The Marine Renewable Energy Strategic Framework for Wales (MRESF) provides for the sustainable development of marine renewable energy in Welsh waters. Phase 2 of the Assessment of Risk to Marine Mammals from Underwater Marine Renewable Devices in Welsh Waters provides additional baseline characterisation information on the occurrence and use of Welsh waters by marine mammals to ensure that marine renewable energy developments occur with as little adverse environmental impact as possible. Cetaceans, which are European Protected Species (EPS) and seals, for which Special Areas of Conservation (SAC) have been designated close to and encompassing areas of tidal rapid in Wales, are groups of particular interest, and for both there are concerns that they may suffer collisions with rotating turbine blades. In addition, turbines may act as barriers to movement, especially if many devices are deployed together in arrays. Marine mammals are often seen within tidal rapids and there are some observations that suggest that these can be important areas for them. However, our understanding of marine mammal distributions and behaviours within high tidal energy areas is actually very poor for two reasons. In the first place, tidal rapids are an extremely difficult environment in which to conduct research, especially when currents are running strongly, which is exactly the time when the potential risk of collision with turbines is greatest. Consequently, very little relevant quantitative data has been collected from these habitats. The second consideration is that these areas are a very small part of the range of any marine mammal species and are so unusual, that it is not possible to extrapolate from observations of densities or behaviour made on a much larger spatial scale outside these areas. The purpose of the project reported here was to undertake directed research on marine mammals at tidal rapid sites in Wales and to collect data relevant to assessing risks if tidal turbines were installed at these sites. As this was very much a new area of investigation a variety of research approaches were trialled and some new techniques were developed and tested.
The Approach to Sustainable Development Report presents the final outputs of the Marine Renewable Energy Strategic Framework (MRESF). The MRESF will be an essential management tool for the sustainable development of wave and tidal energy in Wales.