Using living things to tell us levels of pollution

Using living things to tell us levels of pollution

Activity 5 Learning Intentions Give examples of sources of pollution and the ecosystems that they effect Explain the meaning of the term indicator species Give named examples of river indicator species and the level of pollution that they show. Describe how pollution effects river ecosystems Describe how different types of lichens show different levels of air pollution. Success Criteria I can contribute to a class discussion to demonstrate any knowledge I have on pollution I can write a few sentences to describe pollution in the river and species that allow the level of pollution to be assessed I have made sewage in a bottle and understand the reason each component (ingredient) was added I can place indicator species into their preferred water environment

Living organisms can be used as indicators of pollution. You need to understand two ways of identifying pollution... 1. How Lichens are used as indicators of air pollution. 2. How invertebrate animals are used as indicators of water pollution.

Have you ever seen plants like this? Where might you see them?

What are lichens? Lichens are similar organisms to algea or fungi. There are more than 1,700 species of lichen in Britain. Approximately 18,000 species of lichen have been described and identified worldwide. Why are Lichens used as pollution indications? Lichens absorb water and minerals from rainwater and directly from the atmosphere, over their entire surface area. This makes them extremely sensitive to atmospheric pollution. As a result, there are usually very few lichens around industrial centres and towns. Different lichen species vary in their tolerance to pollution and therefore make very good biological indicators of levels of atmospheric pollution.

Indicators of air pollution Lichens are plants that grow in exposed places such as rocks or tree bark. Air pollutants, especially sulphur dioxide, can damage lichens, and prevent them from growing. This makes lichens natural indicators of air pollution. For example: Green, bushy lichens need really clean air leafy lichens can survive a small amount of air pollution crusty lichens can survive in more polluted air In places where no lichens are growing, it's often a sign that the air is heavily polluted with sulphur dioxide.

Indicators of water pollution Scientists can take samples of the invertebrate animals living in a river to see if it is polluted. Some invertebrates are able to live in polluted water and some are not.

Indicator species Invertebrate as indicator of water pollution 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. Rat tailed maggot Live in sewage polluted water Flatworm Live in slightly polluted water Fresh water shrimp Live only in fresh water

Indicators of water pollution Polluted water cloudy, smelly with low levels of oxygen Invertebrates found: Not many different species. Mostly worms and leeches.

Indicators of water pollution Slightly polluted water less cloudy and smelly, oxygen levels rising. Invertebrates found: more species: molluscs (snails), some beetles.

Indicators of water pollution Clean water clear water, high levels of oxygen. Invertebrates found: Many different species. Will begin to find shrimps and mayfly larva which will not tolerate any pollution.

Highly polluted Moderately polluted No pollution 1. Why are lichens useful pollution indications? 2. Why will you not see many types of lichens growing around factories?

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.

List as many things as possible as to how you know if an area is polluted or not? What would you see or smell?

A scientist surveyed the distribution of lichens. She counted the number of different species that grew on trees at various distances from the centre of a polluted city. Here are her results: Distance to the town centre (km) Number of different species of lichen 0 1 2 3 4 5 6 7 8 9 10 0 1 2 6 8 10 30 44 51 56 56 1. What was her independent and dependent variables? 2. Explain fully the relationship between the number of species and the distance from the centre of the city. 3. What do these results show about the levels of pollution as you get further from the city centre? Explain how you know. 4. Can you see any errors that could have arisen in this investigation?