The Green Ocean Foundation has upgraded its oyster‑restoration project in Dublin Bay with the recent installation of a new string of marine baskets along the northern fairway at the eastern breakwater of Dun Laoghaire Marina.
More than 18,000 oysters are being deployed in Dún Laoghaire harbour in Dublin in the next phase of an initiative to reintroduce the shellfish to Dublin Bay over 200 years after they became extinct from the area.
It is hoped the oysters, which will not be for commercial use, will bring environmental benefits to the waters they are in.
The native adult Irish oysters, which were harvested from the waters off Co Kerry, will be placed into the harbour in specialised floating flip baskets by 20 volunteers.
It's part of ongoing efforts to create an oyster reef along the Dún Laoghaire breakwater.
Fifty “Oyster Gardens” were installed across marinas in Dun Laoghaire, Malahide and the River Liffey at Poolbeg in November 2023.
Each garden was a marine basket with 10–15 adult oysters, suspended one metre underwater from pontoon walkways.
The goal was to establish a self‑sustaining brood stock in Dublin Bay that will turn into reefs over 15–20 years.
These reefs are expected to support seagrass and seaweed beds, and help protect the coast from erosion.
In the project’s first year, oyster mortality was kept below 3 %. Spat settlement was observed in summer 2024. Students from University College Dublin and Trinity College Dublin were studying the health and reproductive success of the oysters.
Expansion in October 2024 included new and existing locations in Dublin Bay as well as the support of six yacht clubs.
“Our focus remains on biodiversity enhancement, carbon‑sequestration and community engagement,” a Green Ocean spokesperson said.
The upgrade in Dun Laoghaire Marina scheduled for November 2025 will increase capacity and reach.
Listen to David Lawlor of the Green Ocean Foundation in Afloat's podcast from January 2024 here
