Biodiversity is the variety of life and is essential to the survival of all species in the environment. Ecosystems combine all the different plants, animals and micro-organisms and the unique marine and terrestrial environments they exist in. The more diverse an ecosystem is, the more chance it has of surviving if one part of the system is damaged. Life exists because the Earth has organisms that can photosynthesise. Plants are able to use the energy from the sun to make new chemical bonds between water molecules and carbon dioxide. This matter is then cycled through all other organisms when they consume other organisms. Energy is transferred when the chemical bonds of the matter (or nutrients) are metabolised by the consumers.
Food chains and webs explain the relationship between all the organisms in an ecosystem. A food chain shows the flow of energy from the producers through the consumers. A food web combines a group of food chains and a very complex way, showing how each organism fits into the ecosystem. If any of the links in a food web are damaged, many organisms in the web may be affected.
The marine ecosystem in Antarctica is centred around the animals and plants of the Southern Ocean. The main marine animals in the Southern Ocean are whales, penguins, seals, seabirds, fish, squid and zooplankton (including krill). The plants in the marine Antarctic marine environment are predominantly phytoplankton which are microscopic (usually less that 1mm across). It is difficult for many plants to survive in the oceans around Antarctica as the ice sheet acts as a kind of curtain preventing sunlight from coming through to aid photosynthesis, however some of these plants rely on the sea ice for winter survival. Phytoplankton are often incorporated into the sea ice and grow in thick bands on the underside of the ice. In spring, as the ice melts, phytoplankton is produced in enormous numbers and forms the base of the Antarctic food chain. Krill (and other zooplankton) graze on phytoplankton. In turn, krill are the major food source for whales, penguins, seals and many birds.
Students will develop an understanding of the relationship between Antarctic producers, grazers, prey and predators by role play.
Record the sequence of “dropping” for each round. Discuss the results.
Change the animals in the game or become more specific about species of animals (e.g. seals become Weddell seals, Crabeater seals, and Leopard seals).
Incorporate other environmental components into the game (e.g. human impact, low light, frozen seas, the hole in the ozone layer and UV damage, excessive algal blooms, toxic algal blooms, pollution etc.).
(Adapted from Antarctic Science – A resource book of ideas for teachers for National Science Week, 2007, ASTA)