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Sea. Antarctic krill, which congregates in large schools, is the keystone species of the
ecosystem of the Southern Ocean, and is an important food organism for whales,
seals, leopard seals, fur seals, squid, ice-fish, penguins, albatrosses and many other
birds.
F.
The passing of the Antarctic Conservation Act in the U.S. brought
several restrictions to U.S. activity on the continent. The introduction of alien plants
or animals can bring a criminal penalty, as the extraction of any indigenous species.
The overfishing of krill, which plays a large role in the Antarctic ecosystem, led
officials to enact regulations on fishing. The Conservation for the Conversation of
Antarctic Marine Living Resources (CCAMLR), a treaty that came into force in
1980, requires that regulations managing all Southern Ocean fisheries consider
potential effects on the entire Antarctic ecosystem. Despite these new acts,
unregulated and illegal fishing, particularly of Patagonian toothfish, remains a serious
problem. The illegal fishing of toothfish has been increasing, with estimates of
32,000 tons in 2000.
G.
Most of Antarctica’s icy mass has so far proven largely impervious to
climate change, being situated on solid rock; its deep interior is actually growing in
volume as a result of increased precipitation. The Antarctic contribution to sea-level
rise has long been uncertain. A recent report by CPOM suggests that Antarctica has
provided, at most, a negligible component of observed sea-level rise –indeed a survey
of 72% of the Antarctic ice suggest an attributable short-term lowering of global sea
levels by 0.08 mm per year. Conversely, a 10 year comparison of the balance between
glacier decline and snowfall accumulation found that ice loss had increased 75%. In
2006, Antarctica lost a net 200 billion tones of ice.
H.
However, Antarctica’s periphery has been warming up, particularly on
the Antarctic Peninsula and in Pine Island Bay, which together are contributing to a
rise in sea levels. In 2003 the Larsen-B ice shelf collapsed. Between 28 February and
8 March 2008, about 570 square kilometers of ice from the Wilkins Ice Shelf in
Western Antarctica collapsed, putting the remaining 15,000 square kilometers of the
ice shelf at risk. The ice is being held back by a “thread” of ice about 6 km wide.
According to NASA the most significant Antarctic melting in the past 30 years
occurred in 2005, when a mass of ice comparable in size to California briefly melted
and refroze; this may have resulted from temperatures rising to as high as 5°C.
I.
Indeed, changing weather patterns in the coming years due to such
gradual warming of the Earth will affect agricultural-based businesses and
communities that most. Agriculture in New South Wales, Australia had reported that
187,240 proprietors and partners and 311,148 employees in agriculture are on the
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