Mitigation Strategies (HL IB ESS OLD COURSE - IGNORE)

Revision Note

Mitigation Strategies

  • Unsustainable exploitation of aquatic systems can be mitigated at a variety of levels (international, national, local and individual)

    • This can be achieved through policy, legislation and changes in consumer behaviour

      • For example, control of net size and the introduction of fishing quotas play important roles in the conservation of fish stocks

      • Strategies like these can keep fish stocks at a sustainable level

International and National Level Actions

  • Increasing the size of gaps in fishing nets can help in two main ways:

    • Fewer unwanted species (that are often discarded) will be caught and killed

      • This is because they can escape through larger net gaps (as long as they are smaller than the species being caught)

      • The accidental capture and killing of larger, unwanted species is still a problem

    • Juvenile fish of the fish species being caught can escape through larger net gaps

      • This means they can reach breeding age and have offspring before they are caught and killed

      • This ensures the population of the fish species being caught can be replenished

  • Fishing quotas limit the number and size of particular fish species that can be caught in a given area

    • Many nations have introduced quotas to prevent overfishing of certain species

  • There are several ways to enforce governmental regulations:

    • Establishing fishing quotas

    • Agreeing zones or areas of the ocean where fishing is banned (e.g. spawning grounds) and permitted (e.g. within a country's territorial waters)

    • Agreeing specific times of the year when fishing is not allowed to let fish populations recover (e.g. spawning season)

    • Regulating mesh size of nets (to allow undersized/juvenile fish to escape)

    • Limiting the size of the fishing fleet by issuing licences and permits

    • Inspecting the catch as a fishing boat returns to port

    • Banning certain practices, e.g. gillnets (static nets that catch anything that swims past),

    • Promoting sustainable practices such as trolling (different to trawling) that reduce bycatch

    Illustration of a fishing boat in the ocean with multiple fishing lines in the water, a technique known as trolling.
    Trolling uses hook-and-line and reduces bycatch and damage to the seabed

Local and Individual Level Actions

  • Sustainable seafood choices:

    • Encouraging consumers to buy seafood that is certified as sustainable

      • For example, the Marine Stewardship Council (MSC) label indicates sustainably sourced seafood

  • Food labelling:

    • Providing clear information on the origin and sustainability of seafood products to help consumers make informed choices

      • For example, the UK’s “Blue Fish” label signifies fish caught using sustainable practices

  • Community initiatives:

    • Educating the public about the importance of sustainable fishing and responsible seafood consumption

    • Supporting local fishing communities that practice sustainable fishing

    • Participating in local conservation efforts

    • Involving local communities in managing and protecting their own fisheries

      • For example, in the Philippines, community-based coastal resource management has successfully increased fish stocks and biodiversity

Marine Protected Areas

  • Marine Protected Areas (MPAs) are designated regions of seas and oceans where human activities are restricted or managed

    • This is to protect marine ecosystems and biodiversity

  • MPAs play a crucial role in supporting aquatic food chains and maintaining sustainable yields

    • They do this by providing safe areas for marine life

Benefits of marine protected areas

Biodiversity conservation

  • Habitat protection:

    • MPAs protect critical habitats like coral reefs, seagrass beds and mangroves

      • For example, the Great Barrier Reef Marine Park protects one of the most biodiverse ecosystems on the planet

  • Species protection:

    • MPAs protect endangered and vulnerable species by reducing human-induced pressures such as fishing and pollution

      • For example, the Galápagos Marine Reserve protects unique species found nowhere else in the world

      • It does this by imposing fishing restrictions and carefully managing tourism

Support for aquatic food chains

  • Spawning and nursery grounds:

    • MPAs provide safe areas for fish and other marine organisms to reproduce and for juveniles to grow

  • Feeding grounds:

    • By protecting areas rich in food sources, MPAs ensure that marine species have access to enough food

Spillover effect

  • Population growth beyond MPA boundaries:

    • Healthy and abundant populations within MPAs can migrate to nearby areas

    • This replenishes fish stocks and benefits fisheries outside the protected zones

  • Genetic diversity:

    • MPAs maintain genetic diversity by protecting breeding populations

    • This contributes to the resilience of marine species

      • For example, the Chagos Marine Reserve in the Indian Ocean supports genetically diverse populations of fish and coral

Sustainable yields

  • Fisheries management:

    • MPAs can help maintain sustainable fishery yields by preventing overfishing and allowing fish populations to recover

    • Sustainable fish populations lead to more stable and long-term economic benefits for fishing communities

Examiner Tips and Tricks

You should familiarise yourself with at least one specific example of an MPA and its impacts on marine life and local communities—a few examples you could focus on include:

  • Great Barrier Reef Marine Park (Australia)

  • Papahānaumokuākea Marine National Monument (Hawaii)

  • Galápagos Marine Reserve (Ecuador)

  • Chagos Marine Reserve (British Indian Ocean Territory)

  • Monterey Bay National Marine Sanctuary (United States)

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Alistair Marjot

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