After years of being exposed to adverse weather, the rotor blades of offshore wind farms experience wear and erosion, which leads to the release of significant amounts of particle emissions into the environment. A research team from the Alfred Wegener Institute has studied how these particles affect blue mussels—a species being considered for aquaculture in multi-use wind parks. Their recent findings, published in the journal **Science of the Total Environment**, highlight how these mussels absorbed metals from the coatings of the rotor blades, and delve into the possible physiological impacts.
In a laboratory pilot study, researchers investigated how emissions from rotor blades might impact the blue mussels’ physiology. They ground the rotor blade material into particles small enough for the mussels to ingest. “We subjected the mussels to different levels of particle concentrations and then sampled them after specific exposure times,” says Dr. Gisela Lannig, eco-physiologist and project lead at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). They also conducted physiological assessments to observe any metabolic shifts in the mussels, and tissue samples were analyzed for inorganic elements, especially metals, at the Helmholtz Centre Hereon labs.
“In our worst-case scenario, the blue mussels were exposed to high concentrations of particles for up to 14 days in a row. The mussels showed a noticeable uptake of metals, particularly barium and chromium,” notes Dr. Daria Bedulina, a fellow eco-physiologist and postdoc at the AWI. “While there were no definitive outcomes from the physiological tests, the metabolic changes observed suggest potential short-term impacts on their neuroendocrine functions and amino-acid metabolism. This indicates the need for further research, particularly concerning the long-term implications for mussels.”
Alongside the AWI and Hereon, the study involved contributions from researchers at the Fraunhofer Institute for Wind Energy Systems (IWES), who provided rotor blade materials and insight into the quantities of eroded materials. The findings underscore that offshore wind farms present a new human-made stress on marine environments: the study warns that the polymer particles emitted from rotor blades, due to their degradation and erosion, should not be ignored. Blue mussels, like those examined in this study, are crucial to coastal ecosystems, providing habitats and breeding grounds for various marine species, enhancing biodiversity, and maintaining water quality as filter feeders. However, these mussels can accumulate microplastics and pollutants in their tissues.
“For the multi-use of offshore wind parks to cultivate mussels for human consumption, thorough investigations combining lab experiments and field studies are urgently needed to rule out any potential risk to human health,” explains Gisela Lannig. However, she adds that the current pilot study does not offer a complete and reliable assessment of the risks posed by offshore wind farms to marine ecosystems. Achieving this requires extensive short-term and long-term studies, complemented by a holistic approach that evaluates multiple biological parameters and life stages. As the expansion of renewable energy sources and the multi-use of offshore wind parks for aquaculture is both necessary and beneficial, such research is critical.
