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.

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.

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.

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.