The seagrass meadows have been known for long time to play a vital ecological role worldwide as nurseries for many marine creatures, including commercial fish, and to protect the shoreline from erosion acting both as a trap for sediment and a buffer system for the waves. Much more recent is the acknowledgement of the climate value of the seagrass beds, which have been estimated to be responsible for 15% of carbon stored in the ocean.
However, the knowledge about the distribution of these fundamental marine ecosystems along the Irish coastline is still fragmented. Mainly two species of seagrass can be found in Ireland, i. e. Zostera marina, which spans from the intertidal to the subtidal environment, and Z. noltii, which is strictly an intertidal species instead. Many are the threats to the survival of the seagrass meadows, ranging from the overgrowth by seaweeds (due to the input of nutrients caused by the sewages) and the competition with invasive species like Spartina anglica and the Japanese wireweed (Sargassum muticum), to the physical damage due to traffic of human vehicles on the meadows (including the trucks used to serve the aquaculture facilities), worm dredging for bait and even the trampling caused by horses.
In order to fill the gaps in the knowledge of distribution and conservation status of the seagrass beds in Ireland, last June Coastwatch has launched a Seagrass Campaign to raise awareness for the values and plight of seagrass, help citizens find their nearest seagrass lawns and meadows and join forces to protect them. This campaign comes after 10 years of seagrass recordings carried out during the annual Coastwatch autumn shore surveys, and after the national study funded in 2019 by the Marine Unit of the Department of Housing and performed by a qualified Coastwatch team to verify and map these seagrass reports. Despite the challenges involved in the finding and correct identification of the seagrass species, over the years the Coastwatchers have helped find new seagrass bed locations not registered on official maps and follow the expansion or decrease of the meadows that were already known.
The results of the work carried out so far by the citizen scientists involved in the seagrass bed mapping campaign were presented during an online workshop held on the 15th of December and moderated by the Coastwatch representatives Karin Dubsky and Bernadette Connolly. Some brilliant stories of discovery, monitoring and protection of the major seagrass beds mapped along the coasts of the lower half of the island of Ireland were reported by some Coastwatch citizen scientists. In particular, the case studies showcased refer to the seagrass beds around Dublin area (e. g. Rogerstown and Malahide estuaries, Baldoyle Bay and even Dublin city), in Wexford nearby Kilmore Quay, in Bantry Bay (Co. Cork), along the Atlantic side of the tombolo in Fenit island (Co. Kerry) and the newly discovered Zostera bed observed by a swimmer near Quilty (Co. Clare).
The workshop acted also as a platform for citizen scientists and seagrass experts to discuss what are the needs to be addressed to further protect these important marine ecosystems in Ireland. A few important directions have been highlighted, like the need for proper signage in the areas where the seagrass beds are identified to inform the public about them, the importance for the Coastwatchers to inform all possible stakeholders (e. g. local authorities, EPA, National Biodiversity Data Centre) about the discovery of new seagrass beds or changes occurred in the beds already known, the opportunity to liaise with other organisations like e. g. Seasearch Ireland to expand the extent of the study about distribution and conservation status of the subtidal seagrass beds, the demand to control the sources of anthropic pressure that threaten the coastal habitats and so create a management framework aimed at mapping and protecting the Irish seagrass beds, and the need to produce educational material to bring knowledge about the seagrass ecosystems in the schools.
The celebration of the results of the Coastwatch citizen science search for seagrass obtained so far will continue with a second workshop on World Wetlands Day on the 2nd of February 2022 that will focus on case studies from the upper half of the island, including Northern Ireland. In the meantime, whoever wants to join this invaluable effort to protect and know more about the Irish seagrass meadows can visit the Coastwatch Seagrass Survey 2021 to learn how to contribute.