Accu, a precision engineering component distributor, has played a key role in the development of the world’s first underwater seagrass harvester, a pioneering project led by
Tandem Ventures in collaboration with marine conservation organisation
Project Seagrass. The innovation aims to tackle the urgent challenge of restoring seagrass meadows, which are vital to ocean health but have suffered a 90% decline in the UK.
Seagrass meadows, often described as the lungs of the ocean, capture carbon up to 30-times faster than rainforests, stabilise sediments and provide sanctuary for marine life. To accelerate restoration, Tandem Ventures set out to design and build a towable underwater harvester capable of trimming seagrass blades, collecting seedpods and filtering them to the surface. The challenge was to create a system robust enough for harsh marine conditions yet delicate enough to protect ocean ecosystems.
Precision engineering was critical. Accu supplied marine-grade A4 stainless steel fasteners to hold the entire machine together, ensuring corrosion resistance and structural integrity under high-pressure underwater conditions. Components ranged from M6 Torx screws for the frame to 3mm Polyfix screws securing the onboard datalogger. Tests confirmed that these fasteners maintained performance even after prolonged submersion.
Patrick Faulkner, lead engineer at Accu, explained: “The quality of the fasteners was crucial to the project’s success. We recommended our marine-grade stainless steel fasteners due to their exceptional resistance to saltwater oxidation, plus their proven strength in mechanical assemblies exposed to extreme conditions. The result was a system that performed exactly as designed; being watertight, resilient and easily maintainable by divers and engineers alike.”
Durability, accuracy and performance]Mr Faulkner added: “We are extremely proud to have played our part in this innovative project that is set to solve an important environmental challenge. Our components are designed for durability, accuracy and performance and it is very satisfying to see them being used on a project like this. This isn’t the first time we have partnered with Tandem Ventures and these innovations are truly pioneering in meeting crucial environmental needs.”
The bright yellow prototype, nicknamed ‘Thunderbird 4’, was trialled in one of the UK’s last remaining seagrass sites in North Wales. It proved highly effective, collecting seedpods in its twin-barrel filter system and demonstrating a scalable solution for future restoration. Subsequent design upgrades included reinforced extendable legs for precise cutting height, zip hatches for safe blockage clearance and a blade guard to protect marine life while maintaining cutting efficiency.
The harvester is up to 100 times faster than manual seedpod collection, a breakthrough that could transform global seagrass restoration efforts.
Edwin Towler, design engineer and wildlife presenter at Tandem Ventures, said: “We would like to thank Accu for its support in making this project possible. The result is a seagrass harvester that is up to 100-times faster than manual collection, with huge implications for restoring seagrass meadows in the seas around the UK and around the world.”
Earlier this year, Accu also collaborated with Tandem Ventures and WhaleWise on a drone-based conservation system to monitor humpback whales. For that project, Accu supplied Polyfix screws and high-performance PEEK bolts, reducing weight and improving drone flight times — further evidence of the company’s commitment to supporting innovative environmental technologies.