During the depths of winter, sea ice in the Northern
Hemisphere covers almost six million square miles, or approximately twice the
size of the continental United States. The average maximum ice cover for
February envelopes the region, which is frozen over, with tentacles of ice
extending as far south as Hudson Bay and the Labrador Sea.
700
foot long icebreaker cleaning springtime path to Admiralty Inlet
Flying over this region will show that it is not a pure
unbroken sheet of ice, but rather resembles a pane of broken glass; the ice
flows continuously jostled by wind, currents and tides.
By late September, the end of summer, the ice has melted to
half its size. In the newly exposed waters and throughout the North Atlantic
Ocean, plankton growth is prodigious. Sunlight sets off a chain reaction of
photosynthesis, and pastures of algae and other phytoplankton burst with life.
Some of the richest fishing grounds in the world, such as the Grand Banks off
Newfoundland and the coastal waters of Iceland, flourish in these cold but
fertile seas.
The life-giver of the Arctic, the sun, ignites a string of
events that by the end of summer will have filled the waters with swarms of
tiny plants and animals. They are the first strands in a food web that extends
from algae to whales, polar bears to humans.
Flock
of king and common eiders, diving ducks which winter in Greenland and Labrador
During the dark, winter months, icebound algae make up only
10% of the plant growth in these waters. But they supply almost the entire
food supply until the ice breaks in the spring.
As the sunlight increases, the phytoplankton layer
thickens, and those tiny marine animals called zooplankton rise in the water
to eat and be eaten. Tiny crustaceans called copepods, about the size of a
grain of rice, feed, and then become the primary source of food for the
bowhead whales.
Also joining the feeding frenzy are the arrowworms,
jellyfish, shrimps and winged snails. Ringed seals, cod and seabirds feed on
these tiny animals, except the jellyfish.
But the key link in the long polar chain is the Arctic cod.
In its dual roles as predator and prey, it transfers energy from the lower
level to the higher level of marine animals. The top link of the food chain in
this region belongs to the polar bears and the Inuit Indian people who are
indigenous to this world of ice and cold.
Orange
starfish and sea anemone in clear waters off coast of Baffin Island
Once the ceiling of ice melts or splits apart and direct
sunlight comes streaming in, the water becomes charged with life and energy.
Nudibranches, tiny half inch long mollusks called sea slugs forage among the
kelp for hydroids.
Beneath the ice near the shore of Admiralty Inlet off the
coast of Greenland, hidden gardens of colour and movement reveal tropical
sights such as soft coral growing next to sea urchins. Water temperature is
not necessarily a limiting factor in the growth of some corals. In fact the
icy waters of the Arctic Ocean harbour an extensive growth of corals which
manage to survive.
In the intense, light filled days from May through July,
the Lancaster Sound area, that inlet of arctic water between Baffin Island and
Devon Island comes alive with wildlife, especially along the floe edge where
the ice meets the open sea.
That same plankton rich environment what supports the coral
and starfish, also sustains a food chain that makes possible the spectacular
processions of migrating whales and birds.
Under the water, on the ice, and in the air, creatures
again bring a sense of abundance to one of the world’s harshest abodes. But
no barren wasteland here. Come the springtime season of light and its
life-giving energy, the Arctic thaws into a true land of plenty.
