A first-of-its-kind study in the Irish Sea is addressing critical evidence gaps around the environmental impact of bottom trawling on seabed carbon storage and its potential implications for climate change.
Bottom trawling – the practice of dragging nets along the seabed for fishing – has long been known to disturb carbon stored in the seabed, but scientists do not fully understand how these changes affect the environment.
The SeaSTORE project is providing a unique opportunity for scientists working with the fishing industry to measure carbon in the water column and sediment during active, real-world fishing activity, helping researchers understand how disturbed carbon moves through water and how much carbon may be released into the atmosphere.
While previous research has suggested that bottom trawling may have a significant impact on the release of planet-heating carbon dioxide (CO2), it is unclear how much carbon from the seabed reaches the atmosphere in practice.
"Fisheries provide a quarter of the world's seafood, and food production has to stay part of the conversation. Our aim isn't to argue for or against trawling, but to make sure that trade-offs between food production and seabed carbon can be considered in policy decisions." Professor Jan Geert Hiddink Project Lead for SeaSTORE, from Bangor University
Scientists from across the UK have travelled to the Irish Sea to study the impact of activity by three professional fishing trawlers, using novel techniques to track carbon. The ability to analyse the impact of real-world activity immediately after it has taken place, with the research ship following directly behind the trawlers, has been made possible through a unique collaboration between SeaSTORE and the fishing industry.
The research cruise in the Irish Sea, which began on 22 July and ended on 15 August, followed an earlier cruise in the winter. Together, the two research trips will help researchers to understand the impact of bottom trawling in different weather and seasonal conditions.
SeaSTORE, which has been funded by the Natural Environment Research Council, is led by Bangor University, in collaboration with Imperial College London, the University of Leeds, Heriot-Watt University, the Plymouth Marine Laboratory and the Centre for Environment, Fisheries and Aquaculture Science (Cefas).
Professor Jan Geert Hiddink, Project Lead for SeaSTORE, from Bangor University, said: "Bottom trawling is the most extensive physical disturbance to seabed carbon stocks on the planet, yet we don't know whether it turns sediments into a net source of CO2, by how much, or where and when. This project aims to close that gap with direct measurement across contrasting environments.
"What's missing is a holistic assessment. Previous work has looked at sediment carbon, water column processes, or air-sea exchange in isolation. We're bringing all of that together for the first time, from the seabed to the atmosphere.
"Fisheries provide a quarter of the world's seafood, and food production has to stay part of the conversation. Our aim isn't to argue for or against trawling, but to make sure that trade-offs between food production and seabed carbon can be considered in policy decisions."
