It has been widely acknowledged that a global change in energy production, from fossil fuels to renewable sources, is required in order to reduce carbon dioxide outputs and help mitigate anthropogenic climate change. The UK is recognised as having one of the largest practical marine energy resources in Europe, including ‘wet renewables’ energy sources; tidal-stream and wave energy. Scotland, as well as having some of the best marine energy resources, also holds internationally important numbers of breeding seabirds. Both wave energy and tidal stream devices have the potential to place a new anthropogenic pressure on already declining seabird populations. Wet renewables are predicted to impact seabird populations through collision, disturbance, habitat loss and changes to food availability. However, few devices have been deployed to enable monitoring of impacts and there have been few studies of the ecological implications and magnitude of any impacts to these populations. The aim of this thesis is to address key knowledge gaps relating to our understanding of seabird ecology in high-energy marine environments, specifically exploring spatial, temporal and habitat drivers for their use of these areas. This is to help expand the scientific basis used to assess the impacts of marine renewable energy devices on marine birds. This thesis also aims to increase our understanding of bird survey requirements for wet renewable energy schemes to help develop methods for environmental impact assessment. Chapters 2, 3 and 4 demonstrate that marine birds show differing spatial and temporal patterns of abundance and behaviour within high-energy marine environments. By using shore-based vantage point methods in three high-energy areas in the Northern Isles, I explore some variations in vantage point methods. Chapter 5 provides the most extensive and up-to-date review of diving and foraging behaviour for UK marine bird species. I identify knowledge gaps including the species and parameters for which there are a paucity of studies. I demonstrate a more robust approach to data collection in these high-energy tidal stream, which can shed insight on how they are being used by marine birds, while the diving and foraging behaviour synthesis provided many of the values that are required to undertake underwater collision risk modeling. It is hoped that developers can adopt the approaches identified here, which will improve the accuracy of their assessments and improve monitoring of any potential impacts.