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Date May 2013 Marks available 6 Reference code 13M.2.bp.3
Level SL and HL Paper 2 Time zone
Command term Explain Question number 3 Adapted from N/A

Question

Describe the size and location of the oceanic “garbage patch” shown.

[4]
a.

Explain why most types of ocean pollution occur along coastal margins.

[6]
b.

Compare the conflicts that arise in coastal areas from habitat restoration schemes with those that arise from aquaculture.

[10]
c.

Markscheme

The garbage patch is approximately 5000 to 6000 km long (west to east) [1 mark] and 500 to 600 km wide (north to south) [1 mark].

Likely responses include the middle of the Pacific Ocean [1 mark], towards the sub-tropics/tropics [1 mark], inside a major ocean current cell/gyre/loop [1 mark] (such as the North Pacific current, the North Equatorial Current and the Kuroshio current), latitude 30°N, longitude 140°W to 160°E [1 mark].

Award [1 mark] for each valid point and a further [1 mark] for additional detail.

a.

Most oceanic pollution occurs relatively close to its source. Award [2 marks] for indentifying different types of oceanic pollution (solids, solutes, radioactive materials, oil and chemical wastes). Likely coastal sources of pollution include landbased sewer systems, river systems, ports, a range of local industry including nuclear [2 marks]. Award the remaining [2 marks] for explanation of oil tankers, sea-trading vessels and fishing vessels producing pollution that is moved onshore by ocean currents and/or wind systems; or noting that ocean currents can move pollution towards coastal margins of sparsely populated areas eg Alaskan wilderness.

b.

Conflicts associated with managing habitat restoration include conflicts between local residents, industrialists, environmentalists. Attempts to manage restoration could include introducing clean-up programmes, limits to visitor access and species reintroduction, etc. The source of the conflicts may include costs, funding, employment, local involvement, etc.

For aquaculture, conflicts might develop as a result of the introduction of exotic species, the transmission of disease, the release of chemicals into the water. There may be conflict between the aquaculture industry and local fishermen, environmentalists, water safety personnel, for example.

To access band D, both sets of conflicts must be described (balance is not necessary). At bands E and F, there should be some explicit comparison (eg severity, similar or different causes, or stakeholders).

Marks should be allocated according to the markbands.

c.

Examiners report

This question proved challenging, with many unable to describe both size and location effectively.

a.

Quite a good knowledge and understanding of types and sources of coastal pollution.

b.

This question was generally poorly answered. Many candidates do not understand the meaning of the term “aquaculture”, choosing to write about overfishing, and there were few examples of habitat restoration. They also found it difficult to compare the conflicts. Some misinterpreted the question assuming there was a choice between aquaculture or habitat restoration in a region.

c.

Syllabus sections

Optional themes » Option B: Oceans and their coastal margins » The value of oceans » Waste

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