For the last few months, experts at the Ocean Conservation Trust (the OCT) have been testing a suite of new marine technologies – including a specialised Remote Operated Vehicle and an underwater seed blaster – that could “revolutionise” the approach to UK seagrass conservation.

Restoring seagrass both quickly and efficiently has been pinpointed as “imperative to tackling the current biodiversity crisis” as well as playing a pivotal role in climate change. Seagrass is recognised as one of the most valuable and biodiverse habitats on the planet and one of the few that provide multiple benefits to the environment.

Yet, it’s facing some major challenges. Human-driven impact such as pollution and disease has led to the dramatic decline in seagrass meadow in UK waters with area coverage diminishing by as much as 90% over the course of the last century.

To help in its efforts to achieve large-scale restoration of UK seagrass levels, the Ocean Conservation Trust has been trialling new methods for both planting seagrass in the marine environment and mapping and monitoring the areas in which it is growing healthily.

Partnering with the Plymouth-based engineering company, Absolute Product Design, the OCT has developed a new, purpose-built seed-firing mechanism which – borrowing heavily from the on-land planting process known as hydroseeding – has proven to plant up to 2,000 seagrass seeds in the marine environment in just 20 minutes.

Based on the caulking gun design, the spring-loaded handheld device (named the Ocean Conservation Trust o Pressurised Underwater Seeder, or OCToPUS for short) is fitted with a 1.5 litre chamber for storing the seeds of the Zostera marina seagrass. Using the newly developed technique of Hydro Marine Seeding, the OCT’s Ocean Habitat Restoration team has successfully completed the restoration of 1.5 hectares of seagrass meadow in the Solent Maritime Special Area of Conservation and 2 further hectares in Plymouth Sound National Marine Park.

Already, preliminary results are indicating the positive and vital regeneration of seagrass beds across each area.

“We focus entirely on subtidal seagrass, and with that there are a variety of additional challenges that come with working below the waves,” said Amelia Newman, seagrass aquaculture technician lead at the OCT. “So, we are really excited to be at this stage with our new device and starting to see how it could revolutionise the OCT goes about restoring this vitally important habitat.”

Seagrass meadows are highly efficient carbon sinks which not only improve water quality but provide food and shelter to a number of important species including the sandeel and herring. They also absorb carbon up to 35 times more efficiently than tropical rainforests and, despite only covering 0.2% of the seabed, store around 10% of the carbon found within the ocean.

But they are also facing an annual decline. It’s according to the International Union for the Conservation of Nature (IUCN) that as of 2014, seagrasses were declining by 7% each year globally. This makes it the fastest disappearing habitat on the planet. The IUCN also suggests that since the 1930s, up to 90% of Zostera marina seagrass beds have been lost, largely through physical disturbance, pollution, and disease.

“But, groups like the Ocean Conservation Trust have shown that we can bring it back,” said Samir Whitaker, biodiversity lead specialist at Ørsted, who partnered with the OCT on the project. “Restoring seagrass efficiently and quickly is imperative to tackling the biodiversity-climate crisis and we are delighted to have supported the development of the OCToPUS.

“We firmly believe that a combination of collaboration and innovation will be key to achieving real progress in biodiversity protection, preservation, and restoration.”

But restoration within the marine environment isn’t the only challenge the OCT faces, mapping and monitoring these sensitive habitats is also quite the endeavour. But with thanks to the development of a custom-built Remote Operated Vehicle (ROV) – built in partnership with Sonardyne, MarineSee, Voyis, and Blue Robotics – it’s a job that’s about to become a whole lot easier.

Using state-of-the-art underwater positioning technology, the new ROV is capable of producing high-resolution photogrammetry to enable seagrass mapping and monitoring “in unprecedented detail.” It’s also hoped that, thanks to its improved ease of operating, this new technology will enable the OCT to better understand seasonal and annual change in seagrass meadows as the team performs routine monitoring exercises throughout the year.  

“We are dedicated to protecting and restoring seagrass meadows in the Southwest and beyond, so it’s thrilling to see how we can build upon our efforts with these exciting devices and technologies,” said Mark Parry, head of ocean habitat restoration at the OCT.

“It’s great to be working with a team of passionate people at the OCT who think outside of the box, as well as receiving support from our partners and local organisations to help us conserve these vitally important habitats.”

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