Pollution and Bio-indicators The job of the environmental agency is to protect our ecosystems.

Healthy pond ecosystemunhealthy pond ecosystem As an agent for the environment agency you will have to take samples of pond and river water, especially those that are based near farm land. Farmers use fertilisers on their land to increase productivity and keep the price of food in supermarkets down, BUT... If nitrates on the land are washed off into streams, rivers, ponds by heavy rain they can have devastating effects.

Lichens as Bio-indicators Lichens are alga and fungi living symbiotically (they have to live together to survive) The alga make sugars by photosynthesis and gives some to the fungus The fungus delivers water and minerals to the alga

Lichens are used for reindeer food, dying wool, medicines and even perfumes. Lichens can live in extreme conditions, but they hate pollution The cleaner the air the bigger and more elaborate the lichen So by looking at the lichens growing in a certain area you can tell how bad the air pollution is This is why lichens are used as bio-indicators or air pollution detectors info

Use the pictures of lichens to put the Lichens in order of air pollution Remember the bigger and more elaborate the less air pollution

Check your answers These are called Crusty These are called Flakey These are called Leafy These are called Shrubby

Task 3 Draw up a tally chart and go on a lichen hunt around the school grounds recording what you see. When you come back discuss your findings... 1.What can you conclude about the air pollution around the school grounds? 2.Where do you think air pollution comes from? 3.Predict what do you think you would see if a new motorway was built near by? 4.If all traffic was banned near the school what do you think would happen to the lichens?

Now carry out the data handling task on the lichen worksheet.

Indicator species – Invertebrate as indicator of water pollution Rat tailed maggot Live in sewage polluted water Flatworm Live in slightly polluted water Fresh water shrimp Live only in fresh water You can determine if the water is polluted by collecting a sample of suspected water and analysis the type of animals that are in the sample.

Why do you think fish be a good pollution indication? Fish need oxygen to live in the water. Water pollution effects the oxygen level in the water. If the water is so polluted the oxygen levels will fall and fish will die. This is how fish are a good indicator or pollution.

Use page 54 of your textbook to find explain what BOD stands for and how scientists might use this.