What is a food chain?

A food chain is a term given to a series of animals and plants that are linked together by one eating the other. In the ocean, a simple example of a food chain is:

As you move up the food chain, there is a huge drop off in the number of animals. For example, for every million tonnes of phytoplankton, their might be only 10 kilograms of seal and one kilogram of killer whale / large shark.

Food chains give a useful, but very simplified idea of what goes on. There are thousands of different animals in the ocean and each has a different role. By connecting lines between who eats who, you get a really complicated mess of lines, but it is closer to reality and is called a food web.

To learn more about what Australian Fur Seals eat and their role in the food web please click on the side tabs.