Eerie buzzing sounds and fleeting dolphin shapes marked a breakthrough moment for a tidal energy scheme off Anglesey. It was the first time sonar and audio equipment successfully combined with surface and underwater cameras to monitor marine mammals in real time using AI detection.
The sounds and images were gathered by the Marinus monitoring platform deployed by the Morlais project northwest of Anglesey’s Holy Island. The information it collected will be used to safeguard marine wildlife as Europe’s largest consented tidal energy development progresses.
This week the Marinus buoy was stood down and towed back to Holyhead after three years at sea. As well as tracking fish, dolphins and porpoises in the area, the unmanned platform has also been monitoring seabirds.
In July 2024, guillemots were fitted with miniature solar-powered transmitters on their legs. It followed concerns the Morlais scheme would devastate guillemots and razorbills at South Stack cliffs near Holyhead.
The work was carried out as part of the Marine Characterisation Research Project (MCRP) led by North Wales social enterprise, Menter Môn. Get the best island stories from our Anglesey newsletter – sent every Friday
A headline achievement for the Marinus buoy was a half-hour encounter with a dolphin late last year. As it followed a seven-month period of monitoring, Menter Môn Morlais said it “confirmed initial assessments that dolphins are relatively infrequent in this area”.
Scheme organisers said the work demonstrated that wildlife can be monitored effectively without disrupting their habitats and behaviour. They claimed it was a tick in the box for the sustainability of tidal energy schemes.
The Marinus monitoring platform returns to dock in Holyhead after completing its mission(Image: Menter Môn Morlais)
Helen Roberts, environment and compliance project manager at Menter Môn, said the project was a global first. She added: “The data we have gathered will help ensure that tidal energy devices within the Morlais zone can be deployed safely.
“From sonar and acoustic sensors to video and AI-driven monitoring, we have used technology not trialled elsewhere – and all as part of our commitment to protecting local marine wildlife.
“We’re now focused on the next phase and hope the tools and methodologies used at our site can be adapted for wider use, including in offshore wind and other industries looking to understand and reduce their impact on marine wildlife.”
Footage captured by Marinus was used to refine the system’s AI detection technology. It is hoped this technology, developed through a partnership between UK and US innovation teams, can now be prepared for commercial roll-out.
A dolphin off Anglesey is detected by AI-driven sonar and audio technology on board the unmanned Marinus monitoring platform(Image: Menter Môn Morlais)
All the data collected by the MCRP has been shared to the Crown Estate’s Marine Data Exchange. Menter Môn said the monitoring results will feed into discussions about the future of marine project consenting.
Working with a team of experts, Morlais is now developing a detailed Environmental Monitoring and Mitigation Plan (EMMP) to safeguard local marine wildlife as the scheme progresses.
In February, Morlais was awarded a further 18.5 MW capacity in the UK Government’s latest Contracts for Difference allocation. It brought the total secured for the scheme so far to 56.5MW.
Once built, Morlais has the potential to generate up to 240MW of clean low carbon electricity, enough to power more than 180,000 homes.
The first tidal energy devices are expected to be deployed in the Morlais zone from 2027. The North Wales Live Whatsapp community for top stories and breaking news is live now – here’s how to sign up