|
Polar
bear
Polar bears rely on sea ice as their main mode of migration,
riding floes long distances
over the water. Sea ice is their hunting platform; they snare
their prey, mainly ringed seals, when they surface to breathe
at holes in the ice. In a future with less ice, polar bears
will face hunting difficulties, which means longer periods
of fasting and lower birth rates. Polar bears are the largest
land predators on earth. Since they sit atop the Arctic food
chain, any disturbance elsewhere in the
ecosystem can have disastrous consequences for polar bear
survival.
 Bowhead
Whale
Bowhead whales live their entire lives in the frigid waters
near pack ice. Their
physiques are uniquely matched to their habitat. They have
blubber up to two feet thick that insulates them from the
cold and provides food storage during times of fasting. Their
heavy, powerful heads can ram through up to two feet of sea
ice so they can breathe. Bowheads are baleen whales, which
means they scoop seawater into their mouths and filter out
their prey, mainly zooplankton. Much of their feeding takes
place under the ice. Bowheads also retreat under the ice when
they are threatened.
 Walrus
Walruses follow the pack
ice. They haul out onto the ice to rest while diving for
food and they ride floes
while migrating. Their main food source is clams and other
invertebrates that they root out from the shallow sea floor.
As walruses grub about, they release sediment from the sea
bottom into the water column, which helps other members of
the bottom community. It's all part of the nutrient cycle
that originates with the ice algae - without the algae at
the base of the food web, walrus prey would start to vanish.
 Ringed
Seal
Ringed seals live on the ice most of the year - it's where
they rest, molt and birth and nurse their pups. Ringed seals
eat marine creatures that live under the ice, such as arctic
cod and crustaceans. Since they're mammals, the seals need
access to air to breathe. They create breathing holes in the
ice, sometimes over six feet deep, which they maintain with
their tough claws. It's around these breathing holes that
polar bears like to congregate and wait to catch their next
meal. Ringed seals are an important prey animal in the arctic
ecosystem
 Ivory
Gull
Ivory gulls are the only gulls that predominantly live on
sea ice. They are
scavengers whose fortunes are closely tied to those of the
hunters of the arctic. The ivory gull diet consists mainly
of what's leftover after polar bears are done with a kill,
as well as carcasses of other fish and marine mammals. These
birds will sit on the water along the sea ice edge when they
are feeding on plankton, but they prefer to sit on the ice.
They are very sensitive to any kind of disturbance and are
quick to abandon a nest, if a low-flying plane passes by,
for instance. No one knows how the effects of climate change
in their remote habitat will affect ivory gulls.
 Arctic
Cod
These fish hide from predators in gaps in the ice, and the
ice provides a relatively safe nursery for baby arctic cod.
The sea ice also provides sustenance for arctic cod, because
they feed on the plankton that live along the bottom of the
ice. Arctic cod are the most important link in the food chain
between the tiny creatures under the ice that they eat, and
the other fish, birds, seals and whales that, in turn, eat
them. Arctic cod rarely venture far below the surface to feed;
it is unclear how they would adapt to a world with less ice.
Learn
more about the arctic environment in which these animals live.
---------------
3 pages: | 1 | 2 | 3
|
|
