From an economics perspective, Harnessing our Ocean Wealth (HOOW) – the integrated marine plan for Ireland (2012), is all about maximising the net benefits to society from the use of our substantial marine resources. Previous reports by the SocioEconomic Marine Research Unit (SEMRU) of the Whitaker Institute in NUI Galway have provided an in-depth analysis of the economic importance of the Irish ocean economy. The direct economic value of Ireland’s ocean economy was estimated to be worth €1.8 billion or approximately 0.9% of GDP in 2016. The maritime sectors were also estimated to provide employment for approximately 30,000 individuals. These bi-annual ocean economy reports provide a first order understanding of the economic importance of our seas around us but the economic contribution of the oceans is still undervalued if the many other marine ecosystem services from which we benefit are not considered. For example, the oceans are known to produce half of the oxygen in the atmosphere and absorb 30% of all CO2 emissions; they are a key source of food and play key roles in the mediation of waste and in the provision of recreational opportunities. This report therefore is focused on the ecosystem service benefits that society receives from Ireland’s marine environment, complementing previous work on the Irish ocean economy