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The table below gives information about the sources of marine pollution - NSC Life Sciences - Question 3 - 2018 - Paper 1
Question 3
The table below gives information about the sources of marine pollution. | SOURCES OF MARINE POLLUTION | PERCENTAGE CONTRIBUTION TO POLLUTION | |-------------------... show full transcript
Worked Solution & Example Answer:The table below gives information about the sources of marine pollution - NSC Life Sciences - Question 3 - 2018 - Paper 1
Step 1
Draw a bar graph to represent the percentage contribution of sewage, farm runoff, industrial waste and organic litter to marine pollution.
Answer
To represent the percentage contributions accurately, start by setting up your axes. The horizontal axis (X-axis) will list the sources of marine pollution: Sewage, Farm runoff, Industrial waste, and Organic litter. The vertical axis (Y-axis) should represent the percentage contribution, ranging from 0 to 35, with appropriate increments.
Use equal widths for the bars and space them evenly. Each bar's height should correspond to the percentage of pollution contributed by each source:
- Sewage: 30%
- Farm runoff: 20%
- Industrial waste: 10%
- Organic litter: 5%
Make sure to title the graph appropriately, label both axes clearly, and provide units for the Y-axis. Ensure that all bars are plotted accurately and reflect the data provided.
Step 2
Describe how this pollution reduces oxygen levels in the water.
Answer
Untreated sewage and organic litter contribute nutrients to the water, leading to a process known as eutrophication. As the concentration of nutrients increases, it promotes algal blooms. These blooms cover the surface of the water, blocking sunlight from reaching aquatic plants.
Consequently, plant life suffers as they cannot photosynthesize effectively. The decomposition of organic matter, including the dead algae, consumes more oxygen in the water, further depleting the oxygen levels necessary for fish and other marine organisms to survive. This can lead to hypoxic conditions, where oxygen levels become uncomfortably low, resulting in the death of fish and other aquatic life.