Newly published study on the effects of trawling and dredging across the world hits the headlines



michael Kaiser

Our Chief Scientist and Professor of Fisheries Conservation at Heriot-Watt University in Edinburgh, Michel Kaiser's newly published study on the effects of trawling and dredging across the world has been hitting the headlines in The Scotsman and The Herald

The health of our seas and oceans matters, not just from an environmental point of view but from an economic one. It is a threat that is increasingly being taken seriously. 

How can we ensure our seas and oceans thrive with fish, other animals and plantlife? The new research underlines the need to roll-out sustainable fisheries management.  There are examples of good practice, including here in Scotland, that can be learned from.

Professor Kaiser and a team of colleagues from institutions around the world looked at where trawling takes place and mapped this against the status of seabeds and the communities they support.  The analysis considered different habitats and various types of trawling gear.

It found that intensively trawled regions had low habitat status relative to others, the worst of which was the Adriatic. However, it also showed that when fisheries are managed sustainably, the wider environmental impacts are considerably lower. In the UK there are examples in Shetland, the Isle of Man and the English Channel of management plans which enable fish and shellfish stocks to be harvested sustainably. These plans promote less time at sea and less disturbance on the seabed as well as lower carbon emissions. 

This research advances understanding and enables better assessment of risks. The hope is that the study highlights regions needing more effective management to reduce exploitation, improve stock sustainability and seabed environmental status. With healthy seabeds, biodiversity can be protected and improved upon to address the nature crisis our world faces.

An important aspect of the study showed that high quality data is required to have a better understanding of local situations. Mapping trawl footprints requires precise information about where and when boats are in operation. In most countries this detailed data is not publicly available. 

The lack of high-resolution trawl effort data or, for confidentiality reasons, where it is kept private must be addressed. The benefits to public policy at national and international levels would be immense. Management plans could be co-designed with local fishing interests to help bring together environmental, commercial and community interests.

Bottom-trawl fisheries provide about a quarter of marine catch, making substantial contributions to global food supply and livelihoods. So, on one hand the environment must be protected but on the other coastal communities and human nutrition must be supported.

Professor Kaiser is due to speak on this topic at Expo 2020 Dubai. This is an urgent issue. Maintaining “life below water” is one of the UN's Sustainable Development Goals. By improving access to data, there is a better chance of developing specific local sustainable management plans to future-proof our fisheries. 

As part of Expo 2020, the UK Pavilion is hosting a What Will We Eat? summit where Professor Kaiser will participate in the How to Feed the World without Destroying the Planet panel session. He joins other distinguished experts, to examine the need to rethink how we grow, consume, and provide food for a sustainable future.

Taking place on Thursday 17 February 2022, 12:00 – 13:00 (UK – GMT) /16:00 – 17:00 (UAE – GST), to view the full agenda and register virtually, please click here.

Heriot-Watt University is supporting the UK Pavilion at Expo 2020 Dubai, showcasing its 200-year history of developing research and innovation that contributes to and drives forward solutions to global challenges.

Open until 31 March 2022, the postponed Expo 2020, is expected to attract 25 million visitors from across the world for a six-month celebration of creativity, innovation, humanity, and world cultures. 


Julie Fraser