Global Systems & Governance - Threats to Antarctica Flashcards
Why is whaling and fishing a threat to Antarctica?
The ocean’s nutrient rich waters support an abundance of marine life and are the feeding ground for 80& of the world’s great whales. Whaling began in the 19th century. As the whale population of the North Atlantic became reduced due to massive exploitation, whales turned their attention to the Southern Ocean. Whaling was a highly profitable business with products including: oil, whalebones, meat extract and frozen whale meat
Why did whaling no longer become commercially viable?
By the 1960s, whaling was no longer commercially viable as whale populations had declined by over 90% due to overkilling and many species had become endangered. Whales in the Southern Ocean are currently protected, but there is still an underlying threat from Japan and other pro-whaling nations such as Norway and Iceland.
What are krill?
Krill are tiny shrimp-like crustaceans which swim in massive numbers and are a key part of the entire food chain of the Southern Ocean, virtually everything in the Antarctic region depend on krill – sea birds, penguins, seals, whales and other fish.
Why are krill fished for in such high quantities?
Krill are being caught for processing into feed for farmed fish and as a nutritional supplement in the form of krill oil all over the world. They are an excellent source of protein and krill oil is extremely rich in Omega-3 fatty acids and is used to prevent hypertension, strokes and depression. Cartons of krill oil capsules can cost £40 for 100 in health food retail outlets.
How has east Antarctica & sea ice expansion been affected by climate change?
The temperature of Eastern Antarctica has risen by a much smaller amount unlike the Peninsula, there is no significant loss of ice of any kind.
There are four reasons why climate change may contribute to Antarctic Sea ice expansion:
1) Increasing westerly winds around the Southern Ocean, caused by climate change and ozone depletion are driving the seas northwards.
2) More rain and snow resulting from climate change are layering the Southern Ocean with a cooler, denser layer on top.
3) These storms are also freshening the local water, causing it to become less salty, thus raising the temperature needed for sea ice to form
4) Increased melting of continental land ice creates more floating icebergs which contribute to sea ice formation.
How has the western Antarctic ice sheet & Antarctic peninsula been affected by climate change?
Particularly sensitive to small rises in the annual average temperature and the temperature of Western Antarctica has risen and, as a result, the West Antarctic Ice Sheet has thinned significantly.
The warming has had the following effects on the physical and living environment of western Antarctica:
- Distribution of penguin colonies has changed
- Melting of snow and ice has increased colonisation by plants
- Decline in the abundance of Antarctic krill
- Glaciers and ice shelves fringing the peninsula have retreated; some have collapsed entirely
- There is particular concern about the Thwaites Glacier on the west coast as it is melting more quickly than previously thought.
- The Ronne and Ross ice shelves will not add to sea level change but as they break up it increases the flow rate of glaciers behind them, it is the melting of these glaciers that will cause sea level rise.
Why is ocean acidification a threat to Antarctica?
The decline in pH of ocean water results from an increase in atmospheric carbon dioxide concentrations creating carbonic acid, which makes the ocean slightly less alkaline. This rapid rate of acidification makes adaptation difficult for organisms. Ocean water may actually become corrosive to unprotected shells and exoskeletons of organisms, losing these organisms will disrupt food webs.
Threat of the search for mineral resources
There has never been commercial mining in Antarctica as it is completely banned by the Antarctic Treaty and there are no current or known future plans by any of the Antarctic Treaty nations to reverse this decision. However, the future demand for resources will undoubtedly put pressure on the vast mineral reserves that are in Antarctica.
Why is the Ross Sea one of the most likely sites for mining in the Southern Ocean?
- 500 billion tonnes of oil
- 300-500 billion tonnes of natural gas
- Diamonds, gold and other precious metals as well as freshwater
- ‘Antarctica is a treasure house of resources, waiting to be exploited’
When was the largest oil spill in Antarctica?
1989
What was the largest oil spill in Antarctica?
Bahia Paraiso ran aground, sank off the west coast of the Antarctic Peninsula, 600,000 litres of marine diesel, 30,000 sea birds were killed.
What are the three different forms of tourism in Antarctica?
- Seabourne tourism: usually a cruise departing from Ushuaia in Argentina or Punta Arenas in Chile, with the opportunity to transfer to smaller boats for landing or cruising close to shore
- Airborne tourism: flying from Australia, New Zealand or South America; can involve scenic flights over the continent or in some cases landing.
- Fly-cruises: for those with less time or wanting to avoid a long sea journey, flights land of King George Island from where the visitors take a cruise boat.
What are some rules of tourism in Antarctica?
The International Association of Antarctic Tour Operators (IAATO) work with the members of the Antarctic Treaty for formulate mandatory rules, including:
- No large ships of more than 500 passengers are allowed to visit
- When landing, groups must be divided into boatloads of around 20 people, each group being led by a qualified guide
- Briefing tourists on a code of behaviour when ashore
- Limits on visiting sites – each site may be visited only every 3 to 4 days to minimise impact and allow recovery.
Threat of scientific research
Research bases have been constructed around the Antarctic, which has changed the natural environment and, if not handled properly, may threaten to disrupt it. For example, dogs have been previously used to assist scientific research, however, these dogs were sometimes fed seals and penguins when there was no food available. Dogs have now been permanently removed from the continent, but this is just one example of how scientific research must be sustainably managed, or it threatens the Antarctic.
