Dún Laoghaire Harbour’s East Marina Breakwater is now the location for a new oyster trail walk initiated by Green Ocean, the volunteer-led Irish marine charity.
The Green Ocean Oyster Trail Walk comprises a series of four signs, each linked by QR code to a short video, which relate the story of the native oyster’s decline in Dublin Bay and along Ireland’s east coast.
It also explains how Green Ocean is bringing this “eco-engineer” back to our waters.
The East Marina Breakwater is a short pier within the main harbour, directly in front of Dún Laoghaire Marina.
The walk takes about 16 minutes from start to finish and takes in the busy vista of boats and sailing activity in and around the harbour.
Green Ocean describes it as “a place of real tranquillity, somewhere to pause and take in the moment”.
The trail is designed for all ages, young and old. As visitors follow the signs and watch the videos, they are invited to ask themselves a simple question: what can I do?
Green Ocean’s aim is that everyone who walks the trail comes away knowing they can be part of the solution, for people and nature alike.
Shell Company: Green Ocean's Aoibheann Boyle, Róisín Finlay and David Lawlor with Green Kite funders Anke Heydenreich and Mary Lovegrove, and Green Ocean's Tierney Kist, at the Dún Laoghaire Oyster Trail launch Photo: Michael Chester
In 2023, Green Ocean asked a simple question: would native oysters survive in Dublin Bay?
A series of pilot phases in Dún Laoghaire and across the bay, guided by scientific partners at the DCU Water Institute, gave a clear answer. The waters of Dublin Bay are ready for the return of the native oyster.
The native oyster, also known as the European flat oyster, is an ecological keystone species. Oysters play a highly effective role in nutrient cycling, helping to stabilise the sea floor and improving water quality and clarity.
Clearer water encourages seagrass and seaweed to spread, creating habitats that are vital spawning grounds for marine life and support a wider ecosystem of predators.
In 2025, Green Ocean built on the success of its Dún Laoghaire pilot by installing 18,000 oysters in 300 floating baskets within Dún Laoghaire Harbour. These oysters form a broodstock population, designed to encourage oysters to self-seed naturally in the harbour and across Dublin Bay.
The Oyster Trail Walk explains the techniques behind this work, so visitors can see the restoration happening right in front of them.
The work has continued to grow throughout 2026. Green Ocean has been trialling a range of oyster spawning techniques to help build resilient oyster populations in Dún Laoghaire.
The science has expanded too, with the installation of a water sensor in the harbour and a growing research programme with the DCU Water Institute.
Over the past three years, Green Ocean has mobilised the local community, and today more than 50 active volunteers contribute almost 3,000 hours a year, playing their part in improving the health of our marine ecosystems. Their time, energy and enthusiasm have turned a simple question into a thriving, community-powered restoration project.
David Lawlor, founder and team lead of Green Ocean, said: “When community, scientists, businesses and councils come together in a spirit of hope, amazing things can happen, and Dún Laoghaire is proof of that. Recovery is possible, not because nature was left alone, but because people chose to help. You don’t need to be a scientist to be part of it. You just need to care.”
Professor Fiona Regan, director of the DCU Water Institute, said: “Dún Laoghaire Harbour has become a true living lab. Data from the water sensor, together with research on oyster growth and spawning, is helping us understand how native oysters can recover in Dublin Bay. Just as importantly, the Oyster Trail brings that science out of the lab and onto the pier, showing how research and community action can work hand in hand.”
Tim Ryan, operations manager, Dún Laoghaire Harbour, said: “Dún Laoghaire Harbour is proud to be home to Green Ocean’s oysters and now to the Oyster Trail Walk. The East Marina Breakwater is a beautiful spot, and the trail gives everyone who visits a new reason to stop, look and learn about the life in the water around them. We hope that this will be the first of many experiences on a future biodiversity tour within Dun Laoghaire Harbour.”
Anne Murray, biodiversity officer, Dún Laoghaire-Rathdown County Council, said: “Restoring native oysters is about far more than one species. It supports cleaner water, richer habitats and a healthier Dublin Bay. Projects like this, led by local volunteers and grounded in science, show how communities can play a real part in protecting biodiversity on our own doorstep.”
As Afloat previously reported, east coast yacht clubs have supported the restoration project, which has also expanded to Greystones Marina. David Lawlor discussed the origins of the initiative in Afloat’s Wavelength podcast.
