Deployment of foundations and stones including scour protection around the foundations were conducted between the autumn 2002 and the spring 2003. Surveys in October 2003 showed that a fouling community of common mussels, barnacles and macroalgae and associated mobile species of crustaceans and fish was developed during the first reproductive season.
Common mussels and barnacles were the quantitatively dominant organisms and the biomass on the vertical shafts was about ten times higher than on the stones. The biomass was uniform independent of direction (W, E, N and S) but changed due to a decline in barnacles and mussels with increasing depth.
The community of macroalgae was dominated by redalgae. The diversity and biomass increased with depth and was about two times higher on stones than on shafts probably due to a less intensive competition for space and a reduced wave action at greater depth. An analysis of the biomass of macroalgae in relation to direction was inconclusive and further analysis must await renewed surveys of the development of macroalgae.
The biomass and abundance of invertebrates and the biomass of macroalgae on the shaft and stones was reduced at the transformer station compared to the turbines. The seabed work and the traffic have been more intense around the transformer due to additional deployment of connecting cables on the seabed. The associated sediment spill of the extra earthwork and re-suspension of sediment caused by the propellers of the ships may have hampered the settling and growth of organisms and reduced the biomass and abundance of the fouling community in the first reproductive season.