EPA - Ireland's Environment, An Integrated Assessment - 2020

Chapter 8: The Marine Environment Figure 8.3  Pressure map of fishing efforts in Irish waters on the left (Gerritsen and Kelly, 2019). OSPAR Region III is shown on the right Aquaculture Aquaculture is an important sector that can potentially impact the marine environment through a number of pressures. In Ireland, aquaculture mainly consists of shellfish (oysters and mussels) and finfish (mostly salmon) farms. Ireland has 64 designated shellfish growing areas, which have specified water quality requirements to support shellfish life and growth. The Irish aquaculture output in 2017 was worth €208.4 million, with production relatively constant over the last decade. Aquaculture can impact the marine environment through escaped farmed salmon, spreading of disease to native populations, disturbance to and displacement of fish, shellfish, birds and other wildlife populations, and water pollution and is considered a pressure for a number of protected habitats (Bresnihan, 2016; NPWS, 2019). Recent Irish research has indicated that wild Salmon smolts (young Salmon which are ready to migrate to the sea) with mild-to-moderate lice infestations from coastal aquaculture may show greater sensitivity to ocean warming and fewer returns to rivers in following years (Shepard and Gargan, 2020). Pollution risks to shellfish water and environmental health aspects are discussed in Chapter 14. Climate Change and its effects on the Marine Environment Since 1994, temperatures in Irish coastal waters have increased at a rate of 0.6°C per decade. Climate change can impact ocean and coastal processes through changes to their, physico- chemistry and temperature and have effects on ecosystem components including valuable commercial fish stocks. Climate change impacts on the coastal and marine environment manifest through a shift in the baseline conditions for ecosystem structure (coastal erosion, sea level rise), physico-chemical conditions (temperature and ocean acidification) and the transport of anthropogenic pressures, such as nutrients, from land-based sources. These shifts can have very clear, and in some cases, irreversible impacts on marine ecosystems including the organisms that live in them. 201