■ Oceanic acidification (from extra dissolved carbon dioxide) and its long-
term effects on the oceanic carbon cycle.
■ Future fishing, both legal and illegal. Fishing for krill could be
particularly significant as krill are at the bottom of many Antarctic food
chains.
■ Invasive species. Organisms that are not native to Antarctica are being
transported there on ships. Some are being released in ship ballast water,
and seeds and spores are becoming attached to boots, clothing, and
equipment. Some of these invasive species are now able to survive in the
Antarctic as a consequence of global warming. Rats, in particular, are a
threat to Antarctica’s ground-nesting birds. These birds are particularly
vulnerable as there were never any ground-based predators prior to the
introduction of these rats. Therefore, the birds have not developed any
defense mechanism behaviors.
■ Tourism, with the pollutants that accompany ships and aircraft, and the
effects of people and infrastructure on wildlife and the environment.
■ Pollution, CFCs, and other ozone depletors are responsible for the ozone
hole that has appeared over Antarctica for over 30 years.
■ Future exploration and exploitation of mineral reserves, oil, and gas. The
current Antarctic Treaty bans all mining and mineral exploitation.SOLUTIONS
– Address the issue of worldwide climate change.
– Place limits on fishing through enforcement and sanctions.
– Create effective mechanisms to prevent the introduction of invasive
species, create monitoring systems for detecting new infestations, and
move rapidly to eradicate newly detected invaders.MARINE
Oceans cover approximately 75% of Earth’s surface and have a salt
concentration of about 3%. Evaporation of seawater is the primary source of
most rainfall. Ocean temperatures affect wind patterns, cloud cover, and surface
temperature. The oceans supply oxygen through photosynthesis by marine algae
and photosynthetic bacteria, and the oceans absorb a significant amount of