Identify two abiotic resources found in each of the following:

(i) continental shelf areas

(ii) ocean floor deposits.

Explain three consequences of oil pollution in oceans.

Examine the effects of the loss of coral reefs and mangrove swamps.

(i) Award 1 mark for each valid resource identified, for example, placer deposits, oil and natural gas.

(ii) Award 1 mark for each valid resource identified, for example, manganese nodules, zinc, phosphates, sulphates, copper, lead, silver.

Possible consequences include:

• reduction in biodiversity
• declining ecological and/or economic productivity
• costs of clean-up operations
• social costs such as loss of livelihoods (short- and long-term unemployment)
• political costs such as after Deepwater Horizon.

Credit other valid consequences.

Award 1 mark for the description or example of each consequence and 1 mark for each explanation.

It is likely that most answers will refer to the possible causes of loss of coral reefs and mangroves as a first step to examining the effects of such loss.

The consequences of the loss of coral reefs are:

• erosion of coastlines
• loss of fish habitats (occupying less than 0.25% of the marine environment, they nevertheless shelter more than 25% of all known fish species)
• loss of biological and economic productivity
• loss of biodiversity
• loss of breeding and feeding grounds for fish
• economic and social loss to people who depend on fishing and/or coral reef tourism/diving.

Some of these effects are similar in the case of mangrove swamps.

In addition, a loss of mangroves may reduce the amount of available food and fuel, building materials and medicine. Mangroves also act as natural filters, absorbing nutrients from farming and sewage disposal.

Both coral reefs and mangroves protect coastlines by absorbing some wave energy, especially during storms such as hurricanes (tropical cyclones). The dense interlocking roads of mangroves help to stabilize shorelines and prevent erosion.

The loss of coral reefs and mangroves is not entirely negative. Removing them may improve navigation. Material eroded from coral reefs can accumulate to form attractive (and economically important) white-sand beaches. The destruction of mangrove swamps may allow for the construction of hotels, harbours and marinas.

Answers accessing markbands E/F should include the consequences of both coral and mangrove loss. Examples would be expected for bands E and F.

Marks should be allocated according to the markbands.

Few candidates had difficulty with this question.

Few candidates had difficulty with this question although it was not always easy for examiners to decide exactly where one consequence ended and the next began.

Responses tended to spend far too long describing causes (not required by the question) and too little time on effects and their consequences. Relatively few responses acknowledged any possible positive effects.