Sea Synergy Oyster Project

Why Ostrea edulis?
O.edulis is a bivalve, meaning it is a mollusc that has two shells. It is a filter feeder, meaning they pump water across their gills filtering out microscopic algae and small organic particles from the surrounding water. This feeding method means a single oyster can filter up to 200 litres of seawater per day. The larvae of O.edulis like to settle in close proximity to adult oysters often on top of them, this results in the formation of complex 3D structures referred to as oyster reefs.
O.edulis was once very common in European coastal waters but due to overfishing, disease and the introduction of invasive species its population has declined by 95% in UK and Irish waters. This decline means O.edulis reefs are categorised as ‘Critically Endangered’ on the European Habitat Red List.
O.edulis reefs provide many ecosystem services – improved water clarity and quality, making photosynthesis easier for other organisms and improving the health and biodiversity of the surrounding environment. Reef structures stabilises the sea bed, reduces coastal erosion, provides shelter, living space and food for many marine organisms.

Why the Portmagee Channel?
The Portmagee Channel in south-west Kerry is home to a relic population of O.edulis, that is understudied and has some of the largest living specimens ever discovered. In 2009 a living O.edulis was found on the shores of the channel measuring 178mm in height, the largest oyster ever recorded in UK and Irish waters.
The Portmagee Channel is also a Special Area of Conservation, SAC and home to additional rare, and endemic species. Such as Edwardsia delapiae or Maude Delaps Anemone, discovered in the 1920’s and is not found anywhere else in the world. The Horseshoe Worm Phoronis psammophila which has not been recorded elsewhere in Ireland or Britain. The Channel also has other significant marine habitats such as Eelgrass and Maërl beds.

Our aim this year;

1. Map the distribution and population density of the Native European Oyster (Ostrea edulis) within the Portmagee Channel
2. Survey the biodiversity associated with O.edulis within the Channel
3. Involve the local community in citizen science recording events and develop and erect two information boards

Our Funders and Supporters;
Our work this year has only been made possible because of the funding we have received.

1. NPWS National Parks and Wildlife Services grant for small recording projects 2023. Purchase the equipment, field guides and training necessary to conduct surveys within the channel and record and process the data from these surveys.
2. Galway Atlantaquaria Grants for Small Conservation Projects 2023. The support of an intern who is a current student of marine biology or associated degree to receive training and invaluable experience in the field.

Looking to the Future;
Continue with baseline surveys of the O.edulis population, the associated biodiversity and the abiotic factors pertinent to oyster survival within the channel. This data will then be used to produce a feasibility report for the restoration of a native oyster reef within the channel and assist us in securing further funding and support.
With the hope of increasing the size of the oyster population, the extent of the oyster habitat and the biodiversity within the Portmagee Channel. As well as improving the local understanding and appreciation of the species and the habitat it creates, and a growth of ecotourism in the area.

How to get involved

Join one of our Citizen science days, meet the research team, participate in a survey and improve your shoreline ID skills.

• Saturday 30th September – 11:00-13:00
• Wednesday 4th October – 14:00-16:00
• Thursday 12th October – 09:30-11:30
• Saturday 14th October – 10:00-12:00

Contact us for further details or to join an event.