Ecological mitigation measures in English Environmental Impact Assessment

Abstract Built development is one of the main drivers of biodiversity loss in the UK. Major built developments usually require an Environmental Impact Assessment (EIA) to be conducted, which frequently includes an Ecological Impact Assessment (EcIA) chapter. By identifying the flaws in EcIA mitigation measure proposals and their implementation in completed developments, it may be possible to develop measures to reduce biodiversity loss and help meet the UK's EU obligation to halt biodiversity loss by 2020. A review of 112 English EcIAs from 2000 onwards was conducted to provide a broad-scale overview of the information provision and detail of ecological mitigation measures. Audits of seven EIA development case study sites provided finer-scale detail of mitigation measure implementation, and the effectiveness of their grassland and marginal habitat creation and management measures was assessed using standard NVC methodology. Despite higher than expected levels of mitigation measure implementation in completed developments, EcIA mitigation proposal information and detail has seen little improvement since a 1997 review, and the effectiveness of the habitat mitigation measures studied was poor. This suggests that measures to improve ecological mitigation measures are best targeted at ecological consultants. A recommendation for EcIA-specific training of Competent Authorities is also made.