Bycatch of dolphins and porpoises, as recently highlighted by the vital monitoring efforts of the Cornwall Wildlife Trust, continues to occur in the waters off the southwest of England. As well as affecting the welfare of individual animals and the resilience of their populations, this bycatch has a human cost: fishermen can find the experience of a dolphin or porpoise caught in their gear incredibly distressing.
Cornish fishermen had already been working to reduce bycatch for several years when Clean Catch was established in early 2020. Since then, the programme has been collaborating with the fishing industry, scientists, NGOs, and other key groups in both the Southwest and beyond to improve knowledge and methods for monitoring and mitigating bycatch of a range of sensitive marine species. We are funded by Defra, with our work informing bycatch policy including the UK Government’s Marine Wildlife Bycatch Mitigation Initiative.
What we’re doing
- Trialling pingers for dolphins and porpoises – With a group of skippers, we’re testing the efficacy of pingers to minimise bycatch of dolphins and porpoises in Cornwall’s inshore gillnet fishery by emitting sounds which keep them away from gillnets. Results from our trial will be published in due course. There is already strong evidence from fisheries elsewhere in the world that pingers – already mandatory for over-12 metre vessels – can significantly reduce bycatch of small cetaceans, although as with any type of bycatch mitigation device, efficacy can be context-dependent.
- Developing and testing a prototype ‘Passive Acoustic Reflector’ (PAR) – Our PAR is designed to passively reflect back echolocations from dolphins and porpoises, with the aim of alerting them to nets. The potential extra benefits of PARs compared to pingers is that they don’t require batteries, can fit seamlessly into fishing operations by being placed like floats on nets, and don’t risk becoming another source of noise pollution in the marine environment. Our PAR has undergone robustness testing off Cornwall and, as of February 2026, a week of at-sea testing in Germany in collaboration with the Thünen Institute.
- Acoustic monitoring of dolphins and porpoises – We currently have several acoustic monitoring devices deployed off South Cornwall, which are recording detections of echolocation clicks by dolphins and porpoises. This will improve our knowledge of when and where these animals are likely to be present over the day and over different months and seasons, with the aim of using the data to help identify when and where to target bycatch reduction measures.
- Gathering research data on bycatch with the Clean Catch self-reporting app – Our voluntary app is designed to be a convenient way for fishermen nationwide to log their catches and any bycatch or other interactions with sensitive species like seals. Through the app they can see a history of their catches and get live updates on any bycatch hotspots in their area, while the data they contribute can play a valuable role in bycatch research. (Note: Fishermen are still legally obligated to report bycatch of any marine mammal to the MMO and of sharks, skates, and rays in their logbooks.)
- Complementing self-reporting by fishermen with Remote Electronic Monitoring (REM) – Fishermen involved in our pinger trial have REM systems installed to support and validate the information they provide. We’ve also just installed REM on the trawler vessels involved in our new seabird bycatch trial taking place in partnership with the Eastern England Fish Producers’ Organisation (EEFPO) in the northeast; more on that below! REM is a powerful tool for sustainable fisheries management, but our experience is that it is best used as part of a mosaic of strategies.
- Conducting the monitoring phase of a seabird bycatch mitigation trial in the North Sea whitefish fishery – We’ve teamed up with the EEFPO who responded to our call-out to help set up a second bycatch monitoring and mitigation trial in England. This trial focuses on seabirds, and we are currently gathering baseline data via REM, self-reporting by skippers, and trips by observers from the Bycatch Monitoring Programme. The next step will be to commence the mitigation phase of the trial.
- Identifying bycatch hotspots – We’re combining predictive modelling with a review of existing evidence to fine-tune our understanding of the where and when of bycatch hotspots in UK waters. This will help prioritise future monitoring and mitigation efforts, working with affected fisheries. Results are due shortly.
- Learning more from fishermen about barriers to reporting bycatch – While all UK fishermen are legally obligated to report bycatch of cetaceans to the MMO and of sharks, skates, and rays in their logbooks, there’s awareness that multiple barriers to doing so exist. We are carrying out research with fishermen to dive into the details of this and what changes could be made.
How collaboration is the heart of all our work
Clean Catch is formed of the fishing industry, scientists, eNGOs, technology developers, communicators, policymakers, and other people and organisations who all have a role to play in monitoring and mitigating the bycatch of sensitive species in UK waters. But fishermen themselves are the heart and the engine, lending their expertise, insights, and enthusiasm to all our collaborative efforts. Our trials are guided by the principle of continuous co-design, with fishermen empowered to provide feedback or raise any concerns whenever they wish and the Clean Catch team able to action this in response. Simply, for bycatch monitoring and mitigation to be effective and long-lasting, it must be feasible for fishermen – and they know best how to achieve this.
As one example, we’ve directly incorporated suggestions from skippers into the Clean Catch self-reporting app, creating new easier-to-use options within the interface and expanding the app to enable fishermen to report different types of interactions with seals.
Clean Catch also benefits hugely from the expertise and passion of members of our National Advisory Board, Cornwall Local Focus Group, and ad-hoc Expert Working Groups. These groups together represent a diversity of sectors, geographies, disciplines, and species focuses from across the UK. Our underpinning governance framework is designed to be equitable, transparent, and effective in drawing on this collective capability.
We fit within a wider “ecosystem” of action on bycatch
We don’t work in isolation. In the Southwest specifically, alongside the work of the Cornwall Wildlife Trust to monitor strandings of dolphins and porpoises and collect data on other sensitive marine species, other initiatives are underway. The EU LIFE-funded CIBBRiNA, which works across Europe to minimise bycatch of sensitive species, is collaborating with static net fishermen off Cornwall to also test pingers and another type of passive acoustic reflector, and to deploy hydrophones and 3D tracking systems to study the behaviour of dolphins and porpoises around nets. As for seabirds, Fishtek Marine, Cornwall IFCA, and fishermen have been trialling several ‘above water deterrents’ including the Looming-eyes Buoy and the Scarybird.
Up in the northeast, our new trial in partnership with the EEFPO taps into an existing network of engaged individuals and fisheries. The Scottish longline hake fishery is already trialling ‘bird scaring lines’ with the involvement of fishing company Hooktone Group Ltd, the Aberdeen Fish Producers’ Organisation, and the University of St Andrews (and, more recently, CIBBRiNA again). These organisations, as well as the North Sea Fishermen’s Organisation, met with us just two weeks ago for the first meeting of a new Expert Working Group to share knowledge and advice on implementing seabird bycatch mitigation measures.
Bycatch of sensitive marine species in commercial fisheries is a complex challenge. There is no single solution – but there are multiple ways to work together.
Want to know more and find out how you can be involved? Contact us at secretariat@cleancatchuk.com.