Â鶹´«Ã½

The innovative new technique is currently being trialled by local companies HydroSurv in Exeter and Totnes based Valeport, working with the Â鶹´«Ã½ and Natural England, and supported by a grant of more than £266,000 from Innovate UK’s Smart Grants programme.

It builds on the concept of the acoustic reflectivity of seagrass providing valuable information to characterise submerged aquatic vegetation. Valeport’s VA500 altimeter, a hydrographic instrument used for measuring underwater positioning, is installed onto a small Uncrewed Surface Vessel (USV), built by HydroSurv and with specific modifications for this project. Remotely controlled and with no people onboard, the USV provides a non-invasive and cost-effective platform for seagrass site survey.

A large, validated signal library and deep learning algorithm, developed by the Â鶹´«Ã½, deciphers the survey data collected by the USV to predict seagrass distribution. The data is visualised and interpreted within a cloud application created by HydroSurv.

Seagrass meadows are a crucial part of the marine ecosystem and are increasingly being recognised for their essential carbon capture abilities. As well as being as effective at storing carbon as woodland, seagrass also provides vital habitat for young fish, seahorses and jellyfish. It additionally cleans surrounding seawater and helps to stabilise the seabed, thereby reducing coastal erosion.

The USV platform facilitates accurate repeat surveys that can be compared to monitor temporal changes in seagrass coverage for the planning of protection and regeneration projects at biodiversity-rich worksites.

The full solution, which was demonstrated successfully to project stakeholders in Cawsand Bay, Looe and on the River Yealm for the first time in May this year, is set to change the way seagrass meadows are monitored in the future, complementing traditional diver surveys to cover much larger areas and enable rapid re-survey work as required.