Evaluating Ireland's IBIA as an approach to improving the quality and effectiveness of biodiversity impact assessment

•Current practice was shown to involve fragmented consideration of biodiversity.•This led to the development of IBIA (Integrated Biodiversity Impact Assessment).•IBIA systematically coordinates biodiversity assessments of several EU Directives.•IBIA satisfies legal requirements under the Habitats, SEA and EIA Directives.•IBIA links assessment requirements, dovetails scoping stages, and minimises effort.

The assessment of potential impacts of plans, programmes and projects on biodiversity is required under various legislative remits (including the European Union's Habitats, Strategic Environmental Assessment and Environmental Impact Assessment Directives). The objective of such assessments is to ensure that potential negative impacts on both protected nature conservation sites and species and wider biodiversity are efficiently identified in a timely manner, quantified and subsequently avoided or mitigated, while enhancing positive effects. The procedural requirements of these legal obligations vary and, as a result, differing methodological steps, data gathering and analysis methods, and impact assessment techniques are commonly applied under each individual process, often leading to uncoordinated assessment efforts and results (in terms, for example, of scope, scale and assessment detail).In order to address these issues and improve current practice, an Integrated Biodiversity Impact Assessment (IBIA) methodology has been developed in Ireland with the overall aim of providing a holistic and systematic approach to biodiversity impact assessment. The IBIA framework seeks to ensure that relevant procedures are effectively integrated, time and resource efficiencies are optimised, and unnecessary duplication avoided. Particular emphasis is given to compliance with legal requirements, integration and communication of scientific knowledge, spatial assessment and biodiversity data considerations, and integration of biodiversity aspects with a variety of other concerns during the plan-making process. This paper presents the IBIA methodology and critically examines current key issues in biodiversity impact assessment that can be potentially addressed through IBIA, as well as remaining challenges. In addition, and in order to support the examination of the anticipated benefits of using this new methodological framework (such as biodiversity-inclusive planning through improved communication and coordinated assessment), two contrasting case studies are used, one pre-dating the development of IBIA and a second where elements of IBIA have been implemented.