B2: water pollution Learning Objectives Know that water pollution causes changes to the types/amount of animals at a water source (all) Understand what an indicator species is and how testing for indicator species gives us information on pollution in water samples (all) Know why certain indicator species occur in certain places (most) Success Criteria Correctly draw out a table of indicator species Correctly answer 6 questions on indicator species
Being responsible for your rubbish Family watched TV programme on water becoming contaminated by plastic rubbish Set themselves a goal of only producing one bag of rubbish per year. This is VERY COOL – considering that most families produce 1-2 bags per week How do you think they did it? Write down 5 ways you think they reduced their rubbish.
Took own containers to butchers and supermarket deli counter Only bought food that was not in any packaging Took own bags to supermarket Grew own vegetables Composted waste vegetables and fruit Re-used any packaging they had Found it was no extra cost and no extra trouble once they had the routine What do you think about this? What can you do to be more responsible about how much you throw away? Write down (at least) 3 things you will try and do to reduce the amount of rubbish you produce.
This year the family aim to not produce any rubbish at all RESPECT!
Carry on: Draw a mind map/poster On your poster/mind map: Summarise the issue of population growth and use of fossil fuels Describe the pollution effects: Global warming (climate change) Ozone layer depletion Acid rain Population and pollution
River damage caused by pollution Insect species change – some like polluted water, some only like clean water Kills fish River damage caused by pollution Kills plants Has knock-on effects up the food chain
How do we detect pollution in rivers? Look for whether an indicator species lives there Some insects only like clean water Some insects only like polluted water
Definition of Indicator Species Write this down! Definition of Indicator Species An indicator species is a species whose presence/absence tells you something about the pollution levels and oxygen levels.
Type of pollution linked to Present in clean or polluted areas? Draw out this table and fill it in as we look at some indicator species Species Type of pollution linked to Present in clean or polluted areas? Reason Bloodworm Water Louse Sludge Worm Alderfly Rat-tailed Maggot Lichen
Water Pollution – Bloodworm Indicate high levels of pollution
Water Pollution: Water Louse Indicate high levels of pollution
Water Pollution: Sludge Worm Indicate very high levels of pollution as it can cope with low levels of oxygen
Water Pollution: Alderfly The alderfly cannot live in polluted water as it cannot cope with low oxygen levels
Water Pollution: Rat-tailed maggot Indicate very high levels of pollution
Air Pollution: Lichen Indicate low pollution (killed by sulphur dioxide)
Type of pollution linked to Present in clean or polluted areas? Species Type of pollution linked to Present in clean or polluted areas? Reason Bloodworm Water Polluted Tolerant of a wide range of environmental conditions Water Louse Tolerant of a range of pollutants Sludge Worm Can cope with low oxygen levels Alderfly Clean Cannot tolerate low oxygen levels Rat-tailed Maggot Lichen Air Killed by sulphur dioxide
We would have done a practical now with some pond and river water – analysing what animals we can find and what this indicates. However, it is winter and therefore there are not many indicator species found in the ponds around here. So I’ll have to tell you how we would have done it instead....
Measuring water quality You would take a water sample Find the animals in the sample and identify them, classify them and count them You would then multiply the number of each animal from each classification by a specific factor (a given number that has been formulated to be used for indicating cleanliness) There will be a different factor for each classification of animals The number you get in the end can then be divided by the total number of animals and compared to a chart which will tell you how clean the water is – e.g.: How clean is your water sample? excellent 3.6+ good 2.6–3.5 fair 2.1–2.5 poor 1.0–2.0
Measuring Pollution What other things might you measure in a river/pond to work out pollution? Oxygen levels – measured by oxygen probes attached to computers Nitrate levels – special chemicals can be used to work out nitrate levels from fertiliser run off
Scan in pink box of questions – p.83 textbook
Another question A scientist compares oxygen levels in two different ponds. He uses both living and non-living methods. Describe the two different methods he uses. Describe advantages and disadvantages of both methods
plenary 1) A pond has a large amount of water louse and sludge worm with a small amount of alderfly. What would this indicate? It is polluted 2) Why would it be more difficult to find lichen growing in cities? Air pollution kills lichen 3) You receive a water sample containing a very high number of alderfly. What type of source do you think this could have come from? (Higher – but Foundation people try to answer it!) Possibly a rapidly flowing river