Short Science Summary: Offshore Wind Farms as Stepping Stones for Non-indigenous Species

One of the most important effects of offshore wind farms is the unintentional provision of a new habitat which invariably is rapidly colonized by hard substrate species. Turbine foundations provide hard vertical substrates and, depending on the structure and scour protection used, varying degrees of habitat complexity. These novel surfaces span the full water column from the splash zone to the seafloor, often in areas where comparable natural hard surfaces are absent. Non-indigenous species (NIS) are species that did not occur in a particular geographic region, such as the North Sea, prior to a certain date (e.g., the beginning of the 17th century). They consist of species introduced by human activities outside their natural past or present range (introduced species), and species that spread by their own means (range expanding species) due to rising temperatures or other factors. As ocean sprawl in shallow and coastal waters has favored NIS, there is concern that increasing development of offshore wind farms will accelerate this phenomenon. This summary represents a general overview of the research, produced by WREN under IEA Wind.