Date | May 2015 | Marks available | 6 | Reference code | 15M.2.hl.4 |
Level | HL only | Paper | 2 | Time zone | |
Command term | Explain | Question number | 4 | Adapted from | N/A |
Question
The photograph shows an actively eroding cliff.
State two subaerial processes that may affect the cliff in the photograph and briefly outline how each process operates.
Explain two conflicts that could arise from attempts to manage cliff failure.
Examine the contribution that conservation can make to protecting oceanic fish stocks.
Markscheme
Accept a wide range of processes, provided they are non-marine processes.
Award [1] for each process and [1] for an outline of how the process operates.
Subaerial processes can include mass movements, surface run-off and various types of weathering.
Possible examples include:
- slumping/mass movement [1] is when a cliff collapses due to overlying rock strata/saturated soil becoming unstable/shear strength exceeds resistance [1]
- salt weathering [1] (allow chemical weathering on the cliffs). Salt crystals expand and cause stress to occur in many rocks, leading to disintegration and flaking [1]
- freeze-thaw [1] when fluctuating temperatures allow water to freeze and shatter cliff face [1]
- biological weathering [1] when tree roots (physical)/organic acids (chemical) disintegrate/decompose cliff [1]
- surface run-off [1] occurs when precipitation falling on the land runs over the cliff face leading to gullying/carries away sediment under gravity [1].
Conflicts may be about governance, cost, impacts on different stakeholders, degree of sustainability, aesthetics etc.
Award [1] for a description of the cliff management technique that shows how it prevents failure, [1] for identification of the nature of the conflict/the groups in conflict, and [1] for the explanation of the conflict.
For example: There may be conflicts between people wishing to use a beach for recreation and those trying to prevent coastal erosion [1] eg the use of tetrapods/rip-rap to absorb wave energy [1] on some beaches has reduced the recreational amenity [1].
Credit any other valid points.
Candidates may agree that conservation policies are needed or else the world’s fisheries become unsustainable. Examples could include the decline of certain fishing grounds such as the Grand Banks of Newfoundland or the North Sea. Particular species may be identified – blue fin tuna, cod, whales etc.
Methods to conserve fish stocks and make fishing more sustainable include:
- reducing the fishing yields by restricting time spent at sea, the size and number of boats
- imposing fishing permits, quotas and import tariffs
- preventing improvements in efficiency, by increasing mesh size and discouraging the marketing of juvenile fish.
Good answers may recognize there are limits to protection due to rising demand, illegal fishing, factory fishing, changes in technology, so protection is not guaranteed. They may also question the scale of protection (some places may be easier than others to manage sustainably; some fish stocks may be more easily conserved). Another approach may be to argue that other methods are needed to make a contribution too, including an increase in aquaculture that could produce enough fish to meet demand.
For band D, expect some description of marine conservation.
At band E, expect either more detailed explanation of marine conservation or a structured examination of different methods (or scales) of conservation.
At band F expect both of these elements.
Examiners report
The focus of the question was subaerial processes, although many referred erroneously to marine processes. Mass movement was rarely mentioned.
Some reasonable attempts were made to identify the cliff management and sources of conflict, but in most cases there was not enough development. Strong candidates identified possible conflicts and different interest groups with several referring to actual examples.
Candidates were able to identify different methods of marine conservation and recognized the reasons for the need and likely trends in the future. However, knowledge of case studies was variable, often lacking specific detail. Alternatives to conservation were often not considered.