Even though the water around Antarctica is very cold and often covered with ice, the sea supports a large number of different species from algae to invertebrates to larger vertebrates such as fish, penguins and seals.
Food webs
A food web shows what eats what. It shows how energy flows through the ecosystem. Organisms can be divided into producers, consumers and decomposers within a food web:
- producers - green plants - they make their food using the Sun's energy (photosynthesis)
- consumers - usually animals - they must eat other plants and animals for energy
- decomposers - they break down dead plants and animals for food e.g. bacteria
Producers
Producers in the Antarctic Ocean ecosystem are:
- sea ice algae - which live on the underside of the sea ice but may fall to the sea floor
- phytoplankton - which may be carried under the sea ice by currents from open water regions
- macroalgae - leafy seaweeds and algae that are attached to rocks and corals on the sea floor
- microalgae - microscopic algae that lives on the surface of sea floor sediments
Consumers
The plants (producers) are needed by consumers who feed by grazing or filter feeding. Examples include snails, urchins and corals. These consumers in turn will be eaten by other animals such as sea-stars.
At the top of the food web there are larger animals (consumers) such as fish, penguins, seals and whales.
Decomposers
This group of living things break down dead plants and animals for food, releasing nutrients back into the ecosystem. Bacteria are an example of decomposers in a marine ecosystem.
If some animals die due to melting sea ice, it will affect all animals in the food web.
A simple Antarctic food chain.
An Antarctic food web.
Ready for a quiz? Try the 'Antarctic Food Webs' interactive activity.
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