Seagrass Restoration
Since 2021, Seawilding has pioneered Scotland’s first community-led seagrass marine restoration project. We trial multiple methodologies to understand how best to restore seagrass, at the lowest possible cost and at scale.
Loch Craignish has ten small seagrass meadows totalling approximately 5 hectares, and while these seem dense and healthy, they are isolated and fragmented. Yet, our extensive surveys in the Loch suggest there’s around 80 hectares of seabed ripe for restoration.
Seagrass, Zostera marina, also known as common eelgrass, is an essential keystone species which sequesters carbon while providing a vital habitat and spawning ground for fish and other marine species. At Loch Craignish, there are twice as many marine species in seagrass, compared to non-seagrass sites and despite seagrass meadows making up 0.4% of the area of the Loch, they host an incredible 68% of the biodiversity. Yet, globally, 92% of seagrass has now gone and in the fight against climate change and biodiversity-loss, restoring seagrass is a top-priority.
A seagrass
meadow
At Loch Craignish, we have been trialling multiple methodologies, but owing to muddy seabed sediments lacking in oxygen, failure rates are high. In 2024, we planted 8,000 rhizomes (seagrass with roots intact) into a well-oxygenated area of seabed at Dunvhullaig bay in Loch Craignish, and after six months we’d seen a 5-fold increase in coverage. Hopefully, we’ve cracked it. In 2025, we plan to plant approximately 1/3 hectare.
How to restore at scale?
In 2023, in a UK first, we planted ¼ of an acre of seagrass rhizomes by translocating plants from the donor meadows to the restoration areas. This methodology has been successful in Canada and if successful in Scotland, we believe rhizomes may be the answer to restoration at scale.
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Images: above, volunteers processing rhizomes, getting them ready for transplanting into our restoration area. Top, our team planting rhizomes out into our restoration area.
Seagrass, Zostera marina, also known as common eelgrass, is an essential keystone species which sequesters carbon while providing a vital habitat and spawning ground for fish and other marine species. Our surveys in Loch Craignish reveal that there are twice as many marine species in seagrass, compared to non-seagrass sites and despite seagrass meadows making up 0.4% of the area of the Loch, they host an incredible 68% of the biodiversity. Yet these biodiversity hot-spots have disappeared around the UK owing to dredging, pollution and disease, and globally 92% of seagrass has now gone. In the fight against climate change, restoring seagrass is a top-priority.
Over fifty species of fish have been recorded in one meadow along with hundreds of species of invertebrates such as molluscs, shrimp and marine worms. By providing a 3-dimensional structure in an otherwise barren marine landscape, seagrass provides a vital marine habitat.
Images: Will Goudy, Alasdair O'Dell, Philip Price
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"It's inspiring to be able to be involved in such an important project." Seawilding Volunteer 2024, Loch Craignish