Antarctica

Antarctica

1. Features

   • Large, largest desert.
   • 98% ice and snow.
   • Coldest continent (-49°C), long winters, means few terrestrial species can survive.
   • Little precipitation, snow mainly falls near the coast.
   • Highest altitude.
   • Upwelling of nutrient rich water around Antarctic convergence, supports rich food web.

2. Importance

   • Ice regulates sea levels by storing water on land, if it melted sea levels would rise.
   • High albedo of ice, reduces heating of the atmosphere.
   • Faeces of krill contain carbon from phytoplankton, falls to seabed, acting as a carbon sink helping to control global climate change.

3. Threats

   • Global climate change
     • Melted ice water acts as a lubricant, causing glaciers to move towards to sea more rapidly. Ice shelves around the coast block seaward movement of glaciers so if the ice shelves break, the glaciers can move to the sea easier, breaking off into icebergs.
     • Krill feed on algae of the underside of ice, a reduction in ice reduces krill populations and all the other species that depend on krill (keystone species.)
   • Ozone depletion
     • Plankton is sensitive to UV and increased UV causes a decline in their populations, affecting the rest of the food web.
   • Tourism
     • Tourism rising rapidly, visiting by ship. Waste disposal, oil spills and wildlife disturbance, disease spreading from humans to animals. Small landing sites, reducing wider impact but increases the effects on the sites. Proposals to limit numbers.
   • Overfishing
     • Harvesting krill threatens species that feed on them. Overfishing of Patagonian tooth fish threatens food supplies of sperm whales and elephant seals. Long-lining for tooth fish kills albatrosses as they get caught on the hooks.
   • Future mineral extraction
     • Deposits of many minerals (coal, oil, iron ore, copper, chromium, platinum.) Pressure to exploit increases as other reserves are depleted.
   • Scientific research
     • Fuel spills, waste disposal and buildings impacts. Research stations environmental impacts reduced by careful management.
     • British Antarctic Survey: environmental impact reduced by storing and removing all wastes (except sewage and food), building secondary compartments on oil tanks in case of leakages, using marine gas oil instead of other fuels as it is less persistent and causes less pollution if spilt, banning dogs as they may spread diseases to wildlife, cleaning up and removing wastes from abandoned bases.

4. Conservation (Antarctic Treaty)

   • Antarctic Treaty signed to prevent disagreements with territorial claim overlaps.
   • Antarctica only used for peaceful purposes, military personnel only present to support research.
   • Scientific research must continue unhindered with free exchange of information and personnel.
   • Nuclear explosions and radioactive waste disposal banned.
   • Commercial exploitation of mineral resources is banned.
   • Conservation of living organisms.
   • Environmental impact of tourism monitored.