Final Contract Report 1 April 2015 to 31 March 2018 for Marine Scotland, Scottish Government www.strandings.org Prepared by Andrew Brownlow, Nick Davison & Mariel ten Doeschate www.strandings.org 1 | P a g e Table of Contents Executive Summary .............................................................................................................. 1 Section 1: History of the project ...................................................................................... 2 Section 2: Project overview ............................................................................................. 2 2.1 Details of work ..................................................................................................3 Section 3: Volunteer network .......................................................................................... 5 3.1 Section 1: Summary of volunteer programme .................................................5 3.1.1 Engagement with volunteer network. ..................................................................... 5 3.1.2 Health and safety..................................................................................................... 6 3.1.3 Carcass collection ................................................................................................... 6 3.1.4 Future work ............................................................................................................. 7 Section 4: Marine species strandings around the Scottish coast (2015-2018) ........... 9 4.1 Strandings overview .........................................................................................9 4.2 Necropsies .......................................................................................................9 4.3 Selection of samples for necropsy ....................................................................9 4.4 Necropsy overview 2015 to 2018 ................................................................... 13 4.5 Cause of death categories.............................................................................. 13 4.5.1 Live stranding ....................................................................................................... 13 4.5.2 Bycatch ................................................................................................................. 13 4.5.3 Entanglement ........................................................................................................ 13 4.5.4 Bottlenose Dolphin (BND) attack ......................................................................... 14 4.5.5 Grey seal attack (cetaceans). Acute, primary trauma cases suspected to be seal predation on harbour porpoise............................................................................................ 14 4.5.6 Grey seal attack (cetaceans). Chronic, secondary infection possibly due to seal bite lesions on harbour porpoise......................................................................................... 14 4.5.7 Grey seal attack (pinnipeds), spiral or “corkscrew” seals. .................................... 14 4.5.8 Meningoencephalitis ............................................................................................. 15 4.5.9 Pneumonia............................................................................................................. 15 4.5.10 Generalised bacterial infection .......................................................................... 15 2 | P a g e 4.5.11 Starvation ........................................................................................................... 15 4.5.12 Not established .................................................................................................. 15 4.1 Necropsy protocol .......................................................................................... 15 Section 5: Cetacean species found stranded in Scotland ........................................... 17 5.1 Harbour porpoise (Phocoena phocoena) ....................................................... 17 5.2 Bottlenose dolphin (Tursiops truncatus) ......................................................... 22 5.3 Long-finned pilot whale (Globicephala melas) ................................................ 24 5.4 Sperm whale (Physeter macrocephalus) ........................................................ 28 5.5 Pelagic delphinids (excluding long-finned pilot whales) .................................. 31 5.5.1 Short-beaked common dolphin (Delphinus delphis) ............................................ 35 5.5.2 Striped dolphin (Stenella coeruleoalba) ................................................................ 39 5.5.3 White-beaked dolphin (Lagenorhynchus albirostris) ............................................ 42 5.5.4 Atlantic white-sided dolphin (Lagenorhynchus acutus) ....................................... 44 5.5.5 Risso’s dolphin (Grampus griseus) ....................................................................... 46 5.5.6 Killer whale (Orcinus orca) .................................................................................. 48 5.6 Beaked whales ............................................................................................... 51 5.6.1 Cuvier’s beaked whale (Ziphius cavirostris) ........................................................ 52 5.7 Sowerby’s beaked whale (Mesoplodon bidens) ............................................. 55 5.7.1 Northern bottlenose whale (Hyperoodon ampullatus) .......................................... 56 5.8 Mysticetes ...................................................................................................... 58 5.8.1 Minke whale (Balaenoptera acutorostrata) ........................................................... 60 5.8.2 Fin Whale (Balaenoptera physalus) ...................................................................... 62 5.8.3 Humpback whale (Megaptera novaeangliae)........................................................ 64 5.9 Kogia sp. ........................................................................................................ 65 Section 6: Mass stranding events (MSE’s) multiple strandings and unusual mortality events (UME’s) .................................................................................................................... 66 6.1 M161/15 – long-finned pilot whales (Globicephala melas) ............................. 67 6.1.1 Stranding overview ............................................................................................... 67 6.1.2 Summary ............................................................................................................... 70 6.2 M242 /15 – long-finned pilot whales (Globicephala melas) ............................ 70 3 | P a g e 6.3 M267/15 – short-beaked common dolphins (Delphinus delphis) .................... 71 6.4 M25/16 – Risso’s dolphin (Grampus griseus) ................................................. 72 6.5 M31/17 – short-beaked common dolphins (Delphinus delphis) ...................... 73 6.6 M350/17 – white beaked dolphin (Lagenorhynchus albirostris) ...................... 76 Section 7: Seal species found stranded in Scotland ................................................... 77 7.1 Harbour seal (Phoca vitulina) ......................................................................... 79 7.2 Grey seal (Halichoerus grypus) ...................................................................... 85 Section 8: Investigation into ‘corkscrew’ lesions ........................................................ 91 Section 9: Sharks and marine turtles ............................................................................ 92 9.1 Overview ........................................................................................................ 92 9.2 Sharks ............................................................................................................ 92 9.2.1 Basking shark (Cetorhinus maximus) ................................................................... 92 9.2.2 Blue shark (Prionace glauca) ................................................................................ 93 9.2.3 Porbeagle shark (Lamna nasus) ............................................................................ 95 9.3 Marine turtles .................................................................................................. 96 9.3.1 Loggerhead turtle (Caretta Caretta) ..................................................................... 96 9.4 Leatherback turtle (Dermochelys coriacea) .................................................... 98 Section 10: Knowledge exchange and outputs ............................................................ 101 10.1 Website and digital media ......................................................................... 101 Section 11: Staff ............................................................................................................. 103 Appendix 1: Outputs ......................................................................................................... 104 11.1 Publications ............................................................................................... 104 11.2 Publications (submitted or in press 2018) ................................................. 109 11.3 Conference presentations ......................................................................... 109 11.4 Poster Presentations ................................................................................. 112 Appendix 2: Conference attendance/Meetings