Fish Guidance Systems has presented a detailed argument advocating the use of Remotely Operated Vehicles (ROVs) to address safety concerns in the maintenance of Acoustic Fish Deterrent (AFD) systems at Hinkley Point C. 

It has previously presented this at Environment Agency, Welsh Government and UK Government Public Inquiries, the latter two finding in FGS’s favour. Its approach not only aligns with technological advancements and environmental protection standards, but also ensures the safety and efficiency of maintenance operations.


The Environment Agency’s requirement for an AFD system at Hinkley Point C has been supported from both a technological, best practice and environmental basis. 

The impact of an AFD-less system on marine life, particularly in the sensitive ecosystem of the Bristol Channel has been totalled at billions of fish. Despite EDF’s appeal against this requirement citing safety and cost concerns, the Planning Inspectorate upheld the need for AFD, emphasising its importance for marine conservation and the lack of research and development from EDF on finding genuine solutions. The main concern is safety of divers for maintenance. FGS has spoken to ROV manufacturers and states its position below.

Safety and Feasibility of ROV Maintenance:

An independent ROV manufacturer has conclusively reviewed the AFD project at Hinkley Point C, affirming that the maintenance of the AFD system using ROVs is “very doable” with currently available technology. This directly challenges EDF’s concerns, proving that ROVs can safely and effectively maintain AFD systems.

Advantages of ROVs:

  1. Safety: ROVs significantly reduce the risk to human divers by performing maintenance tasks in challenging underwater conditions, including high turbidity and strong tidal flows characteristic of Hinkley Point C.

  2. Efficiency: ROVs are capable of operating in the demanding environmental conditions of the Bristol Channel, where strong tidal flows and variable water depths necessitate adaptable and resilient maintenance solutions.

  3. Environmental Protection: The use of ROVs ensures the AFD system functions optimally, providing the best possible protection for marine species by minimising the risk of fish mortality through impingement.

EDF’s Consideration of AFD Installation:

Despite initial reservations, it is evident that with the advent of sophisticated ROV technology EDF can address its safety concerns. The commitment to installing an AFD, as per the Environment Agency’s best practice guidance, is both feasible and necessary to meet environmental protection aspirations for the next 60 years.

Call for Site-Specific Optioneering:

Given the distinct environmental conditions at Hinkley Point C compared to other locations like Sizewell C, FGS urges EDF and the Planning Inspectorate to conduct a site-specific optioneering phase. This will ensure the development of the most suitable AFD deployment system, taking into account Hinkley Point C’s unique challenges, including its deeper water depths and higher tidal flows.


The evidence and expert opinions gathered clearly indicate that the maintenance of AFD systems at Hinkley Point C using ROVs is not only possible but advisable. This approach mitigates safety concerns, enhances operational efficiency, and most importantly, upholds the environmental protection mandate for marine life in the Bristol Channel. FGS strongly recommends that EDF revisit its decision against AFD installation, considering the robust capabilities of ROVs and the critical environmental benefits of the AFD system.

Fish Guidance Systems Ltd remains committed to innovative solutions for marine environmental protection, advocating for responsible and sustainable practices in industrial operations impacting marine ecosystems.