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Human Impacts on cold environments - Coggle Diagram
Human Impacts on cold environments
Change over time
Indigenous people, like Inuit, lived in cold environments for centuries - adapted to landscape & climate, populations are small --> largely sustainable, minimal environmental damage
recently, exploited on a larger scale - immediate & long-term effects on local areas, more damaging to fragile cold environments than small-scale occupation
Oil extraction
oil spills occur during transport of oil:
1989 huge oil spill off the coast of Alaska when Exxon Valdez oil tanker crashed
40 million litres of oil spilled into the ocean
250,000 birds & fish killed
Oil spills occur if pipelines leak:
1977 to 1994 there were 30-40 spills a year from Trans-Alaska pipeline
some caused by intentional attacks or forest fires
Fishing
Can disrupt food chains
e.g. large-scale krill fishing in the Southern Ocean is depleting food supplies for whales & penguins
krill population declined by 80%
Overfishing can severely deplete a population beyond recovery:
overfishing of Patagonian Toothfish in the Antarctic
the way they were fished meant that 100,000 albatrosses were being killed a year when they got caught on a sinking line, threatening a previously healthy population
Bottom trawling catches fish by dragging nets along the sea-bed:
disrupts ecosystem (reduces light levels by increasing turbidity)
catches species other than the target one
Gulf of Alaska, Greenland Sea, Barents Sea
Mining
can lead to ground and surface water contamination:
by chemicals used during mining
by releasing materials being mined into the environment
e.g. a lead-zinc mine in Maarmorilik, Greenland closed in 1990 but levels of lead & zinc pollution in nearby fjords are still high
produces solid waste & wastewater that must be disposed of
some mines don't have facilities to deal with quantities of waste produced, so waste is released into environment, polluting local area
HEP production
Hydroelectric dams can block normal migratory path of fish:
prevents them reaching spawning grounds, so fish population decreases
fish travel long distances to spawn, so this affects a large area of populations
Hydroelectric dams heat up the water - can endanger fish that are adapted to colder temps
Tourism
large cruise ships increase pollution in area (from ships and trousists)
tourists & tourist developments disrupt wildlife and damage habitats - reduce biodiversity