These grid data were derived from National Parks and Wildlife Service cetacean surveys within the Irish MSFD area and the EEA-10km GRID. The grid shows the current distribution of Harbour seal (Phoca vitulina) and Grey seal (Halichoreus grypus) in Irish coastal and marine waters. The data were collected for the purposes of 2019 reporting under Article 17 of the EU Habitats Directive. Polygon shapefile showing the 10km grid cell-based current distribution of the Annex II seal species. The following data sources were used to determine their distribution: Morris, C. D. and Duck C. D. (2019) Aerial thermal imaging survey of seals in Ireland, 2017-2018. Report (unpublished) for the National Parks and Wildlife Service of the Department of Culture, Heritage and the Gaeltacht. NPWS (2018) Unpublished data collected during local site surveillance and regional monitoring of Ireland's seal populations along the east-southeast, west-southeast and northwest coasts between 2009 and 2018. Supporting Data: Data collected during the IWDG ISCOPE I and II projects, the IWDG/GMIT Marine Mammals and Megafauna in Irish waters project, the IWDG Ferry Surveys Programme and the IWDG casual and effort-based sightings scheme between January 2005 and January 2011. A single marine mammal observer (or up to three observers, in the case of IWDG ferry surveys) conducted a visual survey effort from research vessels, naval service vessels and commercial ro-ro ferries between 2005 and 2011. Survey effort was conducted either from the ship’s bridge, the monkey island (the roof of the bridge) or from the crow’s nest (R.V. Celtic Explorer). Using an angle board and distances were estimated with the aid of a range-finding stick (Heinemann 1981). Environment data were recorded every 15 / 20 minutes using Logger 2000 software (IFAW 2000). Sightings were also recorded using Logger 2000. Automated position data were obtained through a laptop computer linked to a USB GPS receiver. Survey effort was conducted up to Beaufort sea-state six and in moderate to good visibility. As these were surveys onboard vessels of opportunity, the surveys were conducted in passing mode and cetaceans sighted were not approached. Sightings were identified to species level where possible, with species identifications being graded as definite, probable or possible. Where species identification could not be confirmed, sightings were downgraded (e.g. unidentified dolphin / unidentified whale / unidentified beaked whale etc.) according to criteria established for the IWDG’s cetacean sightings database (IWDG 2013). Observer effort focused on a 90-degree arc ahead of the ship; however, sightings located up to 90 degrees to port and starboard were included. Surveyors scanned the area by eye and using binoculars (typically 10X40 or 8X50). Bearings to sightings were measured. None