Case-dependent impacts of offshore wind farms on ecosystems: A systematic review and meta-analysis

Abstract

The need for diversification of energy sources is driving the expansion of offshore wind farms, which is, in turn, amplifying their impact on marine ecosystems. Understanding the impact of different wind energy associated activities on ecosystems is crucial for developing effective management strategies that balance the benefits of offshore wind energy production with the risks to biodiversity and ecosystem functioning. The present work systematically reviews (PRISMA), critically assesses, and synthesizes in meta-analyses evidence of impacts from activities and associated pressures of offshore wind energy production. A total number of 129 scientific publications investigating the ecological impacts of offshore wind farms in the period from 2003 to 2024 were collated. Almost three-quarters (74 \%) of the identified publications were focused on the northeast Atlantic, where installations are the most abundant. The introduction of novel habitat was the most frequently reported pressure associated with the presence of offshore foundations. The most common impacts were reported on seabirds and cetaceans, with high agreement in the literature of a negative impact during both the operational and installation phases. The results highlighted that only around one third of all theoretical interactions between ecosystem components and activities were addressed. The impacts from offshore activities linked to transmission cable installation and operation, as well as routine maintenance, and decommissioning in general, were least studied. This gap is especially relevant considering the prospects for already established offshore wind farms and the expected industry expansion. The visual and detailed synthesis of evidence is a valuable summary for decision-makers, practitioners, developers, industry and researchers informing the offshore wind sector. Generalisable impacts can directly inform decisions; while monitoring and future research can be prioritised by context dependent impacts and knowledge gaps.