Background information on marine mammals relevant to Strategic Environmental Assessments 2 and 3 P.S. Hammond, J.C.D. Gordon, K. Grellier, A.J. Hall, S.P. Northridge, D. Thompson & J. Harwood Sea Mammal Research Unit, Gatty Marine Laboratory University of St Andrews, St Andrews, Fife KY16 8LB SEA3 - Marine Mammals CONTENTS NON-TECHNICAL SUMMARY...............................................................................................1 Distribution and abundance.....................................................................................................1 Ecological importance ............................................................................................................2 Sensitivity to disturbance, contamination and disease..............................................................3 Noise ..................................................................................................................................3 Contaminants......................................................................................................................4 Oil spills .............................................................................................................................4 Oil dispersants ....................................................................................................................4 Disease ...............................................................................................................................4 Bycatch and other non-oil related management issues.............................................................5 Bycatch...............................................................................................................................5 Ship collisions.....................................................................................................................5 Conservation frameworks .......................................................................................................5 Conclusions ............................................................................................................................6 1. DISTRIBUTION AND ABUNDANCE..............................................................................8 1.1 Introduction.....................................................................................................................8 1.2 Baleen Whales ................................................................................................................9 1.2.1 Minke whale Balaenoptera acutorostrata .................................................................9 1.3 Toothed whales.............................................................................................................10 1.3.1 Harbour porpoise Phocoena phocoena...................................................................10 1.3.2 Bottlenose dolphin Tursiops truncatus...................................................................11 1.3.3 White-beaked dolphin Lagenorhynchus albirostris.................................................11 1.3.4 Atlantic white-sided dolphin Lagenorhynchus acutus ............................................12 1.3.5 Killer whale Orcinus orca .....................................................................................12 1.3.6 Risso’s dolphin Grampus griseus ..........................................................................12 1.3.7 Short-beaked common dolphin Delphinus delphis .................................................12 1.3.8 Long-finned pilot whale Globicephala melas.........................................................13 1.3.9 Sperm whale Physeter macrocephalus ...................................................................13 1.4 Pinnipeds ......................................................................................................................13 1.4.1 Harbour (or common) seal, Phoca vitulina ............................................................13 1.4.2 Grey seal, Halichoerus grypus ...............................................................................14 2. ECOLOGICAL IMPORTANCE.......................................................................................16 2.1 Harbour seal..................................................................................................................16 2.1.1 Diet composition ...................................................................................................16 2.1.2 Prey consumption..................................................................................................16 2.1.3 Foraging movements and distribution....................................................................17 2.2 Grey seal.......................................................................................................................17 2.2.1 Diet composition ...................................................................................................17 2.2.2 Prey consumption..................................................................................................18 2.2.3 Foraging movements and distribution....................................................................18 2.3 Cetaceans......................................................................................................................19 2.3.1 Harbour porpoise...................................................................................................19 2.3.2 Minke whale..........................................................................................................19 2.3.3 White-beaked dolphin............................................................................................20 2.3.4 Atlantic white-sided dolphin..................................................................................20 2.3.5 Killer whale...........................................................................................................20 2.3.6 Bottlenose dolphin.................................................................................................20 2.3.7 Other species.........................................................................................................20 Report No. TR_006_Rev1 1 August 2002 SEA3 - Marine Mammals 3. SENSITIVITY TO DISTURBANCE, CONTAMINATION AND DISEASE ...................22 3.1 Noise.............................................................................................................................22 3.1.1 Effects of man-made sounds on marine mammals..................................................22 3.1.2 Responses of marine mammals to different types of noise .....................................29 3.1.3 Research Requirements .........................................................................................33 3.2 Contaminants ................................................................................................................34 3.2.1 Background...........................................................................................................34 3.2.2 Sources of Data .....................................................................................................36 3.2.3 Knowledge ............................................................................................................36 3.2.4 Gaps in knowledge ................................................................................................39 3.3 Disease..........................................................................................................................39 3.3.1 Background...........................................................................................................39 3.3.2 Sources of data......................................................................................................40 3.3.3 Knowledge ............................................................................................................40 3.3.4 Gaps in Knowledge ...............................................................................................41 4. BYCATCH AND OTHER NON-OIL MANAGEMENT ISSUES ....................................44 4.1 Bycatch.........................................................................................................................44 4.2 Other issues...................................................................................................................45 5. CONSERVATION FRAMEWORKS ...............................................................................46 5.1 Cetaceans......................................................................................................................46 5.1.1 Europe...................................................................................................................46 5.1.2 UK ........................................................................................................................46 5.2 Seals .............................................................................................................................47 5.2.1 Europe...................................................................................................................47 5.2.2 UK ........................................................................................................................47 6. CONCLUSIONS ..............................................................................................................48 REFERENCES.........................................................................................................................50