Operationalising Bow-tie analysis to assess main concerns about biodiversity change in European Seas

Marine biodiversity is adversely affected by many human activities and their pressures. As such, there is the need for a cause-consequence-response method to objectively address the risks associated with those adverse changes. Such a method is the ISO-accredited Bow-tie technique as an objective and structured approach giving the causes, preventative control measures, mitigation and compensation measures and consequences of changes to biodiversity. Here, the Bow-tie method underpinned by the cause-consequence-response DAPSI(W)R(M) framework was used and adapted to help managers map out risks to biodiversity requiring management of the human activities and their relevant pressures, in specific case study areas (termed Broad Belt Transects, BBTs). Instead of using restrictive proprietary software, a more-flexible template framework was developed in Microsoft PowerPoint to allow a broad user base. This employed standardised lists of elements (and further adapted during the application process) allowing the development of unique, but standardised and directly comparable Bow-ties for all BBTs. The methods of developing the template and standardised lists are described together with the techniques used to help quantify this usually qualitative approach. The successful application of the Bow-tie method in case studies from the European seas shows the adaptability of this approach in ways wider than the original policy-driven risk-assessment use. Although designed for European seas, the approach and standardised lists are sufficiently generic for adoption in wider areas worldwide.