Bottom trawling is costing Europe up to €11billion a year in both government subsidies and in carbon emissions released from disturbed seafloors, amounting to what has been likened to an economic and ecological catastrophe by those at National Geographic Pristine Seas, the team behind this groundbreaking new study.

Released this week, this is the first study of its kind to measure the full economic cost of bottom trawling in Europe’s waters – spanning the EU, the UK, Norway, and Iceland) highlighting that damage caused by this devastating fishing practice totals some €10.8bn a year in costs to society.

The study has found that while bottom trawling does support some jobs, provide some protein and bring in some revenue, these are in fact of minimal benefit to Europeans and concludes that the costs in supporting the bottom trawling industry far exceed the benefits.

The new research comes as a coalition of civil society organisations calls on governments across Europe and the UK to ban bottom trawling in the continent’s marine protected areas (MPAs) – spots that are meant to be safe havens for marine life. Currently, sixty percent of European MPAs are bottom trawled and 13% of the bottom trawling effort in Europe happens inside MPAs (20% for the EU).

“Bottom trawling in Europe is devastating marine life in more than half of the areas that are supposed to be protected by law. Bottom trawling in marine protected areas isn’t just an environmental aberration, it’s an economic failure,” said Enric Sala, National Geographic Explorer in Residence, founder of Pristine Seas, and one of the authors of the study. 

“Banning bottom trawling in MPAs would benefit ocean life, the climate, and even the fishing industry itself. It’s a win-win-win solution.”

There’s no escaping that bottom trawling is, simply, a destructive fishing method in which a net – some so large that they could hold ten 747 jets – is dragged along the seafloor to catch fish and other marine species, razing marine habitats and killing organisms along the way.

The practice is exceedingly wasteful, with up to 75% of the marine life getting caught in the nets and ultimately discarded.

Still, however, the practice persists, even in designated safe haven. In northern Europe, bottom trawling in Marine Protected Areas has lowered the abundance of vulnerable species such as sharks, rays, and skates – which are now less abundant inside MPAs than in unprotected waters nearby. 

“All told, bottom trawling imposes a net cost to European society of between €330 million and €11 billion annually, mostly due to the social costs of the enormous amount of carbon dioxide that is emitted from disturbing the seafloor sediment,” said Kat Millage, marine researcher for Pristine Seas and lead author on the study.

What’s more, European taxpayers are the ones funding the destruction of their own protected marine areas. European governments spend an estimated €1.3 billion annually on bottom trawling subsidies, a figure that is nearly equivalent to the value of the jobs the industry creates.

Without subsidies, bottom trawling in some countries would not even be profitable for the companies practicing it. Meanwhile, bottom trawling produces just 2% of the animal protein that Europe consumes.

Those offering the highest subsidies for bottom trawling include Italy, Norway, Denmark, Great Britain, and Sweden. The total value of the marine life brought onto land via bottom trawling is the highest in Norway, followed by Iceland, Great Britain, Italy, Spain, and the Netherlands. 

The findings of the study were landed on when researchers analysed bottom trawling efforts in European waters between 2016 and 2021, using data from Global Fishing Watch, which tracks real-time fishing activity worldwide using satellites. They then calculated the value of this fishing practice to European society as benefits (fishing revenue, protein supply, and jobs) minus costs (operating costs, discards, subsidies, and carbon emissions).

One of the key measures authors used is the social cost of carbon dioxide emissions, which provides an estimate of the economic damages stemming from the impacts of climate change, including sea level rise and declines in labour productivity and human health.

This study builds on recent research calculating the annual carbon dioxide emissions released from bottom trawling and the extent to which these emissions enter into the atmosphere.

One previous study – published in Nature – found that the annual carbon dioxide emissions released from bottom trawling are on the scale of the annual carbon dioxide emissions from global aviation. A second study – published in Frontiers in Marine Science – added that over half of the carbon dioxide produced underwater by bottom trawling will make it into the earth’s atmosphere within nine years.

The message of the study is a clear one: banning bottom trawling in MPAs – and not relocating that fishing effort elsewhere – would help restore Europe’s overfished seas, mitigate global warming and make European fishing more sustainable.

The new study finds that permanently reducing bottom trawling efforts across Europe by a third would maximise net benefits under a scenario where a tonne of carbon dioxide is valued at its minimum. Redirecting a fraction of current harmful subsidies would be enough to finance a fair transition for the fishing industry.

“Ending bottom trawling in Europe’s marine protected areas isn’t just good for the environment – it’s essential for saving billions in public costs,” said Sala. “This move will save taxpayers money, protect marine life, boost the fishing industry and help us tackle global warming.”

The costs and the benefits of bottom trawling do not operate on the same scale. While bottom trawling does create some jobs, it doesn’t generate as many as other fishing methods. Small-scale fisheries generate between three and four times more jobs than industrial bottom trawlers.

“My biggest issue with trawling is not that it is in and of itself unsustainable, as it’s capable of being managed far more sustainably than at present,” argued Bally Philp, national coordinator of the Scottish Creel Fishermen’s Federation.

“The issue arises in the all-too-common situation where trawling is taking place in locations where there’s alternative methods of fishing that can be more selective, support more employment, and have a lower environmental impact. Because by allowing trawling to take place in those areas, we are essentially forfeiting jobs, revenues, and our marine ecosystems unnecessarily and I really cannot understand why we would allow trawling under those circumstances.”

There is good news here, however. Some European leaders have already acknowledged the high cost of bottom trawling. In April last year, Greek Prime Minister Mitsotakis announced his commitment to ban bottom trawling in Greek MPAs by 2030; Sweden followed two months later.

The European Commission’s action plan calls for gradually phasing out bottom fishing in all MPAs by 2030.

“Bottom trawling is laying waste to the ocean life that provides jobs, food, and a liveable climate. As this research has confirmed, that is a great cost to society,” said Hugo Tagholm, executive director of Oceana UK.

“Small-scale, sustainable fishers seeing their livelihoods ripped away along with the reefs and seagrass meadows that are bulldozed by the weighted nets. And all this to line the pockets of a few.

“The truth is that thriving marine wildlife supports flourishing coastal communities. That is why Oceana and our NGO allies are coming together for a Week of Ocean Action to urge governments in the UK and across the EU to ban bottom trawling in marine protected areas once and for all.”

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