arctic sea ice and the food web page 1 teacher zone nature.ca/education see the associated lesson...

Arctic Sea Ice and the Food Web

Teacher Zonenature.ca/education

See the associated lesson plan athttp://nature.ca/education/cls/lp/lpasi_e.cfm


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


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.

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

of photosynthesis.

Diatoms (Trigonium arcticum) viewedthrough a microscope.Kathy Conlan © Canadian Museum of Nature


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

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


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

slow-moving prey, such as sea

cucumbers, sponges, radiolarians,

nematodes and other animals that live on

the ocean floor.

Isopod (Arcturus baffini).Kathy Conlan © Canadian Museum of Nature

Page 5


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

Page 7


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

Page 8


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

Page 9


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

Page 10


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

Page 11


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

own shell.

Sea star (Crossaster papposus).Kathy Conlan © Canadian Museum of Nature

Page 12


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

between small amphipods and higher

vertebrates.

Arctic Cod (Boreogadus saida).Kathy Conlan © Canadian Museum of Nature

Page 13


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

Page 14


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

Arctic Cod.

Ringed seal (Pusa hispida).©iStockphoto.com/Zvozdochka

Page 15


Beluga

• Belugas are commonly found in ice-

covered 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

Page 16


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

Page 17



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.

Page 18


Arctic Sea ice.Stewart MacDonald @ Canadian Museum of Nature

arctic sea ice and the food web page 1 teacher zone nature.ca/education see the associated lesson...

Documents

food web sea ice

teacher zone nature

underside of arctic

seaice core

sea ice core

caeducation slide

core sample of arctic

sea floor