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Arctic Sea Ice and
the Food Web
See the associated lesson plan at
http://nature.ca/education/cls/lp/lpasi_e.cfm
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Arctic Sea Ice and
the Food Web
Sea ice plays an important role in
the food web of the Arctic marine
ecosystem.
In this presentation, you will
encounter a variety of species that
are part of this ecosystem.
Arctic sea ice in Resolute Bay.
André Martel © Canadian Museum of Nature
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Sea-Ice Core
•
The underside of Arctic sea ice provides
habitat for a community of algae and
associated microscopic life known as
sympagic organisms.
•
They are an important food source for
other marine animals higher up in the
food web.
•
In this image, you can see a colony of
diatoms (a type of algae) on the bottom
of a core sample of Arctic sea ice.
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Diatoms in sea ice core.
Michel Poulin © Canadian Museum of Nature
The Basis of the Food Web
•
The basis of the food web in oceans
depends primarily on microscopic plants
called phytoplankton, which usually live
in the water.
•
In the Arctic, phytoplankton are also found
in and on the sea ice.
•
Phytoplankton use the energy of the sun
to make carbohydrates using the process
Diatoms (Trigonium arcticum) viewed
through a microscope.
Kathy Conlan © Canadian Museum of Nature
of photosynthesis.
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Zooplankton
•
This provides a food supply for a
group of tiny animals known as
zooplankton, which live in close
association with, or even inside, the
sea ice.
•
The zooplankton include various
microscopic animals as well as
small crustaceans such as
amphipods, copepods and krill.
Northern Krill (Meganyctiphanes norvegica).
Uwe Kils © Uwe Kils
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Amphipods
•
Amphipods are small, shrimp-like
crustaceans.
•
Amphipods are eaten by fish such as
Capelin and Arctic Cod, which are very
important in the diet of other fish, marine
mammals and seabirds.
•
Some seabirds, such as the Arctic Tern,
also feed on amphipods, as do young
seals.
Amphipod (Anonyx sp.).
Kathy Conlan © Canadian Museum of Nature
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Isopods
•
Isopods are a very diverse group of
crustaceans. The group includes
sowbugs, which can often be seen in
basements or gardens.
•
The isopods that live in the Arctic Ocean
are mostly carnivorous. They feed on
dead whales, fish and squid.
•
Isopods may also be active predators of
Isopod (Arcturus baffini).
Kathy Conlan © Canadian Museum of Nature
slow-moving prey, such as sea
cucumbers, sponges, radiolarians,
nematodes and other animals that live on
the ocean floor.
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Cockles
•
The cockle is a bivalve (an animal
with a shell made up of two
halves).
•
Bivalves include clams, scallops,
mussels and oysters.
•
Arctic cockles are preyed upon by
fish, walruses, bearded seals and
several duck species.
Cockle (Serripes groenlandicus).
Kathy Conlan © Canadian Museum of Nature
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Nudibranchs
•
Nudibranchs are gastropods. They
are commonly referred to as sea
slugs.
•
A nudibranch is carnivore that lives
on the sea floor, and, depending on
the group, feeds on hydroids,
sponges, anemones, bryozoans and
other organisms.
Nudibranch (Dendronotus frondosus).
Kathy Conlan © Canadian Museum of Nature
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Sea Cucumbers
•
Sea cucumbers are animals in the
phylum Echinodermata.
•
They are generally scavengers. They
use their tube feet to trap food particles,
such as dead and decaying matter, from
the sea floor sediment.
•
Many also use their branchial tree to trap
particles suspended in the water.
Sea cucumber (Cucumaria).
Kathy Conlan © Canadian Museum of Nature
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Sea Anemones
•
Sea anemones are animals in the
phylum Cnidaria.
•
They usually remain attached to
hard surfaces, such as shells or
rocks, but some of them burrow into
the sea floor.
Sea anemone (Hormathia nodosa).
Kathy Conlan © Canadian Museum of Nature
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Sea Urchins
•
Sea urchin are another group of
animals in the phylum Echinodermata.
•
They usually live on hard substrates,
and feed by scraping off algae and
encrusting animals with their five teeth.
•
Their teeth are located in a complex
organ on the underside of their shell
that is called an Aristotle’s lantern.
Sea urchin (Strongylocentrotus pallidus).
Kathy Conlan © Canadian Museum of Nature
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Sea Stars
•
Most sea stars are carnivores whose
favourite food are bivalves.
•
They have a unique feeding method:
they use their tube feet to pry open the
two halves of a bivalve, and then they
insert their stomach inside it!
•
Their stomach then releases enzymes
that slowly digest the animal within its
Sea star (Crossaster papposus).
Kathy Conlan © Canadian Museum of Nature
own shell.
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Arctic Cod
•
Arctic Cod are fish that eat mainly
crustaceans, such as shrimp,
amphipods and copepods.
•
Arctic Cod are eaten by a variety of
other large fish, as well as many
seabirds and most Arctic marine
mammals.
•
They are the link in the food web
Arctic Cod (Boreogadus saida).
between small amphipods and higher
Kathy Conlan © Canadian Museum of Nature
vertebrates.
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Walrus
•
Walruses prefer to eat molluscs
(mainly bivalves such as clams and
mussels), which they suck from the
shells.
•
They also consume many other kinds
of invertebrates including worms,
gastropods, cephalopods,
crustaceans, sea cucumbers and other
soft-bodied animals.
Walrus (Odobenus rosmarus).
Stewart MacDonald © Canadian Museum of Nature
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Ringed Seal
•
Ringed seals are the most abundant
seal species in the Arctic.
•
They use the ice for breeding,
moulting and resting. They rarely, if
ever, move onto land.
•
Ringed seals have a varied diet that
comprises primarily shrimp-like
crustaceans and small fish such as
Ringed seal (Pusa hispida).
©iStockphoto.com/Zvozdochka
Arctic Cod.
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Beluga
•
Belugas are commonly found in icecovered waters. They rely on open
water at ice edges, leads and
polynyas as places to surface for
breathing.
•
They feed on crustaceans and small
fish such as Arctic Cod.
Beluga (Delphinapterus leucas).
Buchan/Shutterstock.com
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Polar Bear
•
The polar bear is dependent on sea
ice for most of its needs, and as a
result, is often regarded as a marine
mammal.
•
A polar bear’s diet consists mainly
of ringed and bearded seals.
•
Polar bears also occasionally feed
on whales and young walruses.
Polar bear (Ursus maritimus).
Stewart MacDonald @ Canadian Museum of Nature
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Arctic Sea Ice and
the Food Web
The Arctic marine ecosystem is
more fragile than more-complex
ecosystems found further south.
If one species is lost, there may
be few or none that can take its
place in the food web.
Arctic Sea ice.
Stewart MacDonald @ Canadian Museum of Nature
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