Energy and ecological productivity
- Polar ecosystems are simple in structure, but often have long food chains which link both terrestrial and marine ecosystems.
- In terrestrial ecosystems 90 per cent of energy flow is accounted for by plant production, 8 per cent by decomposition and 2 per cent by flow through herbivores and carnivores.
- Productivity studies of the Lancaster Sound ecosystem, Canada, illustrate the dominance of one or two species, in this case Arctic cod, in energy flow.
- Marine ecosystems have variable productivities, depending upon the thickness, and length of time, of the pack-ice cover.
- Population cycles in mammal populations have long been recognized, though there remains considerable debate on their causes.
- The removal of surface vegetation removes an important insulating effect, usually leading to melting of the permafrost.
- Melting of permafrost usually leads to subsidence, flooding and the development of thermokarst terrain.
- Construction techniques involve putting buildings on piles and/or building on thick pads.
- The problem of municipal water, waste and heating systems can be solved by ‘high-tech’ above-ground systems.
- ‘Low-tech’ solutions involve building on thick gravel pads or wooden blocks.
Impacts of oil and gas fields
- The transport of oil and gas in polar regions by tanker and pipeline poses severe problems of environmental impact.
- Major spills of oil in Alaska and Russia are exacerbated by the fact that at 5° C oil degrades ten to twenty-five times more slowly than at 25° C.
- The problems of cleaning up oil spills are compounded by the remoteness of polar regions, and the huge expense of mounting clean-up operations.
- The impacts of oil and gas industries in polar regions cover a wide range of activities – production fields, transportation corridors, seismic trails, materials sites and living camps.
- Oil is transported at high temperatures (about 65° C), whereas natural gas is transported at low temperatures (below 0° C).
- The discovery of DDT in Antarctic penguins is a reminder that polar regions are affected by pollution from the chemicals used in mid-latitudes. • The long food chains and high body-fat contents of Arctic mammals mean that ‘biomagnification’ of pollutants is a very serious matter.
- The four main elements of Arctic pollution are chlorinated organics, heavy metals, radionuclides and acid precipitation.
- The effects of pollutants on marine mammals, land mammals and birds can reach lethal levels.
- Radioactive pollution by radionuclides is of particular concern following the Chernobyl accident of 1986 and the widespread use of nuclear reactors in marine vessels and power stations in the arctic.
Environmental impacts of polar tourism
- Tourism can destroy the wilderness and wildlife aspects of a region which initially attract it.
- Overflights disturb birds and mammals and distribute kerosene residues on ecosystems.
- Cruise tourism disturbs wildlife, pollutes waters and can introduce alien species.
- Land-based tourism has the potential for the greatest damage owing to the permanent facilities for transport and accommodation which it requires.
- Tourism can have potentially harmful results, though good planning can go a long way in mitigating them, and it is possible to overstress the danger.
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