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

Offshore oil and gas structures are continuing to be placed in nearshore and offshore marine environments within Australia, yet our understanding of the ecological implications is poorly understood. Over the course of implementation to decommissioning, the establishment of biological communities on and around oil and gas structures raises questions as to whether they function as habitats providing net benefits or loss to nearby reef populations. More specifically, how these structures influence the dispersal and persistence of commercially and ecologically important species, including invasives. In this study, I provide insights into the ecological implications of oil and gas structures to surrounding coral reef connectivity and the metapopulation dynamics. This study integrates biophysical modelling, network analysis and metapopulation models, to estimate implications of oil and gas to existing natural coral reef habitat dynamics. Our results suggest that across metapopulations, O&G structures contribute very little to surrounding reef populations, demonstrating larval movement mainly occurs from reefs to oil and gas. Results also suggests many O&G structures likely act as important stepping-stones enhancing ecological connectivity among distant reef populations, and may have impacts on range-expansion therefore, facilitating the spread of economically important species, including invasives. Conclusions from this study suggest that given O&G structures have only slight implications to larval connectivity and metapopulation dynamics of reef-associated species, in situ abandonment or partial removal may be the best/optimal path forward for decommissioning. Oil and gas decommissioning bodies and marine protected area managers would benefit from understanding oil and gas implications to larval dispersal, therefore leading to more informed decision making regarding complete removal, partial removal, or in situ abandonment of structures, and conservation priorities within regions where these structures exist.