Tandem Ventures has worked with a group of engineering partners to help conservation charity Project Seagrass to design, develop, build and test a new automated underwater harvester that will cut and collect seagrass seed pods.
Seagrass meadows, often called the lungs of the ocean, are vital for sustaining marine life, capturing carbon at impressive rates, and stabilising coastal environments. Yet, with the UK having lost over 90% of its seagrass, there is an urgent push to restore these crucial underwater habitats. At the centre of this effort is a collaboration between Tandem Ventures, precision engineering distributor Accu, and conservation charity Project Seagrass, resulting in the world’s first automated underwater seagrass harvester.
Traditionally, harvesting seagrass seed pods involved divers manually collecting each pod, a slow and labour-intensive process that limited restoration scale and speed. Recognising the need for innovation, Tandem Ventures gathered engineering partners to automate the process with sensitivity to the marine ecosystem.
The outcome is a towable, bright yellow harvester prototype, nicknamed ‘Thunderbird 4’. Designed with Project Seagrass and engineered using PTC’s Onshape, the craft was developed through real-time collaboration across locations, allowing rapid design iteration in response to daily test findings in the challenging conditions of Porthdinllaen Bay, Wales—one of Britain’s last thriving seagrass meadows.
The harvester is about the size of a small car, featuring custom 3D-printed components from Bambu Lab in tough TPU and PLA materials. Its sophisticated datalogging ‘brain’, supplied by Mouser Electronics, records crucial environmental data—depth, orientation, pressure, turbidity, and temperature—to inform researchers and guide improvements.
Marine-grade A4 stainless steel fasteners from Accu Components hold everything together, from robust M6 Torx screws for the frame to delicate 3mm Polyfix screws for the datalogger. Their corrosion resistance and strength were essential for ensuring the harvester’s durability and ease of maintenance for divers and engineers.
Initial tests showed the harvester’s new pump-filter system could efficiently collect seed pods with minimal environmental impact. The prototype proved up to 100 times faster than manual methods, marking a transformative leap in restoration potential. Encouraged by these results, the team added upgrades like reinforced extendable legs for adjustable cutting height, zip hatches for safe blockage clearance, and a blade guard to protect marine wildlife while maintaining performance.
Tandem Ventures continues to refine the design, including a new pumping system inspired by sci-fi technology, to enhance reliability and simplicity. Innovations from this project are already influencing global restoration, with the team hopeful for widespread environmental benefits.
Beyond seagrass, Accu and Tandem Ventures have also collaborated on other conservation technologies, such as lightweight, corrosion-resistant fasteners for drone-based whale monitoring with WhaleWise. These partnerships showcase how precision engineering and inventive design can help address significant ecological challenges.