The justification, design and implementation of Ecological Risk Assessments of the effects of fishing on seabirds

Many marine species are threatened by high levels of incidental mortality in fisheries. This paper reviews the design of selected recent, detailed Ecological Risk Assessments (ERAs) of the effects of fishing on seabirds. Several aspects of ERA methodology for seabirds are still in development, including the most appropriate ways to: predict seabird distribution and fisheries overlap; handle data gaps; compare productivity and susceptibility among species; and incorporate data on bycatch. Nor is there consensus on rules for selecting species or populations for inclusion in assessments, the appropriate spatial and temporal resolution for the analyses, and the definition of risk. Despite these uncertainties, the clear benefits of undertaking quantitative or semi-quantitative ERAs include the identification of particularly vulnerable species or populations and of key areas and seasons in which bycatch may be occurring, and the highlighting of data gaps and priorities for future monitoring. ERAs are likely to be particularly effective where explicit links are established at the outset between the outcomes or conclusions of the ERA and management responses. A precautionary approach to bycatch mitigation can then be embedded in the broader fisheries management framework. However, this requires that the ERA process is not overly complex or is prolonged to the extent that it draws attention away from existing responsibilities and commitments to reduce bycatch per se. When selecting the best approach, it is vital to balance desired outputs against the availability of data for the assessment, and to deal with data gaps in a precautionary manner.