Assessing the Impact of Windfarms in Subtidal, Exposed Marine Areas

Marine renewable energy conversion typically takes place at locations characterized by harsh physical parameters that challenge monitoring of the marine environment. These challenges are caused both by the lack of experience on what to expect in terms of impact, but also by a general lack of methods proven suitable for the monitoring of high-energy subtidal marine habitats. Here, the first offshore windfarm to be built in Norwegian waters, a project called Havsul I, is used as a model to provide (i) an overview contrasting the known effects and monitoring methods used at more sheltered offshore windfarms with those expected at a rocky, high energy site; (ii) a description and short assessment of the physical environment (bathymetry, current, wave and wind data) and marine assemblages at the site, (iii) an assessment of five methods used during the baseline study at Havsul I, including sediment grabs, sampling of assemblages from kelp stipes, video mosaics for rocky bottom benthic assemblages, traditional fishing gear for fish community evaluation, and C-PODs for harbour porpoise presence.