Early biofouling colonization stages: Implications for operation and maintenance planning in marine renewable energy projects

Background: Marine biofouling is a threat to industries working in the marine environment, representing enormous costs associated with equipment impairment and loss of performance. In the Marine Renewable Energy (MRE) and other maritime sectors which operate at sea for long periods, an important aspect of biofouling is related to the type and frequency of maintenance. Methods: This study investigated important parameters of macrofouling (for example composition, including the presence of non-indigenous species, thickness, and weight) from communities growing on small-scale wave energy components in marine conditions. The trials were performed during short periods of submersion (one to eight weeks) in the seasons when the colonisation process should be most intensive (spring, summer, and autumn). Furthermore, the frictional resistance forces generated to scrape the biofouling from those artificial components were investigated. Results: Overall, results show that while biofouling growth in early colonization stages might not present great detrimental effects to wave energy components, although marine corrosion and the settlement of non-indigenous species (NIS) should be factors of concern. Conclusions: It is suggested to perform biofouling-related maintenance activities after the peak of maximum growth and reproduction (during the warmer seasons in temperate to cold environments) to reduce the number and frequency of activities. NIS can be detected very early in the colonization process, highlighting the importance of biofouling monitoring and the implementation of biosecurity risk assessment plans early in the operational stage of MRE projects.