Aggregation and feeding behaviour of pouting ( Trisopterus luscus) at wind turbines in the Belgian part of the North Sea

Abstract

A substantial expansion of offshore wind farms in the North Sea has been planned, inducing a growing interest in the effects of these artificial habitats on the marine environment. Numerous researches have been done to consider the possible effects of wind farms. However, to date little research investigated actual effects on the ichthyofauna. This study provides the first insights into the use of the artificial hard substrates by Trisopterus luscus (pouting) at the Thorntonbank wind farm in the Belgian part of the North Sea. Scuba diving operated visual surveys around one wind turbine revealed a distinctly higher pouting population size and biomass (i.e. 22 000 individuals yielding a total biomass of 2700 kg) as compared to the population size present at the soft sediments surrounding the wind turbines. Stomach content analyses further demonstrated the dietary preference for prey species that lived on the turbines (i.e. Jassa herdmani and Pisidia longicornis). Yet, the present study clearly demonstrates that wind turbines built at sea may attract fish populations considerably, possibly related to the enhanced provision of resident food items on the turbines.