Abstract. Technologies for collaboration within the oil and gas industry, which are referred to as Integrated Operations, challenge traditional geographical, disciplinary, and organisational boundaries. Fuelled by the availability of sensor networks, faster data transfer technologies, shared data exchange formats, and collaborative work flows, Integrated Operations entail difficult transformations at the technological, social, and political levels. We describe and discuss the efforts of a Scandinavian oil and gas company to develop an information infrastructure for real-time subsea environmental monitoring. This accentuates the ongoing controversy among environmental concerns, fisheries, and the oil and gas industry. Theoretically leaning on infrastructuring and, methodologically, on the concept of infrastructural inversion, our analysis specifically targets the evolution of emergent infrastructures. We identify and discuss the increasing degree of entanglement of the infrastructuring process over time by empirically characterizing two concepts: (1) bootstrapping, which is particularly pronounced in the early stages of infrastructure evolution and involves exploring the local feasibility of subsea environmental monitoring methods and devices, and (2) enactment, which is increasingly present in the later stages of infrastructure evolution to weave environmental information into the agenda of heterogeneous oil and gas professionals.