Restore the Native Oysters in Loch Craignish

Photo: Danny Renton

Seawilding – Loch Craignish Native Oyster Restoration Project

Project aims

The project, run by the Scottish charity Seawilding and funded by the National Lottery, aims to restore the native oysters that were once prevalent in Loch Craignish. Working with the community, the project aims to grow up to 1 million native oysters in a floating nursery at Loch Craignish, and to translocate the oysters to suitable pre-surveyed sea-bed sites around the loch. The project released its first 60,000 native oysters in October 2020, and a further 70,000 will over-winter in the nursery for release in 2021. The long-term aim is to enable a sustainable community-owned native oyster fishery.

Key stakeholders

The project has partnered with local volunteer association CROMACH (Craignish Restoration of Marine and Coastal Habitats); the Ardfern Yacht Centre, Heart of Argyll Wildlife Organisation as well as the Institute of Aquaculture, Stirling University, and the Scottish Association of Marine Sciences.

Grading oysters at the Loch Craignish nursery. (Photo: Danny Renton)
(Photo: Eric Holden, Narwhal Expeditions)
Left: Measuring oysters; Right: Newly restored oysters at low spring tide. (Photos: Danny Renton)

Restoration Approaches

All juvenile native oysters are being sourced from Morecambe Bay Hatchery. However, soon, we hope to conduct research into the genetics of the small relic native oyster population scattered around Loch Craignish, as well as those being introduced, in order to create brood stock of appropriate genetic variability. 

Our floating nursery on a 160-metre longline enables us to grow oysters from 8-12mm up to a good size (between 8-15 grammes) for release on the seabed. We have not introduced additional culch as there is an abundance of cockle, oyster and horse mussel shell on the seabed. Once restored to the seabed, the oysters will be closely monitored.

Our partnership with academic institutions will yield multiple research opportunities and during the project lifetime, we expect 20 MSc students to be involved. Additionally, we have suspended sponsored “Oyster Hoisters” beneath the Ardfern Yacht Centre pontoons to enable citizen science with five local primary schools, yacht owners and the local community.


Danny Renton
Project coordinator