Antarctica

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Antarctica Ecology Effects of Humanity on the
Frozen Continent
Created by Mrs. Melaney Beauvoir Elementary
School Biloxi MS February 2004
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Ecology is the science of understanding the
inter-relationships of organisms and their
environments. We know that the depletion of the
ozone layer is a threat not just to the frozen
continent of Antarctica, but also to the rest of
the world. Global warming is a topic that
scientists have been discussing for decades. We
are beginning to see some of its effects. The
actions of human beings on our planet sometimes
upset the delicate balance of the environments
found on Earth. We can take actions that will
lessen the negative effects. Lets learn how
Antarctica has been affected and about some of
the ways the scientific community is trying to
stop the damage that has begun.
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• There are three main environmental concerns for
  Antarctica
• Krill Harvesting
• Over-Fishing
• Global Warming

Lets look at the negative effects of these three
concerns and at what the scientific community is
trying to do to reduce those effects.
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1. KRILL HARVESTING Penguins, seals, seabirds,
fish, squid and giant whales all eat krill. The
food chain in Antarctica is very
simple Phytoplankton Krill Baleen Whales,
Seals, Birds Penguins, Squid, Seals,
Seabirds Orca, Leopard Seals The largest
animals are the ones who are the most endangered
because they have just one food source krill. If
the number of krill is reduced, humpback, fin and
blue whales would be endangered because that is
all they eat. Scientists think there are several
hundred million tons of krill in Antarctic
waters. But there are some threats that could
reduce its numbers.
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In the late 1970s, fishermen in countries such
as the Soviet Union, Japan, Chile, South Korea
and Poland began to seriously fish for krill. By
1982, the annual catch was more than 500,000
tons. At that time, 93 of the catch was taken by
fishermen from the Soviet Union. Today the annual
catch averages around 400,000 tons. Over half of
the krill that is caught ends up as fish-meal or
animal food it is not eaten by humans. In order
to be eaten by humans, it must be processed
within 3 hours of being caught. If it is not
processed within that time, it begins to break
down chemically, and its body fills with
fluoride. Fluoride is harmful to humans if they
take it in large doses. If krill is processed for
humans, it is usually turned into a paste or the
tail meat is sold in cans.
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OTHER THREATS TO KRILL Phytoplankton is the main
diet of krill. If sea temperatures rise due to
global warming, phytoplankton will not be as
abundant. Higher levels of ultraviolet light
now reach the Antarctic because the ozone layer
is thinner over the continent. Scientists
believe this additional level threatens krill
production.
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2. OVER-FISHING Human activity also threatens
other creatures of the Antarctic seas. Commercial
whaling in the early years of this century led to
a huge decline in the baleen whale population. We
now have the International Whale Sanctuary in the
Southern Ocean which limits the hunting of the
southern whale population. Some species of
Antarctic fish have already been drastically
reduced in number because of over-fishing.
Because so many fish were taken, a large fishery
around South Georgia Island, which used to be
responsible for more than a half million tons of
fish being harvested every year, is no longer in
business. Environmental groups around the
nation have acted to save many fish species from
extinction by limiting the amount of fishing that
can take place.
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3. GLOBAL WARMING Ice ages are periods during
Earths history when large portions of the earth
were covered by icecaps. Scientists think there
have been 10 ice ages during the last one million
years, about 100,000 years apart. Geological
studies show that ice ages develop very slowly,
but disappear rather quickly. Some scientists
think the world is due for another ice age, but
because of global warming, it may not occur.
Global warming is caused by a build-up of carbon
dioxide. It is easier to see the harmful
effects of global warming by studying the north
and south pole regions. Even a small rise in
temperatures will reduce the amount of frozen
water. Scientists are studying Antarctica so they
can have a better understanding of the effects of
humans on the planet and so they can predict if
changes are going to occur.
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• EFFECTS OF GLOBAL WARMING
• If all the ice in Antarctica melted, it would
  raise the level of the oceans by over 200 feet
  (60 meters).
• This will not happen in the near future.
• Scientists do think that sea levels will decrease
  over the next few decades by about 2 mm per year
  because an increase in the amount of water vapor
  in the air (caused by higher air temperatures)
  will make it snow more on Antarctica.
• Higher global temperatures will make icecap flow
  rates increase, and
• more icebergs will be created, which will
• raise the sea level by 3 feet over the next 100
  years.
• A rise of 3 feet seems small, but it means more
  than 100 million people who live in low coastal
  areas around the world would have to move inland.
• A rise in sea level would also raise winter
  temperatures which would increase rainfall and
  flooding.
• Agriculture and natural ecosystems would each be
  negatively affected.

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OZONE DEPLETION The third threat to Antarctica's
ecology is a loss of ozone in the atmosphere.
Ozone is located in the stratosphere, which is a
layer of the Earths atmosphere. The atmosphere
is a very fragile protective layer that covers
the Earth. In 1985, scientists discovered that
more than half the ozone was being lost from the
stratosphere over Antarctica each spring. This
occurs when the sun returns to shine on the polar
ice cap. Scientists found that the depletion is
caused by chemicals that are created in
factories. The chemicals that cause the most
damage are called chlorofluorocarbons (CFCs).
These CFCs are used in solvents, refrigerants,
and to propel contents of spray cans (like spray
paint). When these products are used, they
release chlorine into the air. Chlorine destroys
ozone molecules. We need ozone to protect us
from the ultraviolet (UV) rays from the sun.
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UV radiation causes serious health problems in
humans and also affects plant and animal life.
Humans can develop skin cancers. Plants are not
able to fight off pests and certain diseases.
Phytoplankton growth is reduced, which affects
the marine food chain. Some nations have made
laws to eliminate CFCs. For example, they are
illegal in the United States. However, the
thinning of the ozone has not stopped. By the end
of September 1995, the ozone hole covered over 4
million square miles, an area the size of Europe.
Scientists are concerned and will continue to
study global warming.
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Antarctica seems like it is at the end of the
world, but what happens there serves as a warning
to what can happen throughout the Earths
environments. We must make sure we protect this
beautiful frozen continent by reducing the amount
of krill harvesting, fishing, and pollution of
our atmosphere.
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Information for this presentation was taken
from www.doc.ic.ac.uk/kpt/terraquest/va/ecology
/ecology.html