How Science Works Focus

Outline activity plan – Pollution How Science Works focus Collection and analysis of scientific data. Communication skills analysing, interpreting scientific information.

Breadth of study context Explore information about the causes for the destruction of habitat and reduced biodiversity. Know that water may become polluted by fertilisers and untreated sewage which may cause rapid growth of water plants. Plants die and are decayed by microbes which use oxygen in the water so affecting fish. Explore information about heavy metals which are present in industrial waste and the types of pesticides used on crops. Some of these toxic chemicals enter the food chain, accumulate in animal bodies and may reach a toxic level. Understand the need to monitor the effects and control the use of these chemicals. Objective(s) 1. Pupils to explore the effects of pollution on the river environment. 2. Know that invertebrates may be used to determine pollution levels, and use this information to investigate the effects of pollution on a river. 3. Analyse data on levels of nitrate/oxygen in water samples to determine the effect on organisms. Planned sequence of activity Starter 1. Presentation including image of river and industries on river bank. Two photos of the river, one before industrial area, one at bottom of industrial area. Pupils to discuss the images, and reasons behind the change. River 1 file. 2. Pupils to fill the tree map map and compare the effects of each industry on the river – Tree Map file.

Main Session – River 2 file. (Including Invertebrates and Indicator files) 1. Question sheet and analysis of water samples from the river. Pupils to study 3 samples of water. a) clean water with stonefly larva, alderfly, molluscs, high oxygen level. b) medium polluted water with molluscs, mayfly larva, caddis-fly larva, medium oxygen level. c) high pollution level with tubifex, blood worms, low oxygen level. It’s also possible to measure oxygen levels using data loggers and oxygen probes. 2. Pupils to complete the graph showing the changes in oxygen and nitrates as you travel down the river.

Plenary 1. Put the statements of eutrophication in order. River 2 file, last screen. Resources  Presentation  Worksheets  Water samples with invertebrates: if this is unavailable it’s possible to use plastic bags with laminated images of the invertebrates to re-create the above samples.

Advice/instructions for the teacher  Pupils should have an understanding of eutrophication, this activity is to re-enforce their knowledge on eutrophication and link the process to industry and pollution.  Resources need to be laminated in advance.

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