Unit 5: Oceans and Fisheries TQ:

2-Mark Question

1. Define overfishing.

Model Answer:

Overfishing occurs when fish are caught faster than their populations can reproduce and replace themselves.

Why this works:

• Identifies excessive fishing (1 mark)

• Explains that the rate of removal exceeds reproduction/replacement (2nd mark)

4-Mark Question

2. Explain two environmental impacts of overfishing.

Model Answer:

Decline in fish populations: Catching fish faster than they reproduce reduces the size of fish populations and can cause some species to become endangered.

Food-web disruption: Removing large numbers of one fish species can reduce food availability for predators and cause changes throughout the marine food web.

Why this works:

• Two distinct impacts → 2 marks

• Each impact explained with cause and effect → 2 marks

6-Mark Question

3. Discuss the advantages and disadvantages of marine protected areas (MPAs).

Model Answer:

Marine protected areas restrict activities such as fishing in designated areas, allowing fish populations to recover and reproduce. This can increase biodiversity and may eventually improve fish stocks outside the protected area as fish move into surrounding waters. MPAs can also protect habitats such as coral reefs from damaging human activities.

However, restricting fishing can reduce the income of fishermen who depend on the area for their livelihoods. It can also be difficult and expensive to monitor large marine areas, and illegal fishing may continue if enforcement is weak.

Overall, MPAs can be an effective way of protecting marine ecosystems and fish stocks, but they work best when restrictions are enforced and local fishing communities are involved in management.

Why This Works:

• Benefits are linked to fish populations and biodiversity

• Disadvantages include economic and management issues

• Conclusion evaluates when MPAs are most effective

8-Mark Question

4. Describe methods of managing fish stocks and evaluate their importance.

Model Answer:

Fish stocks can be managed by introducing fishing quotas, which limit the amount of fish that can be caught. Minimum mesh sizes can prevent young fish from being caught before they reproduce, helping maintain future populations. Seasonal fishing bans can protect fish during breeding seasons, while marine protected areas can prevent fishing in important breeding and nursery grounds.

Governments can also restrict the number of fishing boats or issue fishing licences to control the amount of fishing taking place. Monitoring fishing vessels and enforcing regulations can reduce illegal fishing.

These methods are important because maintaining fish stocks ensures that fishing can continue in the future while protecting marine ecosystems and the livelihoods of fishing communities. However, management is only effective when regulations are properly enforced and fishermen cooperate.

Overall, a combination of quotas, protected areas, seasonal restrictions and enforcement is likely to be more effective than relying on one management method alone.

10-Mark Question

5. Assess whether sustainable fishing can provide both economic benefits and protect marine ecosystems.

Model Answer:

Fishing provides important economic benefits by creating employment and providing food and income for coastal communities. However, overfishing can reduce fish populations, damage food webs and threaten the long-term survival of fishing industries. Sustainable fishing aims to maintain fish populations at levels where they can continue to reproduce.

Fishing quotas can limit the number of fish caught, while minimum mesh sizes allow young fish to escape and reproduce. Seasonal bans can protect fish during breeding periods, and marine protected areas can protect important habitats. These strategies can allow fish populations to recover while maintaining fishing opportunities in the long term.

However, sustainable fishing can be difficult to achieve. Fishermen may lose short-term income if quotas are reduced, while illegal fishing can undermine management. Monitoring large oceans is also difficult and expensive.

Overall, sustainable fishing can provide both economic and environmental benefits if fishing levels remain within the reproductive capacity of fish populations. Effective enforcement and cooperation between governments and fishing communities are essential for long-term success.

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