What’s going on here?
The UK wants to extend its ban on bottom trawling to include a further 41 Marine Protected Areas in English waters covering an area of 30,000km2.
Bottom trawling is a particularly destructive fishing method where a cone-shaped net is dragged through the ocean, while maintaining constant contact with the seabed. The largest bottom trawlers can travel across nearly 600 square miles of seabed in one trawl, an area the size of London. And they leave a trail of degradation and damage in their wake.
What does this mean?
A ban would prevent trawling in vulnerable marine ecosystems. With bottom trawling, everything goes into the net. Environmentally, this is bad because it has significant amounts of bycatch which are species caught unintentionally, killed and discarded. For example, in the North Pacific, around 40 tonnes of cold-water corals are unintentionally caught by bottom trawlers each year. It also damages the ecosystem of the seabed which in some cases is irreversible.
Atwood et al 2024 also found that when trawl nets scrape against the seabed, they disturb the carbon stored in marine sediments. This can release plumes of carbon-rich particles, reducing the oceans’ capacity to absorb carbon dioxide and contributing to ocean acidification.
Currently only 38 of the UK’s 377 marine protected areas are legally protected from this destructive practice. Previously, the Government has sought to place restrictions in areas with certain features such as reefs. However, small scale and patchy bans have minimal environmental benefits, according to Oceana.
We do know that complete bans of bottom trawling works. Lyme Bay, an area in the south of England, saw a 95% increase in abundance of marine life following a complete ban. Other countries across the world have created similar bans to protect natural resources in all their waters, including a total ban in Belize and Hong Kong.
Why should we care?
Banning bottom trawling would help the UK meet the 30×30 initiative to stop biodiversity loss. It’s part of the UN Global Biodiversity Framework agreed by nearly 200 countries to protect 30% of land and sea by 2030, support action on climate change and keep vital ecosystems healthy.
Banning bottom trawling allows ecosystems to recover which in turn benefits small-scale fishing communities. BalticSea2020 found that in Öresund, a protected stretch of water between Sweden and Denmark, the price of cod was double that in areas nearby without a ban, because the fish were so much bigger.
There is also the potential carbon emissions saving, from reduced disturbance to marine sediment on the seabed, which in turn would mean reduced carbon in the ocean. This would be beneficial for the marine environment and for the people who depend on it.
Be Curious!
- Read the Fauna & Flora article on Bottom Trawling and its impacts
- Watch Ocean with David Attenborough which highlights the impacts of destructive fishing methods like bottom trawling
- Become a wavemaker and get action alerts from OceanaUK
Featured image by @jannerboy62, via Unsplash
