Artificial hard-substrate colonisation in the offshore Hywind Scotland Pilot Park

Abstract. Artificial substrates associated with renewable offshore energy infrastructure, such as floating wind farms, enable the establishment of benthic communities a taxonomic composition similar to that naturally occurring rocky intertidal habitats. The size biodiversity impact and structural changes in habitats will depend on selected locations. aim study is assess colonisation zonation, quantify diversity abundance, identify any non-indigenous species present within farm area, well describe epifouling growth between 2018 2020, regards coverage thickness. This article based work undertaken Hywind Scotland Pilot Park, first park established world, located approximately 25 km east Peterhead, Scotland. pilot situated water depths 120 m, seabed characterised predominantly by sand gravel occasional patches mixed sediments. utilised class remotely operated vehicle mounted high-definition video camera, deployed from survey vessel M/V Stril Explorer. A total 41 structures, their sub-components, including turbines substructures, mooring lines, suction anchors infield cables, were analysed diversity, colonisation, zonation. approach provides comprehensive whole structures safe time-saving manner. 11 phyla 121 different taxa observed, macrofauna macroalgae filamentous algae being identified structures. submerged measured 80 m height exhibited distinct patterns Plumose anemones (Metridium senile) tube-building fan worms (Spirobranchus sp.) dominated bottom mid-sections (80–20 m) turbines, while kelp other Phaeophyceae blue mussels (Mytilus spp.) top sections (20–0 m). general increase 2020 was whereas change thickness years more variable.