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Arctic Wildlife - Section Under Construction
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 At
first glance, the Arctic landscape appears desolate and lifeless.
With vegetation generally limited to a few inches in height, and
often sparsely distributed, the term "barren grounds"
would seem highly appropriate. Yet there is a surprising richness
in this vegetation; trees are there, even though they cling close
to the soil rather than reaching upwards, and lichens, mosses, grasses
and even flowering plants, though quite tiny, cover the ground where
they can find conditions even slightly favorable for them. Arctic
plant life has succeeded in overcoming the extremely harsh conditions
imposed upon it: the shallow, often sterile soil, the abrasively
high winds, the low soil temperatures, the frequent freeze-thaw
fluctuations - all these factors have developed plants that cannot
fail to capture our admiration and respect for their adaptions to
such marginal conditions.
Arctic seas, partially frozen so much of the time, would also seem
to be too inhospitable for large concentrations of life. Yet, paradoxically,
both Arctic and Antarctic waters teem with marine life on a prodigious
scale that vastly outproduces more benign tropical seas. It is a
physical law that the lower the temperature of the ocean water,
the greater its capacity for dissolved gases like oxygen and carbon
dioxide. Nutrients such as silicates, nitrates, and phosphates borne
by riverine runoff from the surrounding landmasses combine in the
photosynthesis process with oxygen to form diatoms and other single-celled
plant life, which is the flora at the base of the marine food chain.
These organisms propagate at an incredibly rapid rate in the late
summer.
One has only to watch the overturning ice floes as the ship pushes
through the pack ice to realize the amazing fertility of these waters;
the underside of each floe is stained brownish-yellow by the myriads
of microscopic diatoms and other algae that constitute the rich
pastures of the Arctic seas. These in turn feed zooplankton, small
marine creatures of many kinds, including shrimplike krill and squid.
In the Arctic Ocean where cold and warm water masses intermingle,
we find some of the world's best fishing grounds. Of 100 different
fish species, the cod and herring are among the most important.
They are in the process of extending their range northward due to
a warming of the water by 1.3°C in the early part of this century.
Thus, both land and sea forms have adapted to sustain themselves
in the Arctic on the available plant life, either directly or via
the food chains. Insects, land and sea birds, fishes, aquatic invertebrates,
and land and marine mammals often occur in vast numbers of individuals.
But because the environment is relatively young (animals have had
only about 10,000 years to colonize great areas and to adapt to
totally new conditions), and because there is a limited selection
of habitats, the numbers of species is limited.
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