Jump to Main Content
Do biodiversity offsets achieve No Net Loss? An evaluation of offsets in a French department
- Bezombes, Lucie, Kerbiriou, Christian, Spiegelberger, Thomas
- Biological conservation 2019 v.231 pp. 24-29
- biodiversity, development projects, habitats, issues and policy, monitoring, protected species, surveys, wetlands, France
- Biodiversity offsetting is a policy approach that compensates for the ecological losses from development projects affecting biodiversity with equivalent gains through offsets, aiming at “No Net Loss” (NNL). Although offsets seem appealing in theory, several concerns have been raised about the difficulties reaching NNL in practice. While most of the discussion about offsets improvement is based on principles and strategies, we evaluated empirical evidence of offsets implemented, both from the procedure files (protected species and wetlands) and field surveys. Our objective was to evaluate whether offsets achieve NNL based on 91 procedure files in the Isère department in France. We identified that necessary data for assessing offsets gains, such as the location and offset sites' initial state, were not available in part (location) or all (initial state) procedure files investigated. We evaluated 59 offsets implemented for 22 development projects and where minimum data for monitoring offsets were available; we surveyed the presence or absence of target species and habitat from the offset site. The type of offsets (restoration, creation or maintenance of target habitat) was one of the characteristics that helped to explain both species and habitat absence, implying offset failure. Based on our analysis, we suggest three principal angles for progressing in NNL achievement: (i) collecting and publishing a set of essential information on offsets, (ii) requiring a management plan for each offset, and (iii) accumulating empirical evidence of offsets failure and success.