Recognition and assessment of the dependencies and potential impacts on Biodiversity and Ecosystem Services (BES) combined with their effective management through targeted action plans, results in significant benefits to an oil and gas company. The benefits are cost minimization, improved access to new resources and reputation enhancement. Operating in a BES-responsible manner is particularly significant when conducting exploration and production activities in sensitive environments like the Alaskan North Slope where eni Upstream, through its affiliate Eni US Operating Co. Inc., is the operator of the Nikaitchuq site since 2007.In compliance with eni Upstream BES management practice and oil and gas sector guidelines, BES evaluations are integrated along the Nikaitchuq asset lifecycle. Therefore, the BES assessment and impact mitigation are aligned with the project timeline and periodically updated following the evolution of the operations. This approach enables effective management of BES issues from the exploration phase, through development and production, until decommissioning the project. In 2009, during the development phase, a biodiversity assessment and action plan (BAP) was performed in collaboration with Fauna & Flora International (FFI). The BAP was aimed at assessing and mitigating potential impacts associated with the construction of production and processing facilities. When the Nikaitchuq site transitioned to production, there was the need to align the assessment and the BAP with the new project lifecycle phase. The project transition provided a good opportunity to apply newly developed tools that incorporated the most recent BES conservation concepts and international best practices. This paper illustrates how alignment was achieved and establishes a foundation for the update of the Nikaitchuq BES assessment and the re-design of the BAP from the development phase to the current project lifecycle phase. Relevant changes in the operational, environmental and social context since 2009 were identified; engineering solutions and operational practices implemented to mitigate environmental impacts, and the outcomes of the 2009 BAP monitoring/restoration activities were reviewed and evaluated against the mitigation hierarchy framework.Based on these, BES features potentially impacted by the present Nikaitchuq operations will be identified and prioritized for inclusion into the updated BAP suited for the current operational phase.