Effect of the Horns Rev 1 Offshore Wind Farm on Fish Communities: Follow-up Seven Years after Construction

Deployment of offshore wind farms is rapidly expanding in Denmark and in the rest of Europe, due to a high demand, both economically and politically, for renewable energy. At present 12 offshore wind farms are in operation in Danish waters. Offshore wind farms are often placed in relatively shallow waters (<20 m) due to engineering and economic constraints. These shallow areas are often biologically highly productive and function as important nursery and feeding grounds for a number of fish species. The establishment of wind farms is hypothesized to positively impact fish abundance and fish community structures by increasing habitat heterogeneity and through exclusion of trawling activities within the wind farm area. This report presents results from a field experiment in a demonstration study site (Horns Rev Offshore Wind Farm 1), one of the world’s largest offshore wind farms. The construction of this farm, which is composed of 80 wind turbines and located in the North Sea 14-20 km off the western coast of Denmark, at Blaavands Huk, was completed in late 2002. The aim of the study was to analyze changes in fish community structure, spatial distribution and changes in sandeel assemblages due to the establishment of the wind farm.