23rd May 2023

Carlingford eelgrass beds under threat from invasive Cordgrass?

On the Southwestern shores of the Mourne Gullion Strangford aspiring UNESCO Global Geopark Carlingford Lough Marine Protected Area (MPA) is a transboundary sea lough located on the border of Northern Ireland and the Republic of Ireland, on the Newry estuary.

The MPA supports a variety of important habitats and species, including of internationally important populations of light-bellied Brent geese (Branta bernicla hrota); a winter migrant that feeds mostly on eelgrass.

Unfortunately, the eelgrass beds of Carlingford Lough may be under threat from an invasive non-native species (INNS) known a common cord-grass Spartina anglica.

Spartina anglica colonises a wide range of substrates, from very soft muds to shingle, in areas sheltered from strong wave action. It was extensively planted in Northern Ireland in the 1940s as an aid to stabilisation of intertidal mudflats and dunes; and to enable land-reclaim.

Spartina Anglica Image credit: DAERA

Spartina Image Credit: DAERA

The issue now is that it too readily colonises open mudflats and consequently has spread rapidly around the coast. Spartina anglica  is now considered a threat as it out-competes and replaces native eelgrass (Zostera marina), on which the light-bellied brent goose depends (Branta bernicla hrota).

As a result, attempts have been made to control cordgrass at several sites, other than in  Carlingford Lough, over many years, but where control has had some success, eliminating it has been largely unsuccessful.

The salt marsh habitats in Carlingford Lough are currently monitored by both the Department of Agriculture Environment and Rural Affairs (DAERA) at Mill Bay and Carlingford Bay and the National Parks and Wildlife Service (NPWS) in the Republic of Ireland. 

The AONB & Geopark team of Newry Mourne and Down District Council are delivering projects across the Geopark to protect habitats and species. The aim of the project is to review current information on the status of Spartina anglica in Carlingford lough and conduct a field survey to identify whether it has spread since the most recent surveys. This will provide evidence for further assessment and future management to improve control.

Conor Mallon, Director Enterprise Regeneration and Tourism said “Our native biodiversity is constantly under threat from invasive non-native species. It is very important that we, as council leaders, and as a community do our bit to prevent the spread of invasive species. There are simple steps that we can all take to do this. Report all sightings, know what you are growing in your pond or garden, do not deliberately introduce an invasive species, and if you are out on the water follow the principles of ‘Check Clean Dry’”.

Seagrass beds

Eelgrass beds

For more information please visit:

– ID Guide –

general species info –

Information on Check Clean Dry

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