4.3F Conservation and Management of Global Fisheries (HL) Notes

Accurate Fish Stock Assessment

1. Accurate assessment of fish stocks and monitoring of harvest rates are crucial for ensuring that fishing remains sustainable.
2. Without these measures, overfishing can deplete fish populations faster than they can reproduce, leading to ecological imbalance and economic loss.

Methods of Measuring Fish Stocks

1. Catch Data Analysis

1. Data collected from commercial and recreational catches provide insight into the number and types of fish being caught.
2. Information includes species, size, and weight of the catch, helping to estimate the population’s distribution and abundance.
3. This data can reveal whether the population is stable, growing, or declining.

2. Tag and Recapture Studies

1. Individual fish are captured, tagged, released, and later recaptured to estimate population size, growth rate, and movement.
2. This method provides direct, field-based data on population dynamics.

3. Scientific Research Surveys

1. Conducted using research vessels that employ sonar, trawl nets, or underwater cameras to estimate population abundance.
2. Surveys can detect fish distribution patterns and age structures.

4. Logbook Monitoring

1. Fishers maintain logbooks recording catch quantities, fishing locations, and gear types.
2. In countries like the UK, vessels must submit data within 48 hours of docking.
3. These records help monitor compliance with quotas and detect changes in harvest rates.

Monitoring Harvest Rates

1. Harvest rates represent how much of a stock is removed by fishing.
2. Monitoring ensures catches remain below levels that threaten population sustainability.
   1. Electronic Monitoring Systems (EMS): Cameras and sensors on vessels record fishing activity.
   2. Catch-per-unit-effort (CPUE): Compares catch volume to fishing effort (e.g., hours or number of nets). A decreasing CPUE suggests declining stock abundance.
   3. Satellite Tracking: Monitors vessel locations to prevent illegal fishing and ensure compliance.

Risks of Harvesting at Maximum Sustainable Yield (MSY)

1. The Maximum Sustainable Yield (MSY) is the largest catch that can be taken from a fish population without causing long-term decline.
2. However, this concept has limitations.

1. Inaccuracy in Data

1. MSY calculations rely on estimates of carrying capacity, population growth rate, and reproductive rate.
2. These parameters fluctuate with temperature, salinity, and predation levels.

2. Positive Feedback Risk

1. Overharvesting reduces reproductive potential.
2. Fewer fish breed → smaller future generations → further decline.
3. Can cause rapid collapse of fish stocks.

3. Economic and Enforcement Challenges

1. Fishing crews may exceed quotas due to economic pressure or lack of monitoring.
2. Illegal, unreported, and unregulated (IUU) fishing undermines sustainable management.

Stakeholder Cooperation in Recovery of Overexploited Species

1. Governments

1. Implement fishing bans, quotas, and licensing limits.
2. Enforce seasonal closures to allow reproduction.
3. Coordinate international treaties for migratory species.

2. Fishing Industry

1. Adopts selective gear to reduce bycatch.
2. Supports catch-and-release or closed-season practices.
3. Invests in aquaculture as an alternative source.

3. Consumers

1. Influence sustainability through purchasing behavior.
2. Look for Marine Stewardship Council (MSC) certification labels.

4. Non-Governmental Organizations (NGOs)

1. Advocate for policy change and public awareness.
2. Monitor compliance and support conservation research.

5. Retailers and Markets

1. Promote sustainably sourced seafood.
2. Label products clearly to inform consumer choice.

Ethical and Legal Regulation of Marine Harvesting

United Nations Convention on the Law of the Sea (UNCLOS)

1. Established in 1982 to regulate marine resources and protect the oceans.
2. Defines maritime zones with different levels of national control.
   1. Internal Waters: Full sovereignty of the coastal state.
   2. Territorial Sea: Extends up to 12 nautical miles (22.2 km) from the coast.
   3. Contiguous Zone: Extends up to 24 nautical miles; allows enforcement of laws on customs, immigration, and pollution.
   4. Exclusive Economic Zone (EEZ): Extends 200 nautical miles (370 km); states have exclusive rights to explore, exploit, and manage resources.
   5. High Seas: Beyond EEZs; governed by international law and open to all nations.

Equity and Justice Issues in EEZs

1. Some low-income countries sell fishing rights in their EEZs to foreign corporations.
2. This can lead to economic inequality, resource depletion, and loss of livelihoods for local fishers.
3. Wealthy nations may overexploit these zones, leaving little for local consumption.

Global Governance Beyond EEZs

1. 60% of the ocean lies outside EEZs (the high seas) with limited regulation.
2. The UN High Seas Treaty (2023) aims to create marine protected areas and strengthen global governance.