THE largest seagrass restoration project ever undertaken in the UK has been launched in an ambitious £1.8 million marine recovery programme in Cornwall.

Mor Nature - Cornwall’s first seascape-scale marine restoration initiative, named after the Cornish word for sea, mor – is a new partnership between the Ocean Conservation Trust (OCT) and Cornwall Wildlife Trust (CWT) and aims to contribute towards 2043 government targets to increase seagrass by 15 per cent compared to 2024 levels.

As well as plans to restore 10 hectares of seagrass meadow in Falmouth Bay, the project includes the restoration of native oyster populations across the Fal and Helford Special Areas of Conservation through a combination of active habitat restoration, monitoring and community stewardship.

Seagrass meadows are among the most important habitats in the ocean, supporting biodiversity, improving water quality, storing carbon and protecting coastlines from erosion, while delivering significant cultural and wellbeing benefits for local communities. Healthy seagrass habitats are needed to provide an essential ecosystem that underpins the resilience of coastal communities and economies.

A single hectare of seagrass can support 80,000 fish and 100 million small invertebrates. The underwater meadows are also a home for rare and endangered species, like seahorses and stalked jellyfish. Seagrass is one of the world's most effective natural carbon sinks, absorbing carbon up to 35 times more efficiently than tropical rainforests, and storing 10 per cent of the ocean’s carbon.

The restoration site stretches between Swanpool and Pendennis Castle in Falmouth Bay, where OCT first established protective measures in 2022 through the installation of Sensitive Habitat Marker Buoys and voluntary no-anchor zones.

The project also builds on CWT’s extensive work in the area to map and monitor the existing seagrass meadows, and will expand its network of intertidal seagrass restoration sites. CWT will also work with fishers, community groups and citizen scientists to establish new oyster nurseries in the Helford.

Over the past winter, OCT's team cultivated more than 21,000 seagrass seedlings at its National Seagrass Nursery in South Devon. These plants will be transplanted into the restoration site, alongside thousands of additional seeds deployed using innovative restoration technology developed by the charity. The work is highly complex, requiring months of cultivation, specialist logistics, vessel operations and underwater installation by trained divers, all while navigating changing tides, weather conditions and challenging underwater visibility.

OCT conservation project manager Andy Cameron said: “Mor Nature represents a major milestone for marine restoration in the UK. We're not simply planting seagrass; Mor Nature represents the holistic cultivation of an entire underwater garden, nurturing the relationships between interdependent species and habitats that will allow a plethora of marine life to thrive.”

By working collaboratively, partners aim to create conditions that support a wide range of marine species, including seahorses, spider crabs, cuttlefish, bass and sharks.

CWT head of marine conservation Dr Dan Barrios-O'Neill said: “Native oysters were once a defining feature of Cornwall's seas, creating thriving underwater habitats that supported wildlife, fisheries and coastal communities. Through Mor Nature, we have an opportunity to restore not only oyster populations, but the ecological functions they provide.”