Analyzing the metal body burden of turbine-colonizing mussels from North Sea offshore wind farms

Offshore wind farms (OWFs) are a key technology for renewable energy production. In the context of increased deployment of offshore energy infrastructure, it is important to estimate the potential chemical impacts of OWFs on the environment. These include emissions from galvanic anodes made of AlZnIn alloys, which may also contain other elements like Ga, Cd and Pb. The mussel Mytilus edulis is both a dominant colonizer of offshore wind turbine foundations and has a long history of use in environmental monitoring programs. We present a first investigation of metal(loid) mass fractions of M. edulis from OWFs in the North Sea. This dataset provides first information about the uptake of metals by mussels within OWF boundaries and is to our knowledge the first study to present data of mussels originating from OWFs. No noteworthy accumulation of OWF tracers or toxic metals in mussels was detected and mussels do not appear to be a sink for typical OWF-induced metals. Lower metal mass fractions of (toxic) metals of this study compared to literature and monitoring data are related to the geographic distance of OWFs to large coastal contaminant inputs. This is especially relevant for future multi-use scenarios proposing OWF sites for aquaculture. SYNOPSIS STATEMENT: The potential uptake of metals released from offshore wind farms by Mytilus edulis was studied. Measured mass fractions in tissue are not expected to cause negative effects in M. edulis at the current stage.