A new report published today aims to resolve key environmental concerns slowing the expansion of Scotland’s tidal stream energy sector. The study, Managing the Consenting Risk of Harbour Seal Collision in the Scottish Tidal Energy Industry, outlines recommendations to support project development while safeguarding harbour seals, whose populations have been declining in northern Scotland.
The report is part of the Tidal Industry Seal Project (TISP), funded by Crown Estate Scotland and Highlands and Islands Enterprise. It was produced with input from eight leading organisations in marine energy and environmental assessment.
Tidal stream energy is considered a reliable source of renewable power. Scotland’s Pentland Firth and Orkney Waters host some of the strongest tidal currents in the world and have produced more tidal energy than any other location globally. However, concerns about possible collisions between seals and tidal turbines have contributed to lengthy and complex consent processes for new projects.
Although monitoring to date has found no evidence of seal collisions, a precautionary approach remains standard due to the ongoing decline of harbour seals in the region. The report calls for science-led, proportionate regulation to enable responsible development without compromising environmental protections.
The tidal industry has established a regional developer group that is working with regulators and researchers to improve assessments of collision risk and explore better use of existing data, trial new monitoring technologies, and develop potential mitigation measures.
Dr. Ewan Edwards, Environmental Specialist at Xodus, said: “Harbour seal populations around Orkney and the north coast of Scotland have been in sharp decline for around 20 years. This is generally attributed to factors such as competition for food with other species, predation by killer whales or grey seals, and potentially biotoxins from algal blooms.
“Extensive monitoring of operational tidal projects in Scotland has found no evidence of seal-turbine collisions. On the contrary, data suggest that seals actively avoid operating turbines, especially during peak flows.
“The project team strongly believe that the weight of evidence suggests that collisions between harbour seals, or any other marine mammal, and tidal turbines are thankfully incredibly rare, and the risk of collision is a hypothetical one, rather than a realistic threat.”
Donald Leaver, Environment and Consents Manager at the European Marine Energy Centre (EMEC), added: “We recognise that for the tidal energy to grow, a collaborative effort is required to better understand whether the potential for seals to collide with turbines is an issue. Pioneering projects led by MeyGen, Nova Innovation and Orbital Marine Power have investigated this over several years and, so far, haven’t seen any evidence of seal-turbine collisions.
“With various new projects in the Pentland Firth and Orkney Waters due to be built out over the coming decade, supporting Scottish and UK government policy ambitions for energy security and climate resilience, it is vital this consenting uncertainty is resolved in a collaborative, science-led manner to enable sustainable development alongside the protection of our marine ecosystems.”
Fraser Johnson, Operations and Maintenance Manager at MeyGen, said: “We’re proud to have played a leading role in improving how we assess and manage environmental risks for tidal energy. This report demonstrates the significant progress the sector has made; however, to unlock its full potential, we must continue to work collaboratively, share our learnings, and maintain this momentum.
“At MeyGen, we’re committed to environmental stewardship but the consenting system must evolve to reflect both the latest evidence and ensure the scale of this vital technology is realised. Tidal stream energy has proven that it can be key in providing predictable, scalable renewable power, creating a thriving sector in the process. We must ensure we put in place a framework that enables responsible growth, builds trust, and delivers long-term value across communities, the environment, and those investing in a more resilient energy future. This work is part of our long-term commitment to the region, and we look forward to continuing the dialogue to support practical solutions.”
The report was developed by a consortium including Xodus Group, Carronside Consultancy, SAE Renewables, EMEC, Eurona Consultancy, Burges Salmon, Orbital Marine Power, and Nova Innovation.
