Close
Blue Marine’s mission is to ensure the effective protection of at least 30 per cent of the ocean by 2030 and the sustainable management of the whole ocean, support the livelihoods of coastal communities and recover marine biodiversity. As part of this mission, we aim to remove bottom-towed fishing (dredging and bottom trawling) from Marine Protected Areas (MPAs). It is well recognised that a reduction in bottom towed fishing in inshore waters will improve ecosystems which play a key role in climate regulation, biodiversity and well-being1,2.
With importance often being assigned by decision makers to delivering economically viable policies and plans, quantification of the value of ecosystems to society provides the evidence needed to inform the inclusion of environmental protection in decision making. Ecosystem service quantification and valuation is used to both incentivise protection and to help highlight and integrate non-market values into decision making
In 2024, Blue Marine commissioned a report by economics consultancy eftect to examine the potential uplift in ecosystem service benefits people could receive from inshore ecosystems when bottom-towed fishing has been removed. This was assessed through analysing the impacts on ecosystem services of protecting Scottish waters out to three nautical miles from the coast from bottom-towed fishing. Such a restriction would increase the seabed area fully protected from bottom towed fishing within the 3nm, by 86% (protecting an additional 26,489km2).
The results of the analysis showed that the total net monetary benefits increased approximately five-fold in present value terms over 20 years from -£914 million in BAU to £3.6 billion in the Protection Scenario). The study also acknowledged the associated costs of such a closure, but the results indicate that the expected loss in income from bottom-towed fishing would be offset by the recovery of marine habitats to provide other ecosystem services of significant benefit to society in Scotland (e.g. nature-based tourism) and globally (e.g. carbon sequestration).
The three nautical miles area was chosen for assessment due to a previous closure of this extent from 1886–1984. Those restrictions were implemented following fishermen’s concerns about the emergence and impact of bottom-towed fishing on the marine environment and fish stocks. Landings data and historical accounts indicate that the closure to bottom-towed fishing helped marine ecosystems to recover and maintain their productivity 3.
Figure 1 – The Scottish 3nm area and areas currently closed to bottom-towed fishing within this
Following sustained pressure from the bottom-towed fishing industry, the closure was repealed in 1984. Today, bottom trawling is allowed in over 90 per cent of Scotland’s inshore (0-12nm)) waters and dredging in 95 per cent. Since 1984, inshore fish stocks have plummeted4. This decline has also been seen in the number of active fishermen, the latest Scottish Sea Fisheries Statistics revealed that 326 jobs on fishing vessels were lost between 2022 and 20235 with a similar trend in the decline in the number of fishing vessels6.
Many countries have chosen to protect their immediate inshore waters where the most diverse and complex habitats are generally situated. Portugal, Denmark, Norway, Sweden and Peru have all introduced a coastal limit on bottom trawling. However, in Scotland over 72 per cent of the 3 nautical mile area is impacted by bottom towed fishing, threatening the ecosystems and vital ecosystems services these areas provide.
How we did it
To assess the ecosystem services provided by the habitats within Scotland’s inshore waters out to 3nm, the study analysed the services under two scenarios: a ‘business as usual’ (BAU) scenario, which assumed the continuation of current fishing activities and no major changes in marine management, and a ‘protection’ scenario, which assumed a closure of the area to bottom-towed fishing, with no other major changes to marine management.
Multiple datasets were analysed to get the best available estimate for benthic habitat type and extent, fishing effort and annual landings from within the area.
A natural capital approach was used which distinguishes between the stocks and flows of natural capital; projecting benefits into the future; and linking the provision of benefits to the size and health of the natural assets such as habitats, fish stocks. This is a widely used approach in policy making and aims to ensure that interventions and decisions prioritise maintenance of the assets to sustain multiple benefits, and not to maximise one of the benefits such as income for one sector at the expense of others. This research used approaches consistent with UK and Scottish government guidance, reflecting information on natural capital assets and their provision of ecosystem services.
Asset register
The report includes an asset register which details habitat areas within 3nm at the finest resolution possible with available evidence. This was key to identifying the significance of closing the 3nm area to bottom-towed fishing and identifying material ecosystem services and benefits for inclusion in the assessment.
Results
The study found that there would be multiple and significant environmental and socio-economic benefits from a closure removing bottom towed fishing within the 3nm zone, increasing the area fully protected from bottom-towed fishing from 4,300 km2 to 30,800 km2.
Environmental benefits:
- 257% increase in habitat area in the 3nm area receiving protection relative to the BAU – supporting gamete dispersal and pest and disease control.
- 103% increase in vegetated habitat (e.g. seaweed and kelp) areas receiving protection that can support additional carbon sequestration benefits
- 60% increase in biogenic habitat areas protected – supporting regulating services (e.g., water quality and flood protection) and cultural services (e.g., nature-based tourism, health and well-being).
- 94% increase in seaweed and kelp areas protected supporting wild harvesting and aquaculture.
Socio economic benefits
- Five-fold increase in total net monetary benefits in present value terms over 20 years from –£914 million in BAU to £3.6 billion in the Protection Scenario.
- Potential 52% increase in static gear fish landings from areas previously under pressure from bottom-towed fishing.
- Double the estimated net carbon sequestration within the 3nm area (i.e. carbon sequestered by subtidal habitats and net of emissions from sediment disturbance), due to the recovery of subtidal sediments.
Conclusions and next steps
The results from this study highlight the benefits to the environment, society and local economies of protecting Scotland’s inshore waters from bottom towed fishing.
It is acknowledged that exclusion of bottom towed fishing from inshore waters could result in socio-economic impacts on certain sectors of the fishing industry. Blue Marine is advocating for a just transition away from damaging fishing practices to enable communities and livelihoods to thrive alongside restored seas. In 2024 to assess the social, economic and environmental impacts associated with transitioning away from bottom towed fishing practices. The framework can be applied during the development of future fishery management and Impact Assessments to allow informed management of fisheries and provide a fair and equitable route to transition away from destructive activities. Blue Marine developed a Just Transition Analysis Framework to assess the social, economic and environmental impacts associated with transitioning away from bottom towed fishing practices. The framework can be applied during the development of future fishery management and Impact Assessments to allow informed management of fisheries and provide a fair and equitable route to transition away from destructive activities.
Scotland’s seas are a public asset and should be managed in a way that maximises the public benefits of these public resources. The Scottish Government committed to protect inshore seabeds by March 2024 and yet there has been no progress.
Blue Marine is a member of OurSeas, an alliance of over 150 coastal businesses, community groups, fishermen’s associations and environmental organisations campaigning for the recovery of Scotland’s coastal marine environment and the revival of sustainable inshore fisheries. One of the coalition’s main aims is for the re-establishment of a coastal limit on bottom-towed fishing to restrict the use of damaging fishing gear from the inshore zones of Scotland’s seas that are most vulnerable.
Scottish Minsters must act now to deliver management of bottom towed fishing in inshore waters and significantly reduce its impacts if Scotland is to address the joint crises of biodiversity loss and climate change.
We must act now – please sign the Our Seas coalition petition that calls on the Scottish government to stop the destruction of the country’s seabed by reinstating a coastal limit on bottom-trawl and dredge fishing.
To see the full report, results and recommendations, please click here.
