Polar Ecology - Threats

Threats

There exist many threats to the polar region. One threat is whaling. Whaling started in the 16th century. People hunted whale to sell the meat. By 1925 the number of whales being killed rose from fourteen thousand to forty thousand. The International Whaling Commission tried to stop whaling in the 20th century (Stonehouse, 192). But the commission was unsuccessful.

Over-fishing is another threat to the polar regions. In the Bering Sea there is a lot of fishing due to the high populations of halibut and Alaskan Pollock. Around the 1970s krills began to become a popular fish to catch. The USSR started advertising food with krill in it so they started over-fishing krill. It has been estimated that 40 tonnes of krill per hour were caught during this time (Fogg, 221). In 1982, the Exclusive Economic Zone was established. This said that a certain country can fish 200 nautical miles (370 km) off the shore. The country is now able to control who fishes in their EEZ area. But the EEZ has been unsuccessful.

Another threat is pollution. There are many land and water areas within the polar regions that are contaminated. This can be due to the transport of oil by large ships. Siberia is one example of a place that has had major pollution in its rivers (Nuttall, 529).

Depletion on the ozone layer is one more threat. The ozone layer has been detected above Antarctica. The cause of the depletion of the ozone layer is due to chlorofluorocarbons and other greenhouse gases. The other main reason is due to man made gases that are released into the atmosphere. There are many environmental effects due to this because the gases that are being released five times faster than they are destroyed (Brown, 31).

Global warming is also having effect on the Arctic and Antarctic regions. Global warming is causing the temperature on the earth to increase. In Plan B 2.0 Lester R. Brown talks about how the Arctic is warming twice as fast as the rest of the world (Brown, 70). He goes on to say that the temperature in the Arctic region has increased by 3-4 degrees Celsius within the last half century. And with the increase in temperatures some worry that if the temperature increases this will create the sea level to rise. Scientists believe that if the Greenland ice sheet melts then the sea level could rise by 23 feet (Brown, 71). The melting of this ice sheet or others could have an effect on ocean currents. It could cause lower temperatures in northern North America. Rising of the sea level will also impact coastal areas. One example is in Bangladesh. If there was a 1 meter increase in sea level then millions of people would have to migrate from the coast. Global warming is also affecting Antarctica. Larsen A is an ice sheet on the Antarctic Peninsula. The sheet broke in 1995, and then in 2000 an iceberg that is 4,250 square miles (11,000 km2) broke off the Ross Ice Shelf in Antarctica (Brown, 72). In 2002 Larsen B, which was 5,500 square kilometers, broke off.

Global warming affects plants and animals. For plants, the warmer temperatures induce stress on the plant (Marchand). For animals, there has been a decrease in the amount of polar bears in the Hudson Bay area (Stirling, 294). Since 1981, the polar bear population has been declining. This is because global warming causes the ice to break up faster so the polar bears are going to the coasts when there are poor conditions (Stirling, 294).