ICES WGMME REPORT 2012 ICES ADVISORY COMMITTEE ICES CM 2012/ACOM:27 Report of the Working Group on Marine Mammal Ecology (WGMME) 5–8 March 2012 Copenhagen, Denmark International Council for the Exploration of the Sea Conseil International pour l’Exploration de la Mer H. C. Andersens Boulevard 44–46 DK-1553 Copenhagen V Denmark Telephone (+45) 33 38 67 00 Telefax (+45) 33 93 42 15 www.ices.dk [email protected] Recommended format for purposes of citation: ICES. 2012. Report of the Working Group on Marine Mammal Ecology (WGMME), 5– 8 March 2012, Copenhagen, Denmark. ICES CM 2012/ACOM:27. 146 pp. For permission to reproduce material from this publication, please apply to the Gen- eral Secretary. The document is a report of an Expert Group under the auspices of the International Council for the Exploration of the Sea and does not necessarily represent the views of the Council. © 2012 International Council for the Exploration of the Sea ICES WGMME REPORT 2012 | i Contents Executive summary ................................................................................................................ 1 1 Introduction .................................................................................................................... 3 2 Adoption of the agenda ................................................................................................ 4 3 ToR a) Population structure ......................................................................................... 5 3.1 Management frameworks and management units .......................................... 5 3.1.1 Defining management units in practice ................................................ 7 3.2 Overarching WGMME recommendation on MUs ......................................... 20 3.3 New survey and abundance information ........................................................ 21 3.3.1 Abundance of harbour porpoises around the Dogger Bank (North Sea) .............................................................................................. 21 3.3.2 Abundance of harbour porpoises in the German North Sea and southwestern Baltic Sea ................................................................. 23 3.3.3 Abundance of harbour porpoises in Dutch waters ........................... 24 3.3.4 Harbour porpoise in the English Channel .......................................... 26 3.3.5 Abundance of common dolphins in Portuguese waters .................. 26 3.4 Interpreting numbers of stranding events ...................................................... 28 3.5 Large scale cetacean surveys in the European Atlantic ................................. 29 3.5.1 Abundance estimates from CODA and SCANS-II ............................ 29 3.5.2 Abundance estimates from T-NASS.................................................... 29 3.5.3 Future surveys ........................................................................................ 31 3.6 Population structure of harbour seals in the eastern North Atlantic .......... 31 3.7 North Atlantic right whale population structure ........................................... 32 3.8 References ............................................................................................................ 32 4 Tor b) Develop biodiversity indicators in support of policy drivers, and develop indicators that are robust to expected uncertainties in data and/or to provide a quantitative analysis of the potential effects of data limitations on indicator performance ......................................................... 35 4.1 Introduction ......................................................................................................... 35 4.2 Development of seal indicators through ICG-COBAM................................. 36 4.2.1 OSPAR’s seal EcoQOs ........................................................................... 37 4.2.2 Grey seal .................................................................................................. 41 4.3 Information needs identified by ICG COBAM for seal indicators ............... 43 4.3.1 Abundance, distribution and management units for harbour seals........................................................................................... 43 4.3.2 Monitoring and baselines for seal indicators ..................................... 50 4.4 Development of cetacean indicators ................................................................ 50 4.4.1 Monitoring cetaceans ............................................................................ 51 4.4.2 Compilation of existing data on abundance ...................................... 53 ii | ICES WGMME REPORT 2012 4.4.3 Development of a baseline for each species ....................................... 56 4.5 Bycatch indicators ............................................................................................... 57 4.5.1 Target (in %) for other species than the harbour porpoise ............... 57 4.5.2 Population (or management unit) against which to set the target (developed already for harbour porpoises in the North Sea), development of a baseline for each population or management unit and development of an assessment tool ........................................................................................................... 59 4.5.3 Development of a standardized monitoring methodology for bycatch or alternatively a mechanism for standardizing data post collection ................................................................................ 60 4.6 Potential indicators from strandings ................................................................ 61 4.6.1 Other potential indicators from strandings ........................................ 64 4.6.2 Synthetic compound contamination: PCBs ........................................ 66 4.6.3 Applicability of indicators from stranding schemes ......................... 67 4.6.4 Potential indicators from biopsy data taken from free ranging cetaceans ................................................................................... 67 4.7 References ............................................................................................................ 68 5 ToR c) Outline and review the effects of wave energy devices on marine mammals and provide recommendations on research needs, monitoring and mitigation schemes ........................................................................ 72 5.1 Introduction ......................................................................................................... 72 5.2 Features of wave energy converters relevant to marine mammals ............. 72 5.2.1 Surface attenuators ................................................................................ 73 5.2.2 Point absorbers ....................................................................................... 73 5.2.3 Oscillating wave surge converters ....................................................... 74 5.2.4 Oscillating water column devices ........................................................ 75 5.2.5 Overtopping devices ............................................................................. 75 5.2.6 Submerged pressure differential devices ........................................... 76 5.2.7 Other ........................................................................................................ 76 5.3 General WEC characteristics ............................................................................. 77 5.4 Summary of distribution and scale of some of the wave energy developments in ICES waters ........................................................................... 78 5.5 Potential effects of wave energy developments on marine mammals .............................................................................................................. 82 5.5.1 Installation .............................................................................................. 82 5.5.2 Operation ................................................................................................ 84 5.5.3 Decommissioning .................................................................................. 88 5.5.4 Synergistic effects ................................................................................... 89 5.6 Overview of international guidelines on monitoring .................................... 89 5.7 Key knowledge gaps .......................................................................................... 90 5.7.1 Baseline information .............................................................................. 90 5.7.2 Noise ........................................................................................................ 91 5.7.3 Electromagnetic (EM) fields ................................................................. 92 5.7.4 Cumulative effects ................................................................................. 93 ICES WGMME REPORT 2012 | iii 5.7.5 Management ........................................................................................... 93 5.7.6 Standardisation and data sharing ........................................................ 93 5.7.7 Animal-device interactions ................................................................... 94 5.8 Recommendations .............................................................................................. 94 5.8.1 Main recommendation: Management framework ............................ 94 5.8.2 Strategic spatial and temporal planning ............................................