Generating electricity from marine energy is a globally important industry and forms a vital part of several nations' objectives to decarbonise energy production. In the UK, the resource-rich waters around Scotland have led to world-leading developments of facilities and supporting infrastructure used in deploying and testing wave and tidal energy technologies. A major concern to industries working in the marine environment is biofouling on submerged structures, including energy converters and measurement instrumentation. In this study, marine energy devices, infrastructure, and instrumentation were surveyed to characterise biofouling organisms. Fouling communities varied between deployment habitats; key organisms were identified allowing recommendations for scheduling device maintenance and preventing spread of invasive species. A method to measure biofouling impact on hydrodynamic response is described and applied to data from a wave-monitoring buoy deployed at a test site in Scotland. Results are discussed in relation to measurement accuracy of resources for power generation. Further applications are suggested for future testing in other scenarios including habitats use for extracting tidal energy.