Antarctic life and ecosystems
Antarctica – a land of extremes
Antarctica is the highest, whitest, driest, coldest and windiest continent on Earth. It’s so cold that creatures often retreat to the sea to warm up. Add 24 hours of darkness during the winter months, and it’s a wonder anything lives there. Yet, Antarctica has thriving ecosystems on land and in the water.
The food web in the Ross Sea
This diagram shows how the food web in the Ross Sea works. The arrows go from prey species (these get eaten) to predators (the hunters).
An ecosystem is an interacting system made up of animals, plants, microorganisms and the physical and chemical environment they live in. Antarctica has marine ecosystems and terrestrial (land-based) ecosystems. Ecosystems rely on food webs – where energy and nutrients are passed from one living thing to another.
New Zealand ecosystem research
Two of the three research themes supported by Antarctica New Zealand involve protection, conservation and management of Antarctic ecosystems. Scientists study large marine creatures like Adélie penguins and Weddell seals, but they are also interested in really small benthic marine organisms.
Knowledge of megafauna like seals is crucial for understanding the ecosystem for its own sake and for understanding climate change. The top predators are like the gauge on the petrol tank.
Dr Regina Eisert
Scientists also research what lives on the land. Antarctica is a polar desert. Terrestrial life is limited to the very small. There are no trees or shrubs, so vegetation is mainly mosses, lichens and algae. Springtails are one of the largest living terrestrial organisms – however, these invertebrates are only 1–3 mm in length! Mites and microscopic organisms like nematodes and bacteria live in the soil.
Adaptations for life in the freezer
Animals and plants that live in Antarctica have special adaptations that allow them to survive in the extreme conditions.
Nigel and Adélie penguins
Nigel visits an Adélie penguin colony at Cape Bird. He learns about their habits and adaptations with scientist Dr Amy Whitehead.
Penguins have thick, windproof and waterproof feathers. Penguins, whales and seals have thick layers of fat called blubber. Blubber acts as an insulator, helping to keep the animals warm. Antarctic animals often have small extremities (flippers and feet) to reduce heat loss.
Nature of science
Dr Amy Whitehead counts Adélie penguins – continuing research that began in the 1980s. Scientific knowledge is developed by a process of on-going inquiry, sometimes over months, years, decades or even centuries.
Plants are small and close to the ground to help protect them from fierce winds and dehydration. Algae can live in spaces between sandstone rocks where moisture and light are available. Lichens can carry out photosynthesis at very, very low temperatures and can survive dry periods by becoming dormant. Some invertebrates intentionally dehydrate to avoid damage caused by freezing.
Humans, ecosystems and adaptations
People living in Antarctica become part of the ecosystem. In the past, we weren’t too worried by this. Adventurers took pack animals to carry goods. Rubbish, huts and fuel spills were left behind when boats arrived to take explorers off the continent and back home. It’s very different today. People living in Antarctica do their best to minimise their impact on the environment.
Nigel walks along the tracks made by others while he crosses the Dry Valleys and carries a special bottle to store his urine to ensure he leaves nothing behind.
One way Nigel and those living at Scott Base cannot avoid changing the landscape is with the buildings and transportation. Unlike the native plants and animals, humans have precious few adaptations for extreme weather living and travel! As an introduced species, we depend on well insulated clothing, buildings and vehicles to survive and navigate the icy continent.
On Thin Ice: Nigel Latta in Antarctica
Watch Series 1/Episode 1
https://adam.antarcticanz.govt.nz/nodes/view/44058
Adélie penguins (video timecode 16:00–25:19)
Dry Valleys terrestrial ecosystems (video timecode 25:30–31:00)
Watch Series 1/Episode 2
https://adam.antarcticanz.govt.nz/nodes/view/44059
Adélie penguins (video timecode 16:30–21:10)
Weddell seals (video timecode 2:25–9:00)
Dry Valleys terrestrial ecosystems (video timecode 24:45–30:40)
Antarctic life
Nigel gets up close with some of the Antarctic natives – from the very big (minke whales) to the very small (springtails). Use these Science Learning Hub resources to read about the animal, plant and microscopic life in Antarctica.
Seals
Penguins
Whales
Fish
Plants on ice
Life in the freezer
Plankton
Deschampsia antarctica
Deschampsia antarctica is one of the grass species found on Antarctica’s peninsula. There are far more plant species on the Antarctic peninsula than the mainland, with the larger number of species at the peninsula’s northern end.
Activity ideas
Nigel sits in a small building (called a room with a view) and muses on Adélie penguin adaptations. These activities also get students musing about adaptations for life in the freezer. Both activities include a literacy component in which students use reading skills to locate and integrate information.
Animal and plant adaptations has students design a unique animal or plant capable of living in Antarctic conditions.
In Hiding in plain sight students investigate fish camouflage adaptations.
The education research article Reading aloud text with secondary students relates how one teacher used these Hub activities to help students with both their reading and their understanding of adaptation.
Antarctic ecosystems
Nigel visits the Dry Valleys and penguin and seal colonies. He chats with Kiwi scientists who study these unique ecosystems. Learn more about ecosystems with these resources:
Ecosystems
Antarctic marine ecosystem
Antarctic terrestrial ecosystem
Benthos – life on the seabed
Food web of the Ross Sea
The bottom of the food chain
NIWA scientist David Bowden explains the importance of the benthic food web and where phytoplankton is being eaten in the water column of the Ross Sea. NIWA scientist Julie Hall talks about the bottom of the food chain in the Antarctic waters, the bacteria, phytoplankton and zooplankton
Points of interest
• In what way does the food chain operate differently in the Ross Sea?
• Julie refers to an unusual place where phytoplankton can be found. Where is this?
The top predators
NIWA scientist Stu Hanchet explains what types of top predators can be found in the Ross Sea.
Points of interest
What are the top predators?
Discuss what would happen if top predators were removed from the food chain ( for example seals or whales).
Activity idea
The activity Making a food web enables students to describe relationships between organisms within the Antarctic ecosystem and build their own food web to show the interdependence of organisms in an ecosystem.
Citizen science projects
These citizen science projects ask for help to analyse images of Antarctic life:
Crabeater Seals – Tomnod – Crabeater seals live in the Southern Ocean surrounding Antarctica and are thought to be one of the most abundant mammals on Earth – but is this really true?
Weddell Seals – Zooniverse – Help analyse images for information about changes in seal population numbers. This work could give important insights into the health and functioning of the Antarctica ecosystem.
Penguin Watch – Zooniverse – Help scientists establish valuable baseline data about the numbers, locations, habits and health of penguins in a range of Southern Ocean sites.
Useful links
Find out more about food webs in our Food webs Pinterest board.
Find out more about the McMurdo Dry Valleys.
Discover more about Adélie penguins and Weddelll seals on the Australian Antarctic Division website.
