This chapter discusses the potential negative impacts that an offshore wind farms (OWFs) can have on marine biodiversity and the ways an OWF can increase species abundance, richness and biodiversity to establish whether OWF and Marine Protected Areas (MPAs) can in fact ever co‐exist. It also discusses the future prospects for OWF development that may reduce the initial impact, thereby enhancing their co‐existence. The chapter considers examples where OWFs and MPAs exist in the same place as well as examples of where the existence of an MPA has prohibited or stalled the construction of an OWF. There are three main stages in the life of an OWF: construction, operation and decommissioning. The chapter discusses some of the known effects of OWF noise on marine mammals, such as temporary hearing loss and permanent tissue damage.