What is an ecosystem?

An ecosystem means all living and non-living things interconnected in an area. Ecosystems are everywhere and range in size, from one small stream or garden pond, to forests and oceans and the entire planet.


What is biodiversity?

Biodiversity, short for biological diversity, is the variety of different living things within a particular area including all life forms such as animals, plants, fungi, even microscopic bacteria. The organisms are all dependent on each other for food and shelter (see Food chains activity below).  Some places will naturally have greater biodiversity than others. The coral reef in Australia has over 500 types of fish, while a garden pond may only have one or two types. In the whole of the UK there are thought to be over 88,000 different species of animals, plants and fungi.


Why does biodiversity matter?

Because the different species depend on each other ecosystems with high biodiversity are healthier and means they can survive more easily if one species dies out. Protecting habitats not only helps the animals and plants living there it often means the land is improved and fewer harmful chemicals are used which means the water flowing over it is cleaner which means we have to do less in the water treatment process to make the water safe to drink and use.

Our landscape has changed a lot.  In towns there are lots of roads and hard surfaces which means when it rains heavily the water cannot sink into the rocks underneath but flows quickly over the surface and can cause floods if the drains fill up. Wilder habitats can allow the natural landscape to hold more water. Trees and hedgerows are valuable habitats for wildlife.


Looking after our land helps protect our raw water sources but also helps animals and plants, it can protect against flooding and help tackle climate change as well as being good for our own well-being. (Check back to the section on climate change to see why carbon dioxide is a problem.)


What do we do?

We own a lot of land at our treatment works and other sites so we are working hard to improve it and protect it and create homes for all kinds of wildlife

  • construction projects are carefully planned to avoid and minimise harm to wildlife
  • we carry out surveys so we know what wildlife we need to protect
  • we work in partnership with organisations like the Wildlife Trust
  • we don’t cut the grass as much and leave areas for wildflowers to grow
  • we put up bat boxes, bird boxes and leave dead wood piles to encourage insects (you can build an insect hotel too, see below)


Biodiversity Benchmark Award

In January 2021, we were awarded The Wildlife Trusts’ Biodiversity Benchmark for improving and protecting the land at our Elmer Water Treatment Works and making it more attractive for butterflies, dormice, badgers, lizards and slow worms.


Food Chains


Ecosystems are made up of connected food chains.

We get our energy from the food we eat. Just the same happens in nature, herbivores (plant-eating animals) eat plants for food and carnivores (meat-eating animals) eat other animals, omnivores eat both plants and animals.

A food chain is a way of explaining how the energy is being passed along and starts with a plant, which is called the producer; plants usually get their energy from sunlight. The producer is then eaten by a consumer.

Here is an example – leaves are eaten by slugs and slugs are eaten by a blackbird and the blackbird might get eaten by a fox. The energy was produced by the leaf and passed along in this case to the fox. Food chains are often written with arrows to show the energy being passed along.

Food Chain

A water habitat food chain

Think about a pond or a river. The producer will be the plants and algae that grow in the water, these are consumed by small water creatures such as water beetles or dragonflies, these are consumed by a fish and the fish might get consumed by a bird such as a heron or a kingfisher.

Make your own food chain for a pond

Food Chain

Cut out 4 rectangular strips of paper about 20 cm x 3cm

Food Chains

On one draw the algae or water plant, on the next one draw either a water beetle or dragonfly, draw a fish on another one and finally the bird. (You might need to do some research to see what they look like.) Then starting with the algae or plant join them together to make a paper chain but in this case it is a food chain!

Food Chains

Remember all living things depend on each other. If one part of an ecosystem is changed, this may affect other living things in the ecosystem. So, if the water beetles in our example all died then the fish and the bird would have less to eat. This is why we need to protect our wildlife and make sure that there is a wide range of biodiversity. In this case the fish could eat the dragonflies instead if there were no water beetles; however this would then affect the dragonfly population!

If you enjoyed doing this why not do some more research and produce more paper food chains not just for water habitats.

See what the next activity is... build an Insect Hotel

Food Chains


Help create a home for the insects in your garden. Bees in particular are under threat as they have lost a lot of their natural habitat, we need bees as they help to pollinate the plants and flowers.

You will need

Insect Hotel

All you need is an empty plastic bottle, scissors, twigs, bamboo canes, fir cones and string.

  1. Wash your bottle and carefully cut off the top.
  2. Then pack it tightly with bamboo canes or bundles of sticks or even old fir cones. Anything that will create small spaces for the insects to hideaway in and lay their eggs. Make sure your twigs and canes do not stick out of the bottle otherwise they will get wet.
  3. Then place it somewhere off the ground perhaps in a bush or a hedge or under a tree. You may want to use string to hang it up. You will know if insects are using your hotel as they will block the gaps to the holes with leaves and mud.