What lies beneath
On a recent visit to Mull, I spent a wet and windy hour in the tiny museum in Tobermory. Staffed by volunteers with copperplate handwriting, the Mull Museum is crammed with artefacts and stories about Tobermory and its relationship with the sea.
One display chronicles the many attempts over the last five hundred years to salvage the wreck of the San Juan de Sicilia, a ship from the Spanish Armada now buried under five metres of silt at the bottom of Tobermory Harbour with a rumoured £30 million of treasure still on board. Countless expeditions, the most recent in 2014, have retrieved ships cannon, a handfuls of coins and a few pieces of pottery. But less than 40 nautical miles south at Loch Craignish there is a group more interested in burying treasure than unearthing it.
Hundreds of small hessian bags, possibly similar to those used to hold Spanish treasure, are being dropped onto the floor of the sea Loch by scientists and volunteers from Scottish charity Seawilding. Each bag contains a tiny spoonful of seagrass seed, mixed with a handful of sand to weight it to the silty Loch bed until the seed can germinate and form its own roots. The seed is harvested from the 0.5 hectares of seagrass meadow that remain at Loch Craignish, extracted, sifted, and replanted in carefully chosen sites. Seawilding estimates show that the remaining meadows, although tiny are host to 68% of the total biodiversity across this vast loch.
Note: All the above images are from the Ocean Image Bank and are of seagrass meadows in Cornwall
Seagrass (zostera marina), also known as eel grass, is a strap leaved, deep rooted plant that grows in shallow seawater and used to be a common site along the UK coasts. As the only flowering marine plant seagrass captures carbon from the atmosphere by photosynthesis, and stores it in the root system. The broad, waving fronds filter seawater as it flows over them and provide shelter and sustenance to a wide variety of marine life from micro-organisms to tiny fish, oysters, crabs, and prawns.
Seawilding was established to address the dramatic biodiversity loss in the Scottish marine environment which has swiftly accelerated since the lifting of the 3 mile inshore fishing limit in 1984. The limit which served to protect these shallow water eco-systems for more than a century, was revoked in response to pressure from the Scottish fishing industry complaining about the disappearing fish stocks in the deep water fishing grounds. Since then, boats dragging broad, weighted nets have been allowed to dredge the inshore regions for shellfish tearing up the seagrass meadows and everything that lives in them and leaving behind lifeless, shifting silt. By contrast creel fishing, using traps designed to catch a single species offer a much more sustainable, but more labour intensive alternative.
In The Custodians, a recent documentary from Patagonia films, Seawilding founder Danny Renton explains his charity’s plan for a seagrass planting program that doesn’t require expensive equipment or technology. His aim is to share this with other community groups in Scotland and beyond, particularly in areas where biodiversity funding may not be available.
It is slow, painstaking work and heavily reliant on an army of volunteers, to harvest and process seed, fill bags, and snorkel out to the planting sites armed with their tiny sacks of treasure. At the current rate the charity is able to replant only 0.25 hectare each season. But given the biodiversity gain that this represents the rewards from even such a small area are massive and long-lasting.
Seawilding’s scientists estimate that over 90 hectares of the Loch Craignish floor is suitable for seagrass meadow, and marine scientist Ailsa Mclellan explains that Scotland’s long coastline and relatively small landmass mean that the seabed, represents a greater opportunity for carbon capture than all the peat, forestry, and grassland in the country. The weekend I visited Mull coincided with the Great Seagrass Survey, a citizen science initiative jointly organised by Seawilding and Project Seagrass, a Welsh based seagrass conservation charity. The Survey invited snorkelers, divers, wild swimmers and paddle-boarders from across the UK to identify and map their local seagrass beds and share their data to build a national picture of the state of our seagrass meadows.
Alongside seagrass restoration, Seawilding and their army of volunteers have already re-introduced more than 300,000 native oysters back into Loch Craignish having nurtured them in specially designed nursery cages until they are large enough to survive in the loch. Their ambition is to have rewilded a total of 1,000,000 of these by 2025. This is their contribution to the rebuilding of a sustainable fishing industry in the West of Scotland. Danny Renton explains, ‘We’re creating a different management system for a sea Loch that puts biodiversity and health of the water at the forefront of everything.’
It seems to me that whatever the value of the Spanish treasure, buried at the bottom of Tobermory Harbour, Seawilding and organisations like them have revealed greater wealth much closer to the surface. Although Orcas, Dolphins and other photogenic species attract more media attention during campaigns like World Ocean Day their continued existence depends on the health of the seabed at the grassroots level.
