The Great Barrier Reef is home to seagrass meadows, which are vital for the health of the reef. These meadows store carbon, shelter marine life, and feed sea turtles and dugongs. However, climate change, extreme weather, declining water quality, and coastal development have led to severe losses in these critical ecosystems. A new technology, an underwater robot, is offering fresh hope for their recovery. The robot, custom-built to plant seagrass seeds and restore meadows, has been trialled for the first time on the Great Barrier Reef. Led by the Great Barrier Reef Foundation, in partnership with marine robotics company Ulysses and Central Queensland University (CQU), the trial tested a new approach to one of the reef's biggest restoration challenges: how to bring seagrass meadows back faster and across much larger areas. Seagrass meadows cover an estimated 35,000 square kilometers of the Great Barrier Reef. These underwater forests play a powerful role in keeping the reef healthy, absorbing and storing vast amounts of carbon, improving water quality, stabilizing sediments, and providing food, resting, and breeding grounds for marine life. However, traditional restoration methods, such as hand-collecting and spreading seeds, are slow, labor-intensive, and costly. CQU's Emma Jackson, Director of the Coastal Marine Ecosystem Research Centre, highlights the logistical issues with getting seeds out onto large intertidal meadows, which are a real impediment to seagrass restoration at scale. To meet the scale and urgency of the challenge, new tools are needed, and that's where robotics comes in. The robot, named Mako, can map the seafloor and plant seeds with precision, using small robotic drills to place seeds directly into the sediment. The trial delivered several positive results that showed this technology should be explored further: robotic drills could place seeds at the correct depth, quickly and accurately; operation was reliable in fast-moving, murky, high-energy waters; and the modular design allowed parts to be easily repaired or replaced. However, the project also revealed areas for improvement, such as maintaining consistent seed flow as supplies ran low and ensuring seeds were planted at the ideal depth when sediment conditions changed. Despite these challenges, the team is optimistic about the future of seagrass restoration. The ultimate goal is an underwater vehicle that not only plants seagrass but also collects seeds and monitors restoration sites, further reducing the time and cost required and making large-scale seagrass restoration financially viable. After the success of this trial, the team plans to continue scaling seagrass restoration in Gladstone and the Great Barrier Reef, planting larger and larger sites and restoring more and more seagrass to bring life back to this ecosystem.
