We quantify through simple population-dynamics models the biological growth on wave energy converters (WECs). We also evaluate the effects of the inherently unsteady flow induced by waves and currents on the settlement of various species. Finally, we discuss the impact of the biological growth on the flow pattern around such devices (and consequently on their efficiency) and investigate the influence WEC farms might exert on the marine environment (in particular possible enhancements in kelp vegetation). Our results indicate that biofouling is an issue that should be considered carefully in the design and site selection processes of wave power devices.
Although the outstanding energy resource contained in the oceans, and in particular in ocean waves, has been recognized for some time now, the extraction of wave power is still in developmental stages with many different technologies being currently tested. At the same time, there is an increased interest in sustainable energy resources, which could prompt a significant expansion of large-scale renewable energy installations worldwide in the near future. In this context, the potential impact of wave energy converters installations on the marine environment is an issue of growing concern. This impact is very likely multifaceted: acoustic and electromagnetic pollution, changes in habitats and hydrological conditions, etc. - see for instance Witt et al. (2012) and Langhamer et al. (2010). Indeed, wave energy converters will be integrated in the ecosystem as artificial reefs suitable for algal growth and colonization by many other species but also within larger structures such as kelp forests. Conversely, biofouling on the device would likely impede on the efficiency of power extraction and even the normal functioning of the device. Biofouling is generally defined as the "undesirable" accumulation of fixing organisms (bacteria, plants, algae, or animals) on any structure in contact with water. The biofouling process starts as soon as the object comes into contact with the sea water.