© 2006 International Council for the Exploration of the Sea
The influence of offshore windpower on demersal fish
a Department of Zoology, Stockholm University S-106 91 Stockholm, Sweden
b Department of Biology and Environmental Science, Kalmar University S-391 83 Kalmar, Sweden
*Correspondence to D. Wilhelmsson: tel: +46 702 535365; fax: +46 8 167715. e-mail: dan.wilhelmsson{at}zoologi.su.se.
A significant expansion of offshore windpower is expected in northwestern Europe in the near future. Little is known about the impacts it may have on the marine environment. Here, we investigate the potential for wind turbines to function as artificial reefs and fish aggregation devices (FADs), i.e. whether they would locally increase fish densities or alter fish assemblages. Fish communities and habitat composition were investigated using visual transects at two windpower farms off the southeastern coast of Sweden, central Baltic Sea. Fish abundance was greater in the vicinity of the turbines than in surrounding areas, while species richness and Shannon–Wiener diversity (H') were similar. On the monopiles of the turbines, fish community structure was different, and total fish abundance was greater, while species richness and diversity (H') were lower than on the surrounding seabed. Blue mussels and barnacles covered most of the submerged parts of the turbines. On the seabed, more blue mussels and a lesser cover of red algae were recorded around the power plants than elsewhere. Results from this study suggest that offshore windfarms may function as combined artificial reefs and fish aggregation devices for small demersal fish.
Keywords: artificial reefs, biodiversity, fishery, Gobidae, human disturbance, marine protected area, wind power
Received 30 March 2005; accepted 3 February 2006.