To what extent are more recent developments in cold environments sustainable ? Fishing can disrupt food chains. For example krill fishing in the southern ocean is depleting food supplies for whales and penguins. Overfishing of a species can severely deplete its population, sometimes beyond recovery. Overfishing of the patagonian toothfish in the Antarctic is currently a concern. Bottom trawling catches fish by dragging nets along the sea-bed. This disrupts the eco system by reducing light levels thought increasing turbidity and catches other species as well as the target one. Its carried out in the gull of Alaska, the greenland sea and the barents sea. Fishing quotes have been introduced to limit the number of fish caught and prevent overexploitation of the resource. Large cruise ships increase pollution in the areas from the ships and from the tourist. Tourists and tourism developments disrupt wildlife and damage habitats leading to reduced biodiversity.
National parks have been set up to allow tourism whilst protecting the environment e.g. denali national park in Alaska was set up in 1917 and then expanded in 1980 to induce a greater area of land. Cars and private vehicles are banned from the park so visitor’s have to travel in park buses on approved routes. The most vulnerable parts of the park don’t have any roads at all. So the ground is protected from the damaging effects of vehicles. Oil spills can occur during transport of oil from the area. For example in 1989 there was a huge oil spill off the coast of Alaska when the exxon valdez oil tanker crashed. Over 40 million litres of oil spilled into the ocean and over 250 000 birds and fish were killed. Oil spills can occur if the pipelines leak between 1977 and 1994 there were on average 30 to 40 spills a year from the trans-alaska pipeline. Some of these were caused by intentional attacks and forest fires. Oil pipes have automatic shut off valves in order to minimise oil spills if the pipelines are damaged.