Water Pollution

Question 1

Sources of fresh water pollution:

Answer 1

1. Agricultural run off, sewage, industrial discharge and wild domestic waste.

Question 2

Sources of marine pollution:

Answer 2

Rivers, pipelines, atmosphere, human activities at sea

Question 3

What is biochemical oxygen demand?

Answer 3

A measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity by microorganisms.

Question 4

What is an indicator species?

Answer 4

Plants and animals that show something about the environment by their presence, absence, abundance or scarcity.

Question 5

What is a biotic index?

Answer 5

Indirectly measures pollution by assaying the impact on species within the community according to their tolerance, diversity and relative abundance.

Question 6

example of an indicator species?

Answer 6

Canaries in coal mines. If they died the miners would leave.

Question 7

What is eutrophication?

Answer 7

Eutrophication occurs when excess nutrients are added to an aquatic ecosystem. It can be a natural process but anthropogenic eutrophication is more common.

Question 8

process of eutrophication:

Answer 8

1. fertilizers wash into a water source
2. High levels of phosphates cause algae to grow at a rapid rate as phosphate is often the limiting factor
3. Algal blooms form which blocks out light for underwater plants. They cannot photosynthesise and die.
4. The dead organic matter serves as food for bacteria who respire, using up more oxygen.
5. Soon all oxygen is used up, and the anoxic conditions cause all species to die.
6. Eventually the organic matter forms a sediment but this leaves and the lake is blue again.

Question 9

Eutrophication management strategies:

Answer 9

1. Altering human activity that leads to producing pollution
2. Regulating and reducing the pollutants at the point of emission
3. Clean up and restoration

Question 10

Example of altering human activity producing pollution as a management strategy for eutrophication:

Answer 10

1. Banning or limiting phosphates
2. Use ecodetergents with no phosphates or new technology in washing machines
3. Plant buffer zones between the fields and water courses to absorb the excess nutrients
4. Stop leaching of animal waste or sewage from their sources
5. Educate farmers about more effective timing for fertilizer application

Question 11

Examples of regulating and reducing the pollutants at the point of emission:

Answer 11

Treat wastewater before the release to remove phosphates and nitrates.
Divert or treat sewage waste effectively.
Minimize fertilizer dosage on agricultural lands or use organic matter instead.

Question 12

Examples of clean up and restoration as a management strategy for eutrophication:

Answer 12

Pumping air through lakes
Dredging sediments with high nutrient levels from the river and lake beds
Removing excess weeds physically or by herbicides and algicides.
Restock ponds or water bodies with appropriate organisms.