How a global movement is taking on bottom trawling, one of the most contentious ocean issues

by Tom Collinson, Senior of Advocacy Officer (he/him), Blue Ventures

The world of commercial fishing is not new to controversy and conflict. Disagreements over where people can fish and what they can catch stretch back centuries. 

From the Cod Wars to Brexit, to the Palac Strait and to the South China sea, fights over fish have had a marked effect on our geopolitical, socio-economic and environmental landscapes. 

But the source of one of today’s most contentious fishing controversies doesn’t derive solely from who gets to catch fish, but what methods they use to catch them.  

The place of bottom trawling – the practice of dragging a weighted net across the seabed to catch fish – in the world’s commercial fisheries has been debated for generations. As early as the 13th and 14th centuries, sail-powered bottom trawlers were criticised for the destruction they wrought on seabed habitats, their tendency to indiscriminately catch juvenile fish, and the subsequent impacts they had on other fishing sectors. 

photo credit Sarah Foster/Project Seahorse

The dissent against bottom trawling continued into the 20th century. In Scotland, the public outcry led to a ban on the practice in waters close to shore. Decades later, the repeal of this ban revived old debates and sparked a national movement among coastal communities. 

But despite these criticisms, bottom trawling has grown into a globally ubiquitous fishing practice embraced by coastal nations due to its startling efficiency. Bottom trawlers propelled by powerful engines and dragging nets the size of double-decker busses can scoop up tonnes of fish and other sea creatures in a matter of hours; catching such volumes and diversities of marine life is impossible using other methods. 


The Transform Bottom Trawling Coalition

In recent months, 50 organisations have united around a shared vision for the future for our oceans in which bottom trawling – arguably the most prevalent, controversial and environmentally damaging of global fishing practices – is radically scaled back by all coastal nations to safeguard fisheries, ecosystems and carbon stores. 

The Transform Bottom Trawling Coalition, which launched in September 2021, is calling on states, in consultation with fishworker organisations and other stakeholders, to:
1. Establish, expand and strengthen national inshore exclusion zones (IEZs) in which bottom trawling is prohibited and small-scale fishers are given preferential access. 
2. Prohibit bottom trawling in all marine protected areas (outside IEZs) to ensure vulnerable habitats and ecosystems are effectively protected and recovered. 
3. End subsidised bottom trawling and allocate financial and technical resources to support a fair transition for fleets. 
4. Prohibit the expansion of bottom trawling to new, untrawled areas.

Formed of small-scale fishers’ and fishworkers’ collectives, locally-based organisations, and environmental NGOs, the coalition is pro small-scale fishing, pro environment and dedicated to bringing the needs of coastal communities to the fore. 

Today, bottom trawlers catch over a quarter of all the world’s seafood. In 2016, the last year for which data are available, this equated to over 30 million tonnes and is more than any other fishing method. The industry provides direct employment for hundreds of thousands of fishers and food for millions. 

As the scale of bottom trawling has expanded steadily across the globe, so too have its impacts. A recent report identified bottom trawling as the single greatest cause of human-driven disturbance of the world’s seabed ecosystems and found that it is the only  fishing method linked to all three forms of marine biodiversity impact: overfishing, bycatch and seabed contact. 

Over the past 65 years alone, bottom trawlers have discarded overboard more than 400 million tonnes of untargeted marine life. This includes everything from protected species and marine megafauna to commercially valuable fish targeted and relied upon by small-scale fishers. 

photo credit Sarah Foster/Project Seahorse

The vast scale of bottom trawling discards and the unparalleled impacts trawling has on seabed ecosystems has led to conflict with small-scale fishers, who often target the same fish and share fishing grounds with trawlers. In the tropics, where trawlers fishing close to shore frequently come into contact with small-scale fishers, discards and habitat destruction directly impact the tens of millions of coastal people that rely on fishing for their livelihood and food security. Boats dragging trawl nets may also damage static fishing gear, such as pots and traps, used by small-scale fishers. The food security of coastal communities in wealthier countries is not as acutely affected by bottom trawling, but competition with trawlers and diminishing catches does affect fishers’ bottom line. 

photo credit Sarah Foster/Project Seahorse

Recently, scientists have warned of the potentially vast contribution that bottom trawling makes to global greenhouse gas emissions, adding a new dimension to bottom trawling debates. A 2017 study showed that bottom-trawl fisheries emit almost three times more greenhouse gases than non-trawling fisheries, and that bottom trawling may release millions of tonnes of carbon stored in seabed sediments.

These impacts demonstrate that bottom trawling is a special case. No other method of fishing causes such pervasive damage to our seas. No other method of fishing is as incompatible with the path to net zero. For the planet, for the ocean and for the hundreds of millions of people who depend upon it to eat and to live, we need to drastically transform bottom trawling now.

Rising up against bottom trawling 

The Transform Bottom Trawling Coalition is working to identify constructive, evidence-based solutions for bottom trawling aligned with its collective calls to action. These solutions will reflect the need for drastic and urgent reconsideration of current management approaches to bottom trawling to safeguard coastal fisheries and ecosystems. Recognising the broader context and importance of bottom trawling, the coalition will also engage with fleets to explore alternative methods and facilitate a just transition.

Forging a collaboration with RISE UP has brought new opportunities for the coalition to achieve shared goals of restoring ocean life, building a low carbon future, transitioning to a sustinable coastal economy and empowering and supporting coastal people. 

If you’d like to be a part of the global movement to transform bottom trawling, you can sign up at or by contacting

This is a guest blog and may not necessarily represent the views of other RISE UP network members or RISE UP as a whole. It is only through open dialogue and a diversity of ideas that we will arrive at the solutions necessary to restore Ocean health.

Posted on Categories News Updates
Date Published: 21st March 2022