Report of the Joint OSPAR/HELCOM/ICES Working Group on Marine Birds (JWGBIRD)

Hosted by the Flanders Marine Institute, the Joint ICES/OSPAR/HELCOM Working Group on Seabirds met in Ostende, Belgium, 1–5 October 2018. The meeting was co-chaired by Morten Frederiksen, Ian Mitchell and Volker Dierschke, and was attended by 15 members representing 11 countries. Following the tradition of the preceding meetings, the objectives of the meeting were to develop and implement indicators for seabirds under the Marine Strategy Framework Directive (MSFD), as well as to review and discuss seabird-related issues relevant for human uses of the sea. The meeting con-sisted of a series of interconnected workshops, where subgroups with floating mem-bership discussed Terms of Reference. Report chapters were drafted by Term of Reference leads and collated by the chairs.Further refinements of the existing indictor for breeding productivity in OSPAR were discussed. The suggested approach uses matrix population models to assess the impact of the observed level of breeding productivity on population growth rate, and relates the projected growth rate to IUCN criteria for species red-listing.Links between trends in population abundance (HELCOM) and potential drivers were explored. Preliminary results are complex and require further interpretation.A combined mid-winter aerial survey of the offshore Baltic was carried out in early 2016. The data have been collated, but results are not ready yet.The group discussed integration rules for GES assessments of birds under MSFD, both within and across species. ICES workshops in 2018 resulted in advice on these rules. JWGBIRD mostly agree with this advice, but propose a few changes.JWGBIRD reviewed the UK national assessment of seabirds under MSFD, and made suggestions for further development of indicators.A reporting template for the periodic assessments of OSPAR Threatened and/or De-clining Species and Habitats was tested for the black-legged kittiwake.The group reviewed the progress so far on assessing bycatch mortality of marine birds in the NE Atlantic. The main limitation currently is the near absence of regular moni-toring data on bycatch of birds. This also hampers the definition of threshold values for the MSFD indicator D1C1. The information collated by JWGBIRD will be used to inform a joint OSPAR-HELCOM workshop to examine possibilities for developing in-dicators for incidental by-catch of birds and marine mammals, planned for September 2019.JWGBIRD provided input to the HELCOM indicator review process as well as to the HELCOM workshop on migratory waterbirds in November 2018.