Lochaline Native Oyster Project Summary March 2026

Lochaline Native Oyster Project (LNOP)

Project Summary

Native oysters (Ostrea edulis) once formed an important part of Scotland’s coastal ecosystems, creating complex reef habitats, filtering water and supporting a rich diversity of marine life. Today, oyster reefs are among the most threatened marine habitats globally.

The Lochaline Native Oyster Project (LNOP) was established by CAOLAS in 2021 after early shoreline surveys revealed the near-complete loss of the loch’s historic native oyster population, with just three live oysters identified.

Since then, the project has been working towards an ambitious long-term goal: to establish a naturally reproducing, self-sustaining native oyster population in Lochaline.

Restoring oysters to Lochaline

The project purchases young hatchery-reared oysters, known as spat, and grows them within marine nursery systems before they are large enough to be released into the loch.

With support from the Nature Restoration Fund, the project has expanded considerably. Around 42,500 oyster spat were obtained during the funded phase, with a further 25,000 expected in 2026. Nursery capacity has increased, husbandry techniques have been refined, and environmental sensors now help the team respond to changes in temperature, salinity and other conditions that can affect oyster health.

Alongside growing oysters, the project is developing a much deeper understanding of the loch itself.

Hydrodynamic modelling of around 30,000 virtual oyster larvae predicted high retention within Lochaline, with 53 per cent successfully deposited on the seabed. This suggests that the shape and water movement of the loch could help retain future oyster larvae, an encouraging finding for the possibility of natural reproduction and population recovery.

There are other promising signs too. More than 35 marine species have already been recorded colonising oyster nursery structures, including mussels, scallops, anemones, sea urchins, starfish and nudibranchs. Surveys have also found remnant adult native oysters, while analysis of oysters from an earlier release found evidence that some are reaching reproductive maturity.

Learning as restoration develops

Restoration is also about learning what works. Detailed monitoring identified sedimentation as an important challenge at the original release site, leading the project to investigate and select more suitable areas for future releases. Monitoring now covers 19 ecological measures, from temperature and salinity to seabed composition, sedimentation and oyster reproductive condition.

Importantly, this work has been designed to remain practical for continued community-led monitoring.

Local participation is central to LNOP. Volunteers have been trained in nursery maintenance, environmental monitoring and biodiversity surveys, while education activities have engaged 128 primary school pupils across six schools, alongside secondary and university students.

Looking towards a living oyster reef

The next stage will build on what has been learned so far. Priorities include further oyster releases, trials to improve suitable settlement habitat, continued environmental monitoring, and exploration of ways to create the three-dimensional structure needed for a developing oyster reef.

The ultimate ambition remains the same: a thriving native oyster population that can reproduce naturally, support biodiversity and once again form part of the living ecosystem of Lochaline.

Explore the full report

The full Lochaline Native Oyster Project Summary explores the project’s restoration methods, nursery performance, ecological monitoring, larval modelling, biodiversity findings, community participation and plans for the future.

Download the full report to discover how native oyster restoration is developing in Lochaline.