The practices noted in this document represent a mixture of “good,” and, in some cases, “best” practice drawn from those that are well known and that have been shown to be effective when used appropriately. However, it should be recognized that “best practice” is constantly evolving and must also be adapted to each specific site and its environment. This document therefore represents a “menu” of sound biodiversity conservation practices from which can be chosen the most appropriate measures that fit the operational and geographic setting. The impacts and related preventative and mitigative measures discussed cover the entire project lifecycle, with the exception of the pre-bid phase, where there are no physical impacts. This document is primarily aimed at corporate officers, site managers and other relevant personnel responsible for the management, monitoring and conservation of biodiversity throughout the lifecycle of upstream oil and gas operations (see Figure 1). It is often difficult to definitively label environmental degradation as a result of either primary or secondary impacts. Most primary impacts can be relatively easily predicted with a standard Environmental and Social Impact Assessment (ESIA) process, based on the proposed activity and an understanding of the surrounding ecosystem. However, although secondary impacts may be predicted with a thorough ESIA process that includes biodiversity issues and explicitly links environmental and social issues, in some cases, the potential for such impacts may not be identified or realized until much later in the project cycle, or even after the project has been decommissioned. The potential range of biodiversity impacts that might be faced by a company are summarized in Box 1.