Name: Lena Bergstrom
As in many other countries, an expansion of wind power is expected in Sweden during the coming decades. The expansion is driven by rising prices on electricity and the need for an increased production of renewable energy. Since wind conditions at sea are good and relatively constant, several off-shore wind farms are planned in Swedish waters. Offshore wind power with a total effect of about 2500 MW has been granted permission and an addi-tional 5500 MW are being planned for. Examples of granted projects are Storgrundet with an effect of 265 MW, Stora Middelgrund with an effect of 860 MW and Kårehamn with an effect of 48 MW. The largest offshore wind farm in Sweden today is Lillgrund in Öresund, with its 48 turbines with an installed effect of 110 MW.
Prior to this expected expansion, it is important to investigate the environ-mental impact of offshore wind power, and how possible negative effects can be minimized. This synopsis about the impact of wind power on the marine life in Swedish waters is based on more than 600 studies, most of which are scientific articles, but also reports by companies and authorities
Vindval- collaboration between Swedish Energy Agency and Swedish Environmental Protection Agency
The information presented in the synopsis can serve as a basis for environ-mental impact assessments and in planning and approval processes at local, regional and national levels. It can also provide knowledge to all who want to know more about the biological aspects and effects during the construction and establishment of offshore wind power in Swedish marine areas.
The electric cables leading from a wind turbine generates a magnetic field that decreases with distance from the cable. The expected effect on most fish species is low, but since the effect is ongoing throughout the entire operational stage, the risk should be considered in areas that are important to migrating fish species. No studies have been found that show how electromagnetic fields affect marine mammals. The few studies that have been found on invertebrates indicate that the electromagnetic fields around common transmission cables have no effect on either reproduction or survival.
Effects on Fish: The expected effect of electromagnetic fields on most fish species is low, but the impact will continue throughout the operational phase and the knowledge base is relatively weak. Due to the increased use of electric cables in the marine environment, the risk of cumulative effects should be taken into account.
Effects on Marin Mammals: There is very little data on whether seals and porpoises can detect electric and magnetic fields. Recent results indicate that at least one dolphin specie is aware of electric fields (Czech-Damal, 2011). Whether this also applies to porpoises, harbour seals and grey seals, have not yet been studied.
Effects on Bethic flora and fauna: Establishment of wind farms, which mostly occurs on sandy or muddy bottoms, leads on the Swedish west coast and in the Baltic Proper to a highly localized increase of sessile invertebrates on the turbine towers and erosion protections. Which species that will dominate depends primarily on the salinity of the sea area. The total addition of hard substrate is small and the impact and increased biomass is assessed to be mainly local, around foundations and erosion protections.
Bergström, L.; Kautsky, L.; Malm, T.; Ohlsson, E.; Wahlberg, M.; Rosenberg, R.; Capetillo, N. (2012). The Effects of Wind Power on Marine Life - A Synthesis. Report by Vindval. pp 92