Climate Science and Policy

To inform the sustainable development of offshore wind (OSW) in California, the California Marine Sanctuary Foundation (CMSF), a non-profit with 30 years of experience improving the resilience and stewardship of California’s coastal resources, is developing the Offshore Wind Environmental Monitoring Guidance (EMG) for the California Ocean Protection Council. In support of the EMG, this study reviewed scientific and gray literature and synthesized existing knowledge on fixed bottom and floating OSW’s impacts on marine ecosystems. The primary impacts on marine ecosystems include noise effects, displacement, entanglement and collision with, attraction to, or avoidance of OSW infrastructure, habitat alterations, anthropogenic emissions and pollution, and electromagnetic field (EMF) effects. Identifying knowledge gaps and monitoring priorities is critical for initial OSW development in California. This synthesis reveals that while we have a more developed understanding of OSW's acoustic and EMF impacts on marine megafauna, we lack a similarly complete understanding of OSW’s ecosystem-wide impacts on most taxa.