the continent in a westerly direction. Westerly winds that work most of the year also move water that is further away from the continent in what is called the West-Wind Drift. The Coriolis Effect sends waters off to the left in the Southern Hemisphere. The Antarctic Divergence is created when the East-Wind Drift moves masses towards Antarctica while the West-Wind Drift moves them away.
The Antarctic Convergence is the odd ocean zone encircling the continent where the warmer water from the northern oceans run into the colder water from the Southern Ocean. The cold water flows under the warmer water bringing up nutrients into the Southern Ocean. Animals like zooplankton and phytoplankton using photosynthesis can thrive here and are eaten by krill to form the base layer of the food web.
Environmental issues in the Southern Ocean include concern that the increase of UVB radiation through an ozone hole directly above has reduced the number of phytoplankton, the primary producers in the ocean by 15% and is mutating the DNA of fish. Fishing is extensive and several species are severely exploited such as the Patagonian toothfish. Longlining in the region causes birds to become tangled and drowned. However, seals are regaining numbers after being protected from hunting for the fur trade.
There are several international agreements specifically drawn up for this area and these include the International Whaling Commission, the Convention for the Conservation of Antarctic Seals, and the Convention for the Conservation of Antarctic Marine Living Resources. Additionally, the exploitation and search for minerals is against the law in many nations south of the Polar Front. International agreements have also been made to reduce overfishing of these oceans.
The Ice of Antarctica
The ice sheet covering about 98% of Antarctica formed 25 million years ago and holds about 75% of the Earth’s water, an amount that could raise the sea level by approximately 61 m if melted. During the summer the ice shrinks and Antarctica actually gets smaller. The Transantarctic Mountains separate the continent into West and East Antarctica. The only continent virtually uninhabited by humans, Antarctica is the coldest, windiest, and driest place in the world. In winter, the temperatures range anywhere from -20°C to -30°C on the coast to 4°C to -68°C further inland. Summer temperatures are still at the freezing point and will sometimes make it up to 10°C, a little warmer inland. With temperatures sometimes lower than Mars, the snow in this region never melts. Glaciers and ice sheets cover landscapes, valleys, and mountains and flow towards the slightly warmer sea. Once they arrive at the sea and begin to float freely (in a “birthing process” referred to as calving), they are called icebergs. The largest recorded iceberg was named Iceberg B-15 with an area over 11,000 km², larger than the island of Jamaica.
Research in Antarctica
Due to the lack of human influence, Antarctica is a valuable region for research. Between 1956 and 1957, 12 countries collaborated in the International Geophysical Year to establish research stations, communication, rescue efforts, and weather reporting. In 1959, the Antarctic Treaty was signed with the goal of setting the region aside as a pristine and peaceful area to be freely studied by scientists with the hopes of benefiting all of mankind. This treaty also bans nuclear testing and other military weapons and no country is allowed to claim it for their own. After 30 years, the treaty was re-evaluated and found to still be a good idea. Research stations like the McMurdo Station built on volcanic rock resemble small cities. With 50,000 people from more than 25 countries working on the bases, a clean-up effort had to be initiated to take care of the trash accumulation. Now, any country working in Antarctica is responsible for packing their trash out to where it came from.
The Ecology of Antarctica
There are about 85 different types of crustaceans looking like small shrimp or lobsters located in the ocean under the name “krill”. Ranging in size from a centimeter in length to 14 cm, krill feed on phytoplankton at the surface at night. For such a small creature, krill bear the huge responsibility of making up the bottom level of the food chain for almost all of the animals of the Antarctic. Nutrient containing detritus, also known as marine snow, falls through the ocean water and is a major source of food for animals in the ocean below. The detritus is made up out of parts of dead plants and animals as well as waste and crustacean shells, bound together with mucus produced by many animals in the ocean. Most detritus particles are between 1-2 mm in size, although some can be several meters large. The climate of the planet can be influenced by this carbon sink provided by detritus falling to the sea floor.
In the Antarctic, most detritus consists of algae products and is produced between November and February due to the sunlight availability and nutrients provided by upwelling. During the algal bloom, the amount of detritus produced is at a peak and krill feeding on the algae produce waste that will be eaten by animals below. Over millions of years, this process has resulted in the transport of vast quantities of algal materials to the sediment layer in Antarctica. Sediments deposited over millions of years can be studied by geological oceanographers using sediment cores to understand how populations of organisms change over time. When the change is caused factors like temperature, circulation patterns, or nutrient levels in the ocean environment, it is possible to collect clues from sediment cores. In addition to the study of Earth’s history, scientists are also studying the greenhouse effect, which may melt polar ice. Polar ice melt will cause major climatic changes and can cause problems in the polar ecosystem. Parts of the Western Antarctic ice sheets are being studied carefully as an indicator for global warming effects. If one of these melts, there would be a dramatic increase in the sea level all over the world.
Other animals living in Antarctica include penguins, seals, and whales. Penguins are found wild only in the Southern Hemisphere and there are many species living in Antarctica. The most common seals found in this region are the Weddell seal (named after the explorer, James Weddell), the Ross seal (named after the explorer, James Ross), crabeater, leopard, southern elephant, and the Antarctic fur seals. Southern baleen and toothed whales are also found here.
Poles Apart: The Arctic and Antarctic by Galen Rowell
Two Regimes of the Arctic’s Circulation from Ocean Models of Ice and Contaminants (Marine Pollution Bulletin, 2001 – PDF)
Wikipedia: The Arctic
Wikipedia: Antarctic Ocean
National Geographic: Antarctica