In 2024, Ireland’s Marine Ecosystems covered more than 71 million hectares, an area more than 10 times larger than our land area.
More than half (57.7%) of our Marine Ecosystems are Deep-Sea Ecosystems, which extended to more than 41 million hectares in 2024.
In 2024, Continental & Island Slope ecosystems, characterised by a steep decline from the edge of the continental shelf to the deep ocean floor, covered 21.3% of the marine area, more than 15 million hectares.
Sublittoral Sediments, or seabed dominated by sediments such as sand or gravel in the sublittoral zone, which extends from the low-tide mark to the upper edge of the continental (or island) slope, covered 19.9% of the marine area, more than 14 million hectares.
Kelp Forests and Seagrass Meadows & Beds, covered more than 38,300 hectares in 2024.
In 2024, Coral Reefs were present across more than 70,000 hectares, which was almost half of the 152,600 hectares covered by naturally occurring ecosystems known as Biogenic Reefs & Animal Forests.
Man-made structures and modified ecosystems, including fish farms and areas of seabed mining and dumping, covered 12,000 hectares, less than 0.1% of the marine ecosystem accounting area in 2024.
This release presents the first national map of Ireland’s marine ecosystems, expressed in a new EU Ecosystem Typology and designed to align with the terrestrial/transitional ecosystem extent accounts published by the CSO. The purpose of the map is to provide a consistent baseline for marine ecosystem extent that can be integrated with terrestrial accounts, enabling a complete land–sea picture in line with the SEEA Ecosystem Accounting framework. By adopting a common classification system and a one-hectare grid structure shared with terrestrial accounts, the map creates a foundation for statistical reporting.
The CSO would like to acknowledge the contribution of Darragh Corcoran, who produced this work in collaboration with the Ecosystem Accounts team, the Marine Institute, and SEMRU, University of Galway as part of a statistical collaboration under Section 11 of the Statistics Act (1993). Darragh's research was supported by the Marine Institute through the Cullen Scholarship Programme, funded under the Marine Research Programme with the support of the Government of Ireland.
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Statistician's Comment
The Central Statistics Office (CSO) has today (15 October 2026) published Ecosystem Extent Accounts - Marine 2024.
Commenting on the results, Nova Sharkey, Statistician in the Ecosystem and Agriculture Accounts Division, said: “This release presents the first national map of Ireland’s Marine Ecosystems classified according to a new EU Ecosystem Typology, and gives us a greater insight into the range of ecosystems present in our ocean. Ireland’s Marine Ecosystems cover 71.3 million hectares, an area more than 10 times larger than our land area.
Some of these ecosystems are more familiar to us than others. Near the shore, ecosystems dominated by marine macrophytes such as seaweeds, including Kelp Forests and Seagrass Meadows & Beds, covered 40,400 hectares in 2024. Coral Reefs extended to more than 70,000 hectares, which was almost half of the 152,600 hectares covered by Biogenic Reefs & Animal Forests.
Man-made structures and modified ecosystems, including fish farms and areas of seabed mining and dumping, covered 12,000 hectares, less than 0.1% of the marine ecosystem accounting area in 2024.
More than half (57.7%) of our Marine Ecosystems are Deep-Sea Ecosystems, which extended to more than 41 million hectares in 2024. Continental & Island Slope ecosystems, characterised by a steep decline from the edge of the continental shelf to the deep ocean floor, covered the next largest proportion, at 21.3% of the marine area, more than 15 million hectares. Sublittoral Sediments, or seabed dominated by sediments such as sand or gravel in the sublittoral zone, which extends from the low-tide mark to the upper edge of the continental (or island) slope, covered 19.9% of the marine area, more than 14 million hectares."