Geoscience Reference
In-Depth Information
commercial value. The best-known work is on the antifreeze glycoproteins
produced by various species of
fish. Uses could include enhanced preservation
of frozen foods and of tissues during medical operations. There is strong pressure
to
find cold-active enzymes for detergents that would work in cold water, thus saving
considerable energy. At present, the Antarctic community and the Antarctic Treaty
have not come to a consensus on how to address the many moral, commercial
and legal issues surrounding bioprospecting. For example, uncertainty about the
use and ownership of samples inhibits the engagement of industry in some countries
in Antarctic research. However, the importance of bioprospecting from natural
environments may be diminishing as more and more new products are designed
in the laboratory.
Carbon dioxide has risen in the last 200 years to a level 30%higher than at any time in
the last 800 000 years as determined fromAntarctic ice cores. The rate of rise of carbon
dioxide is 50-times faster now than at any time in the ice core record. The change
in relative contribution of the isotope
13
Cto
12
C over the last 200 years also con
rms
that the burning of fossil fuel is the main contributor, thus it is incontrovertible that
the recent rapid rise in carbon dioxide is anthropogenic in origin.
Oceans absorb atmospheric carbon dioxide into the mixed layer, the thin layer
of water at the top of the ocean with nearly uniform temperature, salinity and
dissolved gases in two ways, physical absorption and via the
'
biological pump
'
.
Carbon dioxide slowly enters the deep ocean at the bottom of the mixed layer
particularly in regions near the poles where cold, salty water sinks to the ocean
depths. The oceans presently are responsible for removing 26% of the emissions of
carbon dioxide. The ocean around Antarctica is the largest oceanic sink for carbon
dioxide but it is now becoming less effective because the circum-Antarctic winds
are increasing, by about 15
20% in the last 30 years. As a result there is increased
turbulent mixing in the upper layers that brings more carbon dioxide rich water
from depth to the surface, lowering the partial pressure between the ocean and
the atmosphere hence reducing the
-
flux of carbon dioxide passing into the water.
The biological pump is the process by which carbon dioxide is
xed by
photosynthesis and then consumed by animals and ultimately some is transferred
to the deep ocean in the form of dead organisms, skeletal and faecal material. The
carbon occurs both in organic and inorganic forms where much of it is remineralised
by the benthic community but some is sequestered on the ocean
oor. In order to
predict future carbon dioxide concentrations in the atmosphere, it is necessary to
understand the way that the biological pump varies both geographically and
temporally, as well as the impacts on the pump of changes in temperature, ocean
circulation and ocean chemistry (e.g. acidi
cation due to increased carbon dioxide).
Much quantitative research remains to be done on this topic.
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