Report on the Environmental Impact of Bottom Trawling and its Conflict with Sustainable Development Goals

Introduction: An Obstacle to Sustainable Development

Industrial bottom trawling, a widespread fishing method involving dragging heavy nets across the seafloor, presents a significant challenge to the achievement of the United Nations Sustainable Development Goals (SDGs). This practice, which scrapes an area of seabed equivalent to a football field every second, not only impacts marine ecosystems but also undermines global efforts related to climate action, responsible consumption, and sustainable livelihoods. This report analyzes the multifaceted damage caused by bottom trawling and frames it within the context of the 2030 Agenda for Sustainable Development.

Environmental and Climatic Impacts: A Direct Threat to SDG 13 and SDG 14

The environmental consequences of bottom trawling are severe and often irreversible, directly contravening the objectives of SDG 14 (Life Below Water) and SDG 13 (Climate Action).

Undermining SDG 14: Life Below Water

Bottom trawling systematically degrades marine habitats, a critical issue for SDG Target 14.2, which calls for the sustainable management and protection of marine and coastal ecosystems. The practice leads to:

• Habitat Destruction: A single pass of a trawl net can destroy ancient and fragile ecosystems like coral reefs and sponge fields, converting biodiverse habitats into barren wastelands. This is particularly evident in areas like the North Sea and the Atlantic.
• Biodiversity Loss and Bycatch: The method is notoriously unselective. In some European waters, non-target species (bycatch) constitute up to 92% of the haul. This indiscriminate capture of sharks, sea turtles, corals, and other marine life severely disrupts food webs and threatens biodiversity, working against SDG Target 14.4 (end destructive fishing practices).

A Threat to SDG 13: Climate Action

Recent scientific findings reveal that bottom trawling is a significant, yet often overlooked, contributor to climate change. The practice disturbs carbon-rich marine sediments, releasing an estimated 370 million metric tonnes of carbon dioxide annually—an amount comparable to the entire aviation industry. This process directly undermines SDG 13 (Climate Action) in two ways:

• Atmospheric Carbon Release: Studies indicate that 55-60% of the disturbed CO2 enters the atmosphere, contributing to global warming.
• Ocean Acidification: The remaining 40-45% of released carbon is absorbed by the ocean, exacerbating ocean acidification and further damaging marine ecosystems already under stress.

Global Status and Regulatory Landscape

Despite its destructive nature, bottom trawling accounts for approximately 25% of the global fish catch. Regulation and enforcement vary significantly across regions, highlighting inconsistencies in the global commitment to SDG 14.

Regional Analysis of Regulatory Enforcement

• United States: Has prohibited bottom trawling in over half of its federal waters, particularly along the West Coast, to protect vital fish habitats.
• Asia: China, Vietnam, and Indonesia are responsible for a significant portion of the global catch. While regulations exist, weak enforcement, particularly in the high seas and disputed waters like the South China Sea, leads to widespread illegal, unreported, and unregulated (IUU) fishing.
• Africa: Nations like Ghana and Nigeria face challenges from foreign trawlers circumventing local laws. In response to declining fish stocks, Ghana has announced a future ban on all industrial fishing, a decisive step towards SDG 14.
• Europe: The EU has mandated a phase-out of bottom trawling in all Marine Protected Areas (MPAs) by 2030. However, enforcement is weak, with an estimated 86% of the Natura 2000 network’s marine habitats still affected. Subsidies for bottom trawling continue in several countries, including Norway, Italy, and Denmark, directly contradicting SDG Target 14.6 (prohibit harmful fisheries subsidies).
• New Zealand: The practice is heavily regulated, with the government claiming world leadership in managing its effects by closing large marine areas to trawling.

Socio-Economic Drivers and Barriers to Reform

The persistence of bottom trawling is driven by economic inertia, powerful lobbying, and government subsidies, creating complex challenges for SDG 8 (Decent Work and Economic Growth) and SDG 12 (Responsible Consumption and Production).

Economic Inertia and Subsidies vs. SDG 14.6

Bottom trawling is profitable in the short term, and its continuation is heavily supported by government subsidies. The EU, for example, provides an estimated €1.3 billion in annual subsidies to industrial fishing. This financial support creates a direct conflict with SDG Target 14.6, which calls for the elimination of subsidies that contribute to overcapacity and overfishing. The practice costs European society an estimated €330 million to €11 billion annually, primarily from the social cost of its carbon emissions.

Public Opposition and Industry Resistance

While the fishing lobby strongly opposes bans, citing economic hardship for fishermen, public sentiment is shifting. In the UK and across Europe, polls show overwhelming public support (73-80%) for banning bottom trawling in MPAs. This growing awareness, catalyzed by documentaries like David Attenborough’s Ocean, signals a public demand for alignment with SDG 12, which promotes sustainable production patterns.

The Path Forward: Aligning Fisheries with the 2030 Agenda

Achieving SDG 14 and related goals requires a decisive shift away from destructive practices. Marine ecosystems have demonstrated resilience and the capacity for recovery in areas where trawling is prohibited. The following actions are critical:

1. Enforce Bans in Marine Protected Areas: Implement and enforce total bans on bottom trawling within all designated MPAs to fulfill the objective of SDG Target 14.5 (conserve at least 10% of coastal and marine areas).
2. Reform Subsidies: Redirect financial support from destructive industrial fishing towards sustainable alternatives like pole-and-line or trap-based systems, in line with SDG Target 14.6.
3. Enhance Supply Chain Transparency: Empower consumers to make informed choices that support SDG 12 by mandating clear labeling on how seafood was caught.
4. Strengthen Monitoring and Enforcement: Invest in surveillance technologies, such as satellite tracking and onboard cameras, to ensure compliance with regulations.
5. Bolster International Cooperation: Strengthen international treaties and the authority of Regional Fisheries Management Organizations (RFMOs) to govern the high seas, advancing SDG 17 (Partnerships for the Goals).

Conclusion: An Urgent Call for Action

Bottom trawling is an environmental crisis sustained by outdated economic models and a lack of political will. It fundamentally undermines the interconnected goals of protecting life below water (SDG 14), taking climate action (SDG 13), and ensuring responsible consumption and production (SDG 12). As public awareness grows and the scientific evidence of its harm becomes undeniable, the international community faces a clear choice. By implementing targeted bans, reforming subsidies, and fostering transparency, it is possible to reverse the damage and allow marine ecosystems to recover. The health of the ocean is not a foregone conclusion; it is a direct result of the policies and practices we choose to support.

SDGs Addressed in the Article

1. SDG 14: Life Below Water

   • The entire article is centered on the destructive impacts of bottom trawling on marine ecosystems. It directly addresses the conservation and sustainable use of oceans, seas, and marine resources. Specific issues mentioned include the destruction of seabed habitats like coral reefs and sponge fields, the loss of ocean biodiversity through high levels of bycatch, the decline of fish stocks, and the overall degradation of marine environments into “lifeless wastelands.”

2. SDG 13: Climate Action

   • The article establishes a direct link between bottom trawling and climate change. It highlights a study finding that the practice releases “up to 370 million metric tonnes” of carbon dioxide annually by disturbing carbon stores in seafloor sediments. It also notes that a portion of this CO2 remains in the ocean, “worsening ocean acidification.” This connects the fishing practice to global climate regulation and its disruption.

3. SDG 12: Responsible Consumption and Production

   • The article discusses the economic drivers and supply chain issues related to bottom trawling. It points to government subsidies that support this destructive practice, the need for transparency so “consumers should be informed of how their fish was caught,” and the promotion of sustainable alternatives like “pole-and-line fishing.” This relates to shifting towards sustainable production patterns in the fishing industry.

4. SDG 16: Peace, Justice and Strong Institutions

   • The article repeatedly points to failures in governance and regulation. It mentions “political inaction,” “weak enforcement” of bans in places like the EU and China, widespread “illegal, unreported, and unregulated (IUU) fishing” by fleets from Vietnam, and the inability of Regional Fisheries Management Organizations (RFMOs) to regulate the high seas effectively. The call to “expand international treaties” and “invest in surveillance technologies” directly addresses the need for stronger institutions.

5. SDG 2: Zero Hunger

   • The article notes that “seafood is a staple food for billions of people” and that bottom trawling contributes to the “decline of small pelagic fish” and “declining fish stocks.” By threatening the sustainability of fish populations, this practice jeopardizes a critical food source for a large portion of the global population, connecting it to the goal of achieving food security.

Specific SDG Targets Identified

1. Target 14.2: Sustainably manage and protect marine and coastal ecosystems

   • The article’s core focus is on the destruction of seabed habitats (“razes coral reefs, suffocates ocean biodiversity”) and the need to protect them. The discussion around banning bottom trawling in Marine Protected Areas (MPAs) in the EU and the UK is a direct effort to achieve this target. The mention of ecosystem recovery in Alaska and Scotland where trawling is banned demonstrates the potential for restoration.

2. Target 14.4: End overfishing, illegal, unreported and unregulated (IUU) fishing and destructive fishing practices

   • Bottom trawling is explicitly identified as “one of the most environmentally harmful fishing techniques ever developed” and a “destructive fishing practice.” The article details issues of IUU fishing, particularly mentioning Vietnamese fleets in the South China Sea and Chinese trawlers in West Africa. Efforts by countries like Indonesia to destroy illegal boats and Ghana’s plan to ban the practice are actions toward this target.

3. Target 14.5: Conserve at least 10 per cent of coastal and marine areas

   • The article extensively discusses Marine Protected Areas (MPAs). It criticizes the lack of actual protection, stating that in the UK “only 38 out of 377 MPAs… are safe from bottom trawling” and that “destructive fishing… affects 86% of the area” of the EU’s Natura 2000 marine sites. Proposals to extend bans across more MPAs in the UK directly relate to making these conserved areas effective.

4. Target 14.6: Prohibit fisheries subsidies that contribute to overfishing

   • The article identifies government subsidies as a key reason the practice continues, stating, “The European Union spends an estimated 1.3 billion euro (US$1.5 billion) on industrial fishing subsidies every year.” It explicitly recommends to “redirect subsidies away from destructive fishing practices” as a solution, directly aligning with the goal of this target.

5. Target 13.2: Integrate climate change measures into national policies

   • By identifying bottom trawling as a “hidden climate threat” that releases as much CO2 as the “whole aviation industry,” the article implies that this impact should be included in climate policies and regulations. The failure to regulate it is a failure to integrate a significant emissions source into climate action plans.

6. Target 12.8: Ensure people have the relevant information and awareness for sustainable development

   • The article emphasizes the role of public awareness, citing how David Attenborough’s documentary “has brought unprecedented attention to the destructive impact of bottom-trawling.” It also mentions the need for transparency in the seafood supply chain so consumers can make informed choices, which is central to this target.

Indicators for Measuring Progress

1. Area of Marine Protected Areas (MPAs) with an effective ban on bottom trawling

   • The article provides specific numbers that can be used as a baseline indicator. For example, it states that the UK government proposed extending its ban from “18,000km² to 48,000km².” Tracking the percentage of MPA territory where bottom trawling is prohibited versus the total designated MPA area would measure progress. The EU’s goal to “end bottom trawling activities across all marine protected areas by the decade’s end” is a measurable target.

2. Amount of CO2 emissions from seafloor disturbance

   • The article quantifies the annual emissions from bottom trawling as “up to 370 million metric tonnes every year.” This figure can be used as an indicator. Progress could be measured by tracking the reduction in these emissions as a result of policy changes and bans on the practice.

3. Value of subsidies directed to destructive fishing practices

   • The article provides a specific monetary value: “The European Union spends an estimated 1.3 billion euro (US$1.5 billion) on industrial fishing subsidies every year.” This can serve as a direct indicator. Progress would be measured by the reduction and redirection of these funds toward sustainable alternatives.

4. Proportion of bycatch in total catch

   • The article mentions that in some European waters, “up to 92% of the catch… does not comprise the target species.” This percentage of unintended victims, or bycatch, is a direct indicator of how destructive a fishing method is. A reduction in this percentage would signify a move towards more selective and sustainable fishing.

5. Level of public support for banning destructive practices

   • The article cites specific polling data as an indicator of public sentiment, such as “73% of Europeans support a ban on bottom trawling” and “80% of UK adults support banning bottom trawling in protected areas.” The number of petition signatories (“over 250,000 Europeans”) is another quantifiable measure of public awareness and demand for change.

6. Hours of illegal fishing activity in protected zones

   • The article provides a stark indicator of poor enforcement: “In 2024 alone, over 20,000 hours of trawling occurred in [UK] MPAs.” This metric directly measures the effectiveness of institutional controls and regulations. A decrease in these hours would indicate improved enforcement and progress towards protecting marine ecosystems.

SDGs, Targets, and Indicators Analysis

Source: earth.org