Indicator Species - Paper 2 Flashcards
(17 cards)
What is an indicator species?
Organisms whose presence, abundance or absence suggests the pollution level in an environment
Name two species which might be found in polluted water
Bloodworms
Sludgeworm
Both are tolerant (can survive in) water with low oxygen levels
Polluted water has low oxygen levels because of increased oxygen usage by the increased aerobic respiration by decomposers to break down the increased quanitity of dead organic water typically found in polluted water (e.g. sewage water)
Why might you find bloodworms and sludgeworms in polluted water?
Polluted water has less oxygen due to decomposers using it during aerobic respiration.
Bloodworms and sludgeworms can survive in adverse conditions (like decreased oxygen levels) unlike lots of other species.
Increased oxygen usage via increased aerobic respiration from decomposers because polluted water (e.g. sewage contaminated water) has more dead organic matter in it to break down
Describe the oxygen levels in polluted water
Decreased
Name a species whose presence suggests clean, well-oxygenated water (1 mark)
Stonefly
Freshwater shrimp
Give one example of an indicator species for air pollution and explain what its presence or absence shows (2 marks)
Presence of bushy lichen suggests clean, unpolluted air with low levels of sulfur dioxide (dissolved in rain)
Explain why the presence of bloodworms in a pond suggests that the water is polluted. (3 marks)
Bloodworms are found in polluted water because they can survive in low oxygen levels. Pollution increases the number of decomposers, which use up oxygen during their aerobic respiration.
Describe how indicator species can be used to monitor both water and air pollution. Use examples in your answer. (4 marks)
Indicator species can be used to monitor environmental pollution.
Bloodworms are found in polluted water because they can survive in low oxygen levels, caused by the increase pollution causes in decomposers using up oxygen during aerobic respiration. In contrast, many other species cannot survive in these conditions.
For air pollution, lichens are sensitive to sulfur dioxide. If no lichens are present, it suggests high levels of sulfur dioxide in the air, often from fossil fuel combustion. However, the presence of bushy lichens suggests clean air with low sulfur dioxide levels.
What might cause increased sulfur dioxide levels?
Fossil fuel combustion (e.g. in cars)
Which substance dissolved in rain are lichens sensitive to?
Sulphur dioxide
In which conditions might you find crusty lichens?
Moderate levels of air pollution
Give a way to determine between different levels of water pollution
Indicator species
Very low water pollution - stoneflies
Low water pollution - freshwater shrimp
Moderate water pollution - bloodworms
High water pollution - sludgeworms
Extremely high water pollution - no living insects
State two indicator species for air pollution
Blackspot fungus on roses
Lichens
Name two indicator species sensitive to sulphur dioxide
Lichens
Blackspot fungus
Being sensitive to SO2 means that an organism cannot survive or grow well when sulfur dioxide (SO₂) is present in the air, even in small amounts.
Order the 3 lichen species from most to least sensitive to SO2
Bushy
Leafy
Crusty
What is blackspot fungus on roses an indicator species for?
Air pollution
Sulphur dioxide levels (if present, SO2 is low)
What are lichens an indicator species for?
Air pollution
Sulphur dioxide levels
(if bushy lichens present, SO2 is low; if leafy lichens present, SO2 is slightly higher but still low; if crusty lichens present, SO2 levels are moderate; if no lichens present, SO2 levels are high)
