Automated Seagrass Planter aims to restore and preserve vital coastal ecosystems

Environmental engineering company, Land & Water Group, has led the development of a new system for automating seagrass planting.

Land & Water

Earth Change, a division of the Land & Water group, an environmental engineering company, has collaborated with marine conservation organisation Project Seagrass, to develop and test an Automated Seagrass Planter (ASP). 

The patent pending ASP aims to revolutionise the large-scale planting of seagrass to rejuvenate degraded habitats, enhance coastal resilience, and promote marine biodiversity. A trial was conducted in Dale Bay, Pembrokeshire, during June 2023, to test the scalable prototype. The project aims to restore and conserve the UK’s seagrass ecosystems, as well as to raise awareness of its importance and work towards its future protection as it mitigates climate change by capturing carbon dioxide from the atmosphere.

In Britain, most of the planting of seagrass is done by hand at low tide, or by divers at a high cost and low output. The ASP aims to reduce the time and effort needed for manual planting, as well as to minimise the environmental impact and invasiveness of divers standing on the seabed and creating holes by hand.

Instead, the ASP is placed on the deck of a multicat vessel and then lowered onto the seabed. The bags of seagrass are then automatically planted, and the ASP is lifted back onto the deck with little disruption or waste, and the action then repeated.

The automated process will enable over 2,000 biodegradable seapods/hessian sacks of seagrass to be planted a day, guided by GPS to exact pre-assessed locations and to exact depths in tidal waters of up to six metres deep. Each location ensures optimal growth conditions and maximum survival rates for the new seagrass habitats. The entire process is estimated to be at least four times as fast as manual planting, creating a natural solution to the climate crisis, as large-scale restoration projects are said to be more efficient and achievable than ever before.

James Maclean, CEO of Land & Water, said: “We are now convinced we can substantially scale up seagrass glade restoration using the automated planter, taking conventional planting to sea-scape scale planting at 1000’s of plants per day”. Project Seagrass, alongside Swansea University, will monitor the trial on an ongoing basis to validate the effectiveness of the new planting regime.

Globally, seagrass has the capability to capture carbon faster than tropical rainforests, accounting for 10 to 18 per cent of the ocean’s carbon storage, despite covering less than 0.1 per cent of the seafloor. However, due to human activity and natural disturbances, seagrass habitats have been rapidly declining worldwide. It has been found that at least 44 per cent of the UK’s seagrass has been lost since 1936 – most of it likely since the 1980s. According to PhD Candidate Alix Green and Dr Peter Jones of the UCL Geography department, when mapping which coastal areas were once likely to have been suitable for seagrass growth, as much as 92 per cent of the UK’s seagrass might have disappeared.