Effects of offshore wind farms on marine wildlife—a generalized impact assessment

Abstract

Marine management plans over the world express high expectations to the development of offshore wind energy. This would obviously contribute to renewable energy production, but potential conflicts with other usages of the marine landscape, as well as conservation interests, are evident. The present study synthesizes the current state of understanding on the effects of offshore wind farms on marine wildlife, in order to identify general versus local conclusions in published studies. The results were translated into a generalized impact assessment for coastal waters in Sweden, which covers a range of salinity conditions from marine to nearly fresh waters. Hence, the conclusions are potentially applicable to marine planning situations in various aquatic ecosystems. The assessment considered impact with respect to temporal and spatial extent of the pressure, effect within each ecosystem component, and level of certainty. Research on the environmental effects of offshore wind farms has gone through a rapid maturation and learning process, with the bulk of knowledge being developed within the past ten years. The studies showed a high level of consensus with respect to the construction phase, indicating that potential impacts on marine life should be carefully considered in marine spatial planning. Potential impacts during the operational phase were more locally variable, and could be either negative or positive depending on biological conditions as well as prevailing management goals. There was paucity in studies on cumulative impacts and long-term effects on the food web, as well as on combined effects with other human activities, such as the fisheries. These aspects remain key open issues for a sustainable marine spatial planning.

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“…Additionally, effects should be evaluated across multiple spatial and temporal scales to determine population-level effects on resident fish and macro-invertebrates (Bergstrom et al, 2014;Lindeboom et al, 2015). Many species use large areas during their life span (e.g., egg, larval, juvenile, adult stages), often make long-distance seasonal migrations (Secor, 2015), and therefore small-scale effects (on the scale of individual WEAs) may have additive effects (Bergstrom et al, 2014;Dai et al, 2015) on populations of commercially and ecologically important fish and macro-invertebrates.…”

“…Assessment of the impacts of the location, construction, and energy production of offshore wind farms on fish and macro-invertebrates on the northeast U.S. shelf is in the early stages. However, European countries have been conducting environmental assessments since the early 1990s that have resulted in review articles on the general impacts of, and long-term research needs for, offshore wind farms (Wilson et al, 2010;Lindeboom et al, 2011;Bailey et al, 2014;Bergstrom et al, 2014;Dai et al, 2015;Lindeboom et al, 2015). The reviews have generally concluded there are potentially minor to moderate effects on fish and macro-invertebrate communities.…”

“…The reviews have generally concluded there are potentially minor to moderate effects on fish and macro-invertebrate communities. These effects may result from increased anthropogenic noise and electromagnetic fields, increased turbidity, loss or degradation of existing bottom habitats, gains in hard bottom and structural habitats, and the limitation or exclusion of fisheries (Wilson et al, 2010;Bergstrom et al, 2014;Dai et al, 2015;Lindeboom et al, 2015). These effects all have the potential to modify community structure, including changes in species composition, diversity, and productivity (Bergstrom et al, 2014;Lindeboom et al, 2015).…”

“…These effects may result from increased anthropogenic noise and electromagnetic fields, increased turbidity, loss or degradation of existing bottom habitats, gains in hard bottom and structural habitats, and the limitation or exclusion of fisheries (Wilson et al, 2010;Bergstrom et al, 2014;Dai et al, 2015;Lindeboom et al, 2015). These effects all have the potential to modify community structure, including changes in species composition, diversity, and productivity (Bergstrom et al, 2014;Lindeboom et al, 2015). The reviews highlight the need for before, during, and after construction monitoring to examine ecosystem level effects and the need to continue to track effects over the long term (Lindeboom et al, 2011;Lindenboom et al, 2015).…”

“…The reviews highlight the need for before, during, and after construction monitoring to examine ecosystem level effects and the need to continue to track effects over the long term (Lindeboom et al, 2011;Lindenboom et al, 2015). Recommendations also include the use of multiple gear types to examine the entire ecosystem (Wilson et al, 2010), the examination of population-level effects (Bergstrom et al, 2014;Lindeboom et al, 2015), and the implementation of sampling across large spatial scales (Dai et al, 2015;Lindeboom et al, 2015).…”