The role and impact of oil and gas structures on the connectivity and metapopulation dynamics of tropical reef species

Offshore oil and gas (O&G) structures exist in nearshore and offshore marine environments globally, yet our understanding of their ecological implications is poorly understood, especially when it comes to decommissioning these structures at the end of life. Specifically, the influence of these structures on dispersal-based connectivity and population persistence of associated species has yet to be quantified. In this study, we provide insights into the ecological implications of O&G structures on the North West Shelf (NWS) of Western Australia. Specifically, we examine their impact on local and regional population connectivity patterns and metapopulation dynamics for two fish species and a coral. By integrating biophysical modeling, network analysis and metapopulation models, we estimate the contribution and impact of both O&G structures and natural reef systems in this complex seascape. Our findings indicate that collectively the reefs in this system contribute as the main sources of larval export and O&G structures contribute as destinations, with a higher import of larvae. These structures could also act as local stepping-stones, enhancing the ecological connectivity among reef subpopulations. Overall, O&G platforms and wells, as included in the model, do not have a significant impact on regional metapopulation dynamics for the reef species explored in this study. Knowledge gained from this research will inform regional spatial planning for decommissioning offshore infrastructure.