Evidence for the effects of decommissioning man-made structures on marine ecosystems globally: a systematic map

Abstract Background Many marine man-made structures (MMS), such as oil and gas platforms or offshore wind turbines, are nearing their ‘end-of-life’ require decommissioning. Limited understanding of MMS decommissioning effects currently restricts the consideration alternative management possibilities, often leaving complete removal only option in certain parts world. This evidence-base describes ecosystem whilst place following cessation operations, with a view to informing decision-making related potential Method The protocol used create this map was published priori. Systematic searches published, literature English were conducted using three bibliographic databases, ten specialist organisational websites repositories, one search engine, up early 2021. A total 15,697 unique articles identified potentially relevant our research questions, which 2,230 screened at full-text level. Of that subset, 860 met all pre-defined eligibility criteria. further 119 through “snowballing” references from reviews. final database consists 979 articles. For each article included, metadata extracted for key variables interest coded into database. Review findings vast majority eligible presence (96.2%), while just 5.8% considered Overall, mainly artificial reefs (51.5% articles) but increasingly (22%), shipwrecks (15.1%) (13.1%). Studies distributed globally, focused on United States, single countries within Europe, Australia, Brazil, China, Israel; 25 studies spanned multiple countries. Consequently, bulk North Atlantic (incl. Gulf Mexico, Sea, Mediterranean Sea) Pacific Oceans. 12 had global scope. reported fish (53%) invertebrates (41%), disproportionately biological (81%) ecological (48%) impacts. Physico-chemical (13%), habitat (7%), socio-cultural economic (4%) functional (8%) outcomes have received less attention. number has been increasing since ca. 2012 remains noticeably low. mostly focus infrastructures USA (Gulf Mexico) Northern Europe (North Sea), covering 9 different options. Conclusions systematic map, first its kind, reveals substantial body peer-reviewed evidence relating sea impacts, considerable bias toward over abiotic socio-economic outcomes. extremely limited direct effects, likely driven least part by international policy preventing range options beyond removal. Despite impacts continuing grow exponentially 1970s, gaps support best practice developing consider environmental, social effects. Relevant is required generate greater those areas ensure deliver optimal