Working Group on Marine Mammal Ecology (WGMME)

Abstract

The Working Group on Marine Mammal Ecology (WGMME), chaired by Anita Gilles (Germany) and Anders Galatius (Denmark), met at the Institute for Terrestrial and Aquatic Wildlife Re-search, University of Veterinary Medicine Hannover, Foundation, in Büsum, Germany, during 11–14 February 2019. On behalf of the working group, the chairs would like to thank the Institute for Terrestrial and Aquatic Wildlife Research (ITAW) for hosting the meeting. A total of 17 participants from eight countries attended the meeting on site. The list of partici-pants, including those contributing remotely, and contact details are given in Annex 1. The Chairs acknowledge the diligence and hard work of all the participants before, during and after the meeting, which ensured that the Terms of Reference could all be addressed. The Working Group gratefully acknowledges the support given by several additional experts that kindly pro-vided information and/or reports for use by WGMME and evaluated the threats matrices and related text (see Annex 1). Two terms of references were standing ToRs; under the first of these, ToR A, new and updated information on seal and cetacean population abundance, population/stock structure, manage-ment frameworks, and anthropogenic threats to individual health and population status were reviewed. Usually data on marine mammal surveys are only conducted during one season, but new data from Ireland revealed profound differences between summer and winter abundance and distribution of cetaceans, with implications for the spatial management of these species. New habitat modelling for cetacean species in the Northwest European Seas and North Atlantic Ocean and Mediterranean based on collated survey data as well as findings on threats to marine mammals such as bycatch, pollution, marine debris and noise were summarised under this ToR. Under ToR B, WGMME reviewed information on the ecological roles of marine mammals, ex-panding on efforts to review impacts on fisheries, interspecific competition, diet and impact on fish stocks from previous reports. The complexity and multitude of ecological interactions is un-derlined. A special emphasis under this ToR was put on the role of marine mammals as hosts and vectors of parasites.

ToR C was implemented to review aspects of marine mammal fishery interactions not covered by ICES WGBYC. In 2019, WGMME focused its efforts on i) reviewing seal interactions with fisheries, including the numbers of bycaught seals, ii) investigating additional data sources for cetacean bycatch such as strandings, voluntary recording schemes and interview surveys, iii) identifying of potential bycatch risk areas, and iv) a review of recent work on setting safe limit thresholds for bycatch of marine mammals. To implement bycatch data in the management of marine mammals it is stressed that they should be aggregated on a management unit basis and corresponding data on abundance should be available. Under ToR D, WGMME followed up and updated on the 2015 threat matrix for the main marine mammal species in each of the regional sea areas. In addition to this update, a review of cumu-lative impacts from multiple environmental pressures and recent efforts to meaningfully analyse such cumulative impacts was produced. The approaches used to assess cumulative impacts are usually limited to a particular pressure. Efforts to expand the scopes of these tools are impeded by the complexity of the relevant interactions and knowledge gaps. ToR E, updating the database for seals, is the second standing term of reference. This year, WGMME adapted the ICES WGMME seal database to a proper database format and updated the data. WGMME also repeated its support for a data call from OSPAR to provide data for assessments under OSPAR indicators M3 and M5 on seal abundance and distribution

The WGMME updated ToRs for 2020 (see Annex 2) and discussed meeting venues. The Institute of Marine Sciences (ICM-CSIC) offered to host the 2020 meeting in Barcelona (Spain) alongside the meeting of ICES WGBIODIV in order to arrange common sessions and establish cooperation between the two groups (see proposed ToR B for 2020)