Here is a good article about the threat increased ships and ship accidents in the Antarctica increase the environmental threats to the Antarctic ecosystems. The article talks about environmental groups calling for greater shipping restrictions for the Antarctic region. The main issue is that ships not equipped to be in the Antarctic water conditions are increasingly ending up here, especially as tourist vessels, and resulting in oil spills when they get grounded, hit ice, or sink (like the M/V Explorer did in November 2007). The most interesting thing the article talks about is how the heavy oil used by most ships is even harder to clean up in the cold Antarctic waters than when it oil spills happen in warmer waters. The call for increased regulations include requiring the use of marine gas oil, which causes less damage when oil spills occur and are already in use by British Antarctic Survey vessels.