Ireland's State of the Environment Report 2024

226 Chapter 9: The Marine Environment Bathing water The Bathing Water Quality in Ireland Report for 2023 (EPA, 2024a) shows that the water quality at most of Ireland’s bathing waters met or exceeded the appropriate standards: 77% of bathing sites had ‘excellent’ water quality, while 97% met the minimum standard. This represents an improvement since the EPA’s 2020 State of the Environment Report period, when 95% of waters met the criteria. It is also higher than the current EU average of 96% (EEA, 2024). The number of designated bathing areas has slightly increased also, from 147 in 2019 to 148 in 2023; the public can suggest new bathing waters to local authorities for designation each year. 3. Drivers, pressures and impacts Marine fisheries Ireland’s marine area is an extensive resource for seafood production. The value of fish and shellfish landed in Ireland was €507 million in 2022 (BIM, 2023a). However, fishing continues to be the primary threat to ecosystem health despite a decrease in fishing pressure since the 1990s (ICES, 2022b). The health of fish and shellfish populations is assessed under the MSFD. These assessments indicated that GES was achieved for 29 stocks (17%) of fish and shellfish assessed but not for 46 stocks (26%), with the environmental status of 99 stocks (57%) currently unknown (DHPLG, 2020). Slightly fewer stocks are achieving GES now than in 2020, while the number of unknown stocks remains the same. Apart from the effects of the removal of targeted stocks, fishing practices can have an impact on the marine environment through the disturbance of seabed habitats and incidental by-catch (OSPAR, 2021c; ICES 2022a). The use or location of nursery and feeding habitats is still poorly understood, and many benthic (i.e. seabed) habitats, including reefs, are thought to have been severely damaged by bottom-contacting fishing gear. The MSFD status assessment of seabed disturbance shows that the extent and distribution of physical disturbance pressures on the seabed are significant (DHLGH, 2024b). Analysis of bottom mobile fishing data from 2010 to 2015 showed physical disturbance to be widespread, occurring to some degree in 64,865 km 2 (OSPAR Region III of Ireland’s Marine Reporting Unit); some 13% of Ireland’s reporting area. By-catch of mammals (in particular harbour porpoise, common dolphin and grey seals), seabirds and vulnerable species 3 Ocean Heat Content (OHC) – the sum of the heat energy stored in the ocean. of fish including elasmobranchs (sharks, rays and skates) remains a significant pressure (ICES, 2022c; Taylor et al. , 2022). All sectors, including fisheries, are required to contribute to Ireland achieving its targets to reduce greenhouse gas emissions. Emissions arising from fuel use by the Irish fishing fleet, reported as an average of 1.03 tonnes carbon dioxide (CO 2 ) equivalent per tonne of fish landed, are low compared with the global average emissions of the seafood sector (1.7 t CO 2 eq/t) and those of other food-producing sectors (BIM, 2023b). Ocean warming, sea level rise and ocean acidification The ocean has absorbed more than 90% of the additional heat due to greenhouse gas emissions from human activities over the last five decades. It also absorbs about a quarter of annual anthropogenic carbon dioxide emissions to the atmosphere (von Schuckmann et al. , 2020; Friedlingstein et al. , 2022). This has mitigated the severity of climate change effects but has caused changes to the physical conditions and chemistry of the oceans that now threaten marine ecosystems and the services they provide (Wåhlström et al. , 2022). Sea level rise has been accelerating, with a global mean sea level rise of more than 9 cm since 1993, primarily attributed to melting ice and thermal expansion of the oceans. Since the 1990s, satellites have shown increased rates of sea level rise with rates around Ireland of 2-3 mm per year, in line with global trends (Cámaro García and Dwyer, 2021; McCarthy et al. 2023). Ireland also has a high-energy wind and wave climate. The coastal infrastructure and communities are under increasing threat from extreme sea levels, including storm surges, due to sea level rise and increased storminess (McCarthy et al. , 2023). Global sea surface temperature increased at a rate of approximately 0.016°C per year from 1993 to 2020 (Figure 9.8), equating to an increase of approximately 0.43°C worldwide (von Schuckmann and La Traon, 2022). Ocean heat content 3 continues to increase, and marine heatwaves are becoming more intense and frequent (Cheng et al. , 2022; IPCC, 2023; Nolan et al. , 2023). The mild Irish climate is dominated by the Atlantic Meridional Overturning Circulation or Gulf Stream system. A weakening of the Atlantic Meridional Overturning Circulation is considered very likely this century and is a large source of uncertainty in climate models (McCarthy et al. , 2023).