Consultancy Report Client: Department for Environment, Food and Rural Affairs (DEFRA) TRENDS IN CETACEAN STRANDINGS AROUND THE UK COASTLINE, CETACEAN AND MARINE TURTLE POST-MORTEM INVESTIGATIONS 2004 (CONTRACT CRO 238) Authors: R. C. Sabin, P. D. J. Chimonides, C. J. H. Spurrier (NHM) P. D. Jepson, R. Deaville (ZSL) R. J. Reid, I. A .P. Patterson (SAC) R. Penrose (MEM) R. Law (CEFAS) November 2005 Report No. ECM 516G/05 NHM Consulting Environment: Coastal & Marine Sector Tel: +44 (0) 207 942 5636 The Natural History Museum, Cromwell Rd, London SW7 5BD, U.K.
Transcript
Consultancy Report Client: Department for Environment, Food and Rural Affairs (DEFRA)
TRENDS IN CETACEAN STRANDINGS AROUND THE UK COASTLINE, CETACEAN AND MARINE TURTLE
Authors: R. C. Sabin, P. D. J. Chimonides, C. J. H. Spurrier (NHM) P. D. Jepson, R. Deaville (ZSL) R. J. Reid, I. A .P. Patterson (SAC) R. Penrose (MEM) R. Law (CEFAS) November 2005 Report No. ECM 516G/05
Tel: +44 (0) 207 942 5636 The Natural History Museum, Cromwell Rd, London SW7 5BD, U.K.
CONTENTS General introduction to the joint report 3 Abstract 4 Part A: Trends in cetacean strandings around the UK coastline for the year 2004 6 Introduction 6 Results 8 Distribution of cetacean species 11 Balaenoptera acutorostrata – minke whale 11 Balaenoptera physalus – fin whale 11 Balaenoptera species indeterminate 13 Megaptera novaeangliae – humpback whale 13 Delphinus delphis – short-beaked common dolphin 13 Delphinus delphis/Stenella coeruleoalba - common/striped dolphin species indeterminate 16 Globicephala melas – long-finned pilot whale 16 Grampus griseus – Risso’s dolphin 16 Lagenorhynchus acutus – white-sided dolphin 17 Lagenorhynchus albirostris – white beaked dolphin 17 Lagenorhynchus species indeterminate 17 Stenella coeruleoalba – striped dolphin 18 Tursiops truncatus – bottlenose dolphin 18 Unidentified dolphins 19 Phocoena phocoena – harbour porpoise 19 Physeter catodon – sperm whale 22 Hyperoodon ampullatus – northern bottlenose whale 23 Mesoplodon bidens – Sowerby’s beaked whale 24 Ziphius cavirostris – Cuvier’s beaked whale 24 Unidentified odontocetes and other cetaceans 24 Part B: UK cetacean and marine turtle post-mortem investigations for the year 2004 25 Introduction 25 Results 27 Causes of death 27 Entanglement in fishing gear (bycatch) 27 Physical trauma 27 Infectious disease mortality 28 Starvation 28 Live-stranding 29 Gas embolism 29 Tumours 29 Other causes of death 29 Investigations of relationships between environmental contaminants and health status 32
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Toxicology data from UK stranded harbour porpoises 32 Additional collaborative research activity 32 Scientific meetings attended 34 Additional report writing 34 Student theses 34 Publications for the year 2004 35 References 36 Appendices 38 Appendix 1: Distribution maps – UK cetacean strandings, 2004 38 Appendix 2: Lengths of stranded cetacean by species, 2004 50 Appendix 3: Stranded cetacean species by region, 2000-2004 53
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GENERAL INTRODUCTION TO THE JOINT REPORT This report is based on research conducted under contract to the Department for Environment, Food and Rural Affairs (Defra) between 1st January and 31st December 2004. The following organisations were contracted or subcontracted under these agreements: Organisation Contract no. The Natural History Museum (NHM) CRO238 Cromwell Road South Kensington London SW7 5BD Tel: 020 7942 5155 Fax: 020 7942 5572 Subcontract no. Zoological Society of London (ZSL) ZRT C S047 516 COa Regent’s Park London NW1 4RY Tel: 020 7449 6691 Fax: 020 7586 1457 Wildlife Unit ZRT C S047 516 COb SAC Veterinary Science Division (Inverness) Drummondhill Stratherrick Road Inverness IV2 4JZ Tel: 01463 243030 Fax: 01463 711103 The authors involved in the production of this report are as follows: R. C. Sabin, P. D. J. Chimonides and C. J. H. Spurrier (NHM) P. D. Jepson and R. Deaville (ZSL) R. J. Reid and I. A. P. Patterson (SAC) R. Penrose: Marine Environmental Monitoring (MEM) R. Law: Centre for Environment, Fisheries and Aquaculture Science (CEFAS)
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ABSTRACT In 2004, 799 UK-stranded cetaceans were reported which is the highest number ever recorded within the UK since records began in 1913. The last five years (1999-2004) have seen progressively increasing numbers of UK-stranded cetaceans, predominantly due to increasing winter strandings of short-beaked common dolphins (Delphinus delphis) and harbour porpoises (Phocoena phocoena) in south-west England. Cetacean strandings rates in other UK regions have remained more stable. Although post-mortem examinations have shown that the increasing numbers of common dolphin and harbour porpoise strandings in SW England in recent years are mainly cetaceans incidentally caught in commercial fishing nets (bycatch), other factors such as changes in abundance and distribution of these species and increased reporting effort in south west England may also have a role in this phenomenon. There were no unusual mass mortality events or cases of morbillivirus infection in cetaceans or marine turtles during 2004. The most common UK-stranded cetacean species in 2004 was the harbour porpoise of which 472 were recorded. The most common causes of mortality of the 166 UK-stranded harbour porpoises examined at post-mortem in 2004 were entanglement in fishing gear (bycatch) (n=37), attack from bottlenose dolphins (Tursiops truncatus) (n=37), pneumonias due to combinations of parasitic, bacterial and fungal infections (n=28), and starvation (n=17). An additional nine bycaught harbour porpoises were retrieved directly from fishing vessels for post-mortem examination. All cases of fatal attack from bottlenose dolphins occurred in Northeast Scotland and West Wales where porpoises share sympatric distributions with resident bottlenose dolphin populations. The annual number of harbour porpoises killed by bottlenose dolphins has increased significantly in West Wales between 1999 and 2004. As in previous years, bycatch was the most common cause of death in UK-stranded short-beaked common dolphins accounting for 32 of the 46 (70%) examined in 2004. The majority of both short-beaked common dolphin and harbour porpoise bycatches typically stranded in southwest England (Cornwall and Devon) between January and April. Investigations of potential relationships between exposure to persistent environmental pollutants and health status in UK harbour porpoises continued in 2004 in collaboration with the Sea Mammal Research Unit (University of St Andrews) and the CEFAS Burnham Laboratory, Essex. The first case-control studies demonstrated significant associations between elevated blubber polychlorinated biphenyls (PCBs) levels and infectious disease mortality (compared to controls that died of acute physical trauma) and this association was not confounded by a range of factors including age, sex, stranding location and two quantitative indices of nutritional status. The second study took these analyses one step further and conducted a slightly different analysis to calculate the odds ratio for increased risk of infectious disease mortality from increasing levels of polychlorinated biphenyls (PCBs) in blubber. These novel analyses could form the basis of future risk assessment-type analyses to predict the population level impacts of immunosuppressive pollutants in populations of known size and PCB exposure. Since the publication in 2003 of the first pathological evidence of acute and chronic gas and fat embolism in cetaceans from the UK and the Canary Islands (in
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collaboration with the Department of Veterinary Pathology of the University of Las Palmas, Gran Canaria), four new cases of cetacean gas embolism were diagnosed in 2004 in two common dolphins (one bycaught/found at sea, the other stranded in South-west England), a Sowerby’s beaked whale (Mesoplodon bidens) stranded in Wales and a harbour porpoise that stranded in Scotland.
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Part A
TRENDS IN CETACEAN STRANDINGS AROUND THE COASTLINE OF THE UNITED KINGDOM FOR 2004
Introduction The Natural History Museum (NHM) has been recording and investigating incidents of cetacean strandings from around the coasts of the United Kingdom for more than 100 years. The work was formalised in 1913 when an agreement was created about the scientific study of cetacean strandings, between the Board of Trade and the NHM (at that time called the British Museum (Natural History)) and was endorsed by the Crown. This agreement created the rights of the NHM to the legal acquisition of Royal Fishes, i.e. the Crown allowed the Museum first refusal of all Royal Fish for the purposes of furthering their scientific study. When debated in Parliament in 1970 it was decided to retain the classifications of 'Fishes Royal' for the benefit of Science. Since 1990, the work has been funded by the Department of Environment (DoE, later DETR), now the Department for Environment, Food and Rural Affairs (Defra). Under the terms of the current contract with Defra, the NHM co-ordinates and investigates cetacean strandings in the United Kingdom as part of a partnership with the Zoological Society of London (ZSL), and the Scottish Agricultural College Veterinary Science Division (SAC), Inverness. All strandings information recorded by the NHM since 1913 has been entered onto the National Cetacean Strandings database at the Museum, allowing the rapid extraction, detailed analysis and interpretation of the data. The NHM continues to submit data from the UK Cetacean Strandings Project to the UK annual national report for ASCOBANS (Agreement on the Conservation of Small Cetaceans Of the Baltic And North Seas). Fourteen members of staff from the NHM were responsible for retrieving the carcasses of 28 cetaceans from locations around England for post-mortem analysis in 2004. Since 1995, numbers of reported cetacean strandings have continued to rise, due in part to increased recording effort and publicity for the UK Cetacean Strandings Project. The year 2004 saw the highest number of stranded cetaceans reported around the United Kingdom since records began in 1913. From 1st January to 31st December 2004, 799 reports were received, exceeding the previous highest annual total (774 for 2003) by 25. The main area of increase was the number of harbour porpoises reported – 472 in 2004 compared with 321 in 2003. Numbers of reported short-beaked common dolphins and unidentified dolphins (too decomposed to identify to species) were notably lower than those of 2003 (see Table 3).
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For the purposes of this report, the term ‘stranding’ is used to describe cetaceans washed ashore dead or alive, seen floating dead at sea or accidental capture in fishing gear (bycatch). Although records of live sightings are kept, they are not included in the analyses for this report, and are passed on to those organisations that analyse such records. The success of the UK Cetacean Strandings Project relies heavily upon the efforts of the countless numbers of individuals and organisations that make regular reports to the NHM. The NHM continues to be greatly helped in its work by H. M. Coastguard, the Cornwall Wildlife Trust (for strandings in Cornwall), Brixham Seawatch, Devon Wildlife Trust and the National Marine Aquarium (for strandings in Devon), Durlston Marine Project and Hampshire Wildlife Trust (for strandings in Dorset and Hampshire), Marine Environmental Monitoring (for strandings in Wales), H. M. Coastguard and the Ulster Museum (for strandings in Northern Ireland) and the Environment Department, States of Jersey. Data from Jersey are discussed separately and have not been included in the UK totals shown in this report (see page 10 and Appendices 3.4 & 3.5). The location of Jersey provides an important insight into cetacean strandings along the southwestern margin of the English Channel. The NHM’s ‘UK Cetacean Strandings’ website can be viewed at the following address:
http://www.nhm.ac.uk/research-curation/projects/strandings/ The standardised strandings reporting form NHM 136 can also be downloaded from the Museum’s website: http://www.nhm.ac.uk/research-curation/projects/strandings/procedures.html
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Results - 2004 In 2004, a total of 799 reports were received by the NHM from around the United Kingdom relating to strandings of dead cetaceans, strandings of live cetaceans, reports of carcasses seen floating dead at sea and observed cetacean bycatch* (see Table 1, Map 1 and Map 9*). Of the 34 reported live strandings, 3 were successfully returned to sea. There were 9 observed cases of cetacean bycatch in Sept/Oct 2004 (see Part B, page 27 and Map 9). Table 1: Report categories
Stranded, dead cetaceans 728Live-strandings 34Observed cetacean bycatch* 9Carcasses seen floating at sea 28
Total 799
Records for the year 2004 include details of at least 15 cetacean species: Table 2: Reported cetacean strandings etc. in the UK for 2004 by region and species
**Note: strandings data only are represented here. Live-sightings data comprising three records have been removed from the retrospective data analyses: SW.2000/76 unidentified dolphin, SW.2003/98b humpback whale Megaptera novaeangliae and SW.2003/311 minke whale Balaenoptera acutorostrata).
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Figure A2. Reported cetacean strandings etc. for England, Wales, Northern Ireland and the Isle of Man, compared with Scotland, 1998 – 2004
235 249280
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Figure A2, shows the reported number of cetacean strandings for England, Wales, Northern Ireland and the Isle of Man compared with those for Scotland. The number of reports for Scotland has remained fairly consistent over the past seven years, with little variation in the number of species recorded – 14 in 2004 compared with 13 in 2003 (see also Appendix 3.2). The most commonly reported cetacean in Scotland in 2004 was the harbour porpoise, with 83 records received (see Table 2). In Northern Ireland, 9 cetaceans were reported, which is comparable with recent years (Table 2 and Appendix 3.3). However, the range of species recorded is much wider – 5 in 2004, including rare records of humpback whale and Sowerby’s beaked whale. There is little difference between the total number of reports for England and Wales – 627 in 2004 compared with 620 in 2003 (Appendix 3.1). However, significant changes in species representation have taken place, most importantly the number of harbour porpoises stranded, which rose from 244 in 2003 to 384 in 2004. Numbers of short-beaked common dolphins and unidentified dolphins reported in 2004 are notably lower than 2003 (Appendix 3.1). Since 2003, the Environment Department, States of Jersey, have sent reports of cetacean strandings directly to the NHM. In 2004, 8 records were received comprising a minimum of 4 species (see Appendices 3.4 & 3.5), compared with 7 records in 2003. The three most commonly reported species were the short-beaked common dolphin, the harbour porpoise and the bottlenose dolphin. As with the UK mainland, strandings of short-beaked common dolphins occur mainly in February and March (Appendix 3.5). Since 2000, 4 of the 5 bottlenose dolphins reported have stranded in January, whilst harbour porpoise have been reported in February, April and November.
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Distribution of cetacean species - 2004
Balaenopteridae Minke whale or lesser rorqual (Balaenoptera acutorostrata) Fourteen stranded minke whales were reported around the UK in 2004, a figure consistent with previous years (see Map 2 and Tables 2 & 3). Twelve of these animals were reported stranded around the northern and western coasts of Scotland, primarily in June and July 2004 (n = 7; see Appendix 2.1). A single stranding was recorded at Kearney Point, Ards Peninsula, County Down, Northern Ireland on 10th June 2004 (SW.2004/182a). On 21st February 2004, a very decomposed baleen whale carcass washed ashore at Eccles on Sea, Norfolk. The carcass was 4.57 metres long, and identified provisionally as c.f. minke whale (SW.2004/89). It is likely that the carcass had floated some considerable distance before beaching. Sightings of minke whales are rare in the North Sea to the south of the Yorkshire coast (Reid et al, 2003; p. 16). The dates of stranding illustrated by the data broadly support field observations reported in the literature. Most sightings are made from May to September, with few records between October and April (Reid et al, 2003; p. 17). However, five of the minke whales recorded by the NHM in 2004 were reported in January/February and October/November. Growth parameters established for North Atlantic populations of minke whales give the mean length at sexual maturity for males at 6.75 metres and females at 7.2 metres (Christensen, 1980). Using these parameters, the data in Appendix 2 (Table 2.1) suggest that nine of the minke whales reported in 2004 may not have reached sexual maturity. Fin whale (Balaenoptera physalus) Seven fin whale strandings were reported to the NHM in 2004, the highest annual total since records began in 1913 (Map 3; Appendices 2.2 & 2.2.1). Records were received each month from July to October, with three of the strandings occurring in October. The temporal distribution of these strandings is consistent with sightings of fin whales made around the British Isles, which occur mainly between June and December (Evans, 1992). On 19th July 2004, a male fin whale measuring 16.50 metres in length was struck by a container ship whilst swimming in Liverpool Bay (SW.2004/228). The collision caused the death of the animal, which became lodged on the bulbous-bow of the container ship. The carcass was brought into port by the ship where post mortem examination was carried out. On 1st August 2004, a fin whale measuring 15.67 metres in length was found floating off Gilkicker Point, near Gosport, Hampshire (SW.2004/240; Plate 1). The carcass was bloated and some discolouration of the tissues was apparent, suggesting that the animal had been dead for several days. It is probable that the carcass had
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floated for a considerable distance before being spotted by a Hampshire Search and Rescue helicopter. As the carcass posed a hazard to shipping, it was towed into Lee-on-Solent, where the Harbourmaster gave permission for it to be landed for examination and eventual disposal.
Plate 1. Fin whale – (SW.2004/240), photographed floating off Gilkicker Point, Hampshire, 01 August 2004. Photograph: Mike Rowsell, Hampshire SAR Flight. On 23rd September 2004, a female fin whale measuring 18.45 metres in length washed ashore at St. Brides, Wentlooge, Newport on the Welsh coast (SW.2004/286; Plate 2). The carcass was in good condition and was extensively examined, photographed and sampled by Rod Penrose, Marine Environmental Monitoring. Post mortem examination was not carried out, although blubber thickness measurements suggested that nutritional stress might have contributed towards the death of the animal.
Plate 2. Fin whale – (SW.2004/286), stranded at St. Brides, Wentlooge, Newport, Wales on 23 September 2004. Photograph: Rod Penrose, Marine Environmental Monitoring. On 28th October 2004, the carcass of a badly decomposed fin whale measuring 16 metres in length was seen floating near Sharkham Point, Brixham, South Devon (SW.2004/328a; Plate 3). Species identification was confirmed using baleen plates, in combination with the shape of the skull and length of the throat grooves on the ventral surface of the carcass. The condition of the carcass suggested that the animal had been dead for a number of weeks.
Plate 3. Fin whale – (SW.2004/328a), beached at St. Mary’s Bay, Brixham, South Devon on 28 October 2004. Photograph: Gavin Black, Devon Wildlife Trust.
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Unidentified rorqual (Balaenoptera sp.) On 16th December 2004, the carcass of a large whale approximately 11 metres in length and in an advanced state of decomposition was found washed ashore to the west of Steephill Cove, Ventnor, Isle of Wight (SW.2004/357; Tables 2 & 3). Photographs were able to show the presence of throat grooves on the ventral surface of the carcass, and other external features confirmed identification to genus as Balaenoptera sp. The skull was missing, preventing identification to species level. The presence of an extruded penis confirmed the sex as male. Humpback whale (Megaptera novaeangliae) Two humpback whale strandings were reported to the NHM in 2004 (Map 3). The first, a decomposing carcass washed ashore at Aikerness, Evie, Orkney Islands, was found on 27th February (SW.2004/91d). The second carcass was found on an inaccessible stretch of coastline at Giant’s Causeway, County Antrim, Northern Ireland on 13th September (SW.2004/274b). The carcass of this animal was intact though moderately decomposed. No further details exist for either carcass. The points of strandings of both carcasses are consistent with distribution data based upon sightings, i.e. northern Irish Sea and Northern Isles of Scotland (Reid et al, 2003; p. 15).
Delphinidae
Short-beaked common dolphin (Delphinus delphis) In 2004, 159 short-beaked common dolphin strandings were reported to the NHM (Table 3 and Map 4). This represents a reduction of approximately 24% compared with 2003 (n = 209) but is still the second-highest annual total for this species since NHM records began in 1913. Figure A3, shows the breakdown of numbers by month and region for 2004; the majority of short-beaked common dolphins reported in 2004 were found stranded around the south west of England (Cornwall including the Isles of Scilly (n = 78), Devon (n = 53) and Dorset (n = 10), total n = 141), continuing the distribution trend seen in previous years. Data from recent years also show that from December, the number of reported short-beaked common dolphins begins to increase. Numbers usually peak from January to March, reducing gradually into April. However, Figure A3 shows a reduction in the number of reports for January 2004 (n = 19) compared with 2003 (n = 79) with a peak in March. Cumulative data for 1998 to 2004 (Figure A4) also show March as the peak month for strandings of this species. Outside Cornwall, Devon and Dorset, the only other English counties where strandings of short-beaked common dolphins were recorded in 2004 were Essex (January, n = 1), Merseyside (June, n = 1), Kent (June, n = 1, see Plate 4) and Lincolnshire (July, n = 1). Two carcasses were also found, floating in the English Channel at positions 49°56.6'N 04°05.2'W and 50°02.075'N 04°14.053'W, by the Greenpeace vessel Esperanza on 15th February 2004.
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As with previous years, data collected in 2004 indicate bycatch-related strandings of short-beaked common dolphins do not appear to be an issue in Welsh and Scottish waters, where 9 and 3 animals were recorded respectively.
Figure A3. Strandings etc. of short-beaked common dolphin by month for 2004
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Figure A4. Cumulative monthly totals of short-beaked common dolphins stranded, 1998-2004
he data collected in 2004 add to earlier strandings reports and broadly reflect other bservational data, suggesting that the critical period for bycatch-related-common olphin strandings is from November/December to March/April each year. The
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cumulative monthly data in Figure A4 show the peak period for strandings as January to March.
Plate 4. Male short-beaked common dolphin – (SW.2004/183), 2.29 metres long, stranded at Milton Ranges, near Gravesend, Kent on 11 June 2004. Cause of death determined as live stranding. Photograph: Emma Thompson, Environment Agency. Figure A5, shows length data for short-beaked common dolphins recorded during the period 2000-2004. Based upon length, the data show an increase across the age spectrum including young/immature animals stranded in the period January to March. Birth length is given as 80 to 90 centimetres by most authors (Evans, 1994; p.204). Geographical variation in maximum length of fully mature adults has been noted for this species (Evans, 1994), but the range given for the eastern North Atlantic is 1.6 to 2.6 metres (Evans, 1995).
Figure A5. Short-beaked common dolphin, length by month 2000-2004
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Short-beaked common dolphin / striped dolphin indeterminate (Delphinus delphis / Stenella coeruleoalba) In 2004, 8 strandings were recorded as short-beaked common/striped dolphin indeterminate, with 4 occurring in Scotland, and 4 in Wales (Tables 2 & 3, Map 5). Numbers of these records vary from year to year depending upon the condition and accessibility of specimens. In terms of general body size and shape, short-beaked common and striped dolphins are quite similar. Once decomposition or scavenging has destroyed identifiable external characteristics, distinguishing between the two species can be difficult. Fortunately, the short-beaked common dolphin has two well-defined palatal grooves on the ventral surface of the rostrum that are absent in the striped dolphin. These can usually be identified through touch, by applying gentle pressure to the roof of the mouth. Long-finned pilot whale (Globicephala melas) Only 5 long-finned pilot whales were recorded in 2004, the same total as in 2003 (Tables 2 & 3, Map 6, Appendix 2.3). Numbers of these animals vary from year to year, although data for 2003-2004 show a reduction compared with 2001 (n = 27) and 2002 (n = 21). The distribution of long-finned pilot whales reported in 2004 is comparable with that of recent years, being predominantly along the western coasts of Britain from the Western Isles to Cornwall (see Appendix 2.3). The distribution data for 2004 accord with the historic sightings data for this species in UK waters (see Evans, 1995). Risso’s dolphin (Grampus griseus) Ten reports were received for Risso’s dolphin in 2004 (Tables 2 & 3, Map 6). Though slightly higher than 2003 (n = 7), this figure is comparable with those of recent years. Eight of the reports came from Scotland and two from Cornwall (see Appendix 2.4). The strandings distribution data are consistent with sightings data for the UK (northern and western coasts; see Reid et al, 2003; p. 49), although two of the reports made to the NHM came from the east coast of Scotland (Dornoch and Aberdeen) where Risso’s dolphins are seen less frequently. On 8th April 2004, a female Risso’s dolphin 2.40 metres in length was found washed ashore at Trevone Bay, near Padstow, Cornwall (SW.2004/139a, Plates 5 & 6). The carcass was beginning to decompose, but clear rope marks approximately 1 centimetre in diameter and fine net marks around the tailstock could be seen.
Plates 5 & 6. Left: Female Risso’s dolphin – (SW.2004/139a), washed ashore at Trevone Bay, Cornwall, 08 April 2004. Right: Detail of rope and net marks around tailstock. Photographs: Nick Darke; courtesy of Cornwall Wildlife Trust.
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The range of lengths for adults of this species is 2.8 to 3.3 metres, with neonatal length of 1.2 to 1.5 metres. Five of the seven 2004 specimens measured were of adult length. The two remaining specimens were both 2.40 metres in length (SW.2004/139a and 219a). NHM data for 2004 show Risso’s dolphins present in UK waters through much of the year, a finding which is consistent with recent years. White-sided dolphin (Lagenorhynchus acutus) Five records were received for this species in 2004, compared with 12 in 2003 (Tables 2 & 3). Map 7 shows the distribution of white-sided dolphin strandings for 2004. All 5 strandings occurred along the northern and western coasts of Scotland from May to December. The locations and dates of stranding are comparable with sightings data, with an occurrence to the west of the Northern Isles and the Outer Hebrides from July to September (see Evans, 1995; p.17). The range of lengths given for adult white-sided dolphins is 2.0 to 2.8 metres (Evans, 1995). Of the 5 animals whose lengths were recorded, 4 were adult length (Appendix 2.5). White-beaked dolphin (Lagenorhynchus albirostris) Nine records were received for this species in 2004, consistent with records for previous years (Tables 2 & 3). Map 7, shows the distribution of strandings for 2004, with 6 records received from the northern coasts of Scotland and three from the Yorkshire coast (Appendix 2.6). This distribution is consistent with data from previous years and supports recent sightings data (Reid et al, 2003; p. 45). The range of lengths for adult white-beaked dolphins is 2.5 to 2.7 metres, with neonatal length of 1.2 to 1.6 metres (Evans, 1995; p.17). Two of the nine animals whose lengths were recorded were of neonatal length; two were of adult length with the remainder ranging from 1.76 to 2.42 metres long (see Plate 8 and Appendix 2.6). White sided / white beaked dolphin species indeterminate A single record was received in 2004 – a very decomposed dolphin, genus Lagenorhynchus found at Alnmouth, Northumberland, 30th October 2004 (SW.2004/330; Map 7). The animal had been dead for a considerable time. Examination of the carcass by the Environment Agency showed many teeth were broken, the dorsal fin and pectoral flippers were missing and the tail flukes were absent. Much of the damage may have been the result of scavenging and decomposition processes. Despite the condition of the carcass, it was possible to confirm identification as Lagenorhynchus. Species identification could not be confirmed. Distribution data cannot be used to aid identification, as both the white-sided and white-beaked dolphin are found in the North Sea. Sightings of white-beaked dolphins are much more common in this region (Reid et al, 2003; p. 45).
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Striped or euphrosyne dolphin (Stenella coeruleoalba) In 2004, 6 striped dolphins were reported to the NHM (Tables 2 & 3), compared with 12 in 2003. Two of these were from Scotland, 1 from Wales and 3 from England (see Appendix 2.7). The strandings occurred from February to November. The distribution of striped dolphin strandings for 2004 can be seen in Map 8, and is similar to those recorded in recent years.
Plate 7. Striped dolphin – (SW.2004/249), stranded at Housel Bay, the Lizard, Cornwall on 08 August 2004. Photograph: Caroline Curtis; courtesy of Cornwall Wildlife Trust. Data held by the NHM show that most strandings of this species occur along the western coasts of the UK, from Shetland to Cornwall. Live sightings of striped dolphins off the Atlantic seaboard of the UK are rare (Evans, 1995; p.21), but sightings records do exist for this species in coastal UK waters, mainly between July and September. One specimen, a male, 1.82 metres in length (SW.2004/249) was found washed ashore at Housel Bay, Lizard, Cornwall on 8th August 2004 (Plate 7). The range of lengths given for adult striped dolphins is 1.95 to 2.4 metres and 1.0 metre for newborn animals (Evans, 1995; p.21); given these criteria, none of the animals recorded as stranded in 2004 were of adult length (Appendix 2.7). Bottlenose dolphin (Tursiops truncatus) In 2004, 8 bottlenose dolphins were reported to the NHM (Tables 2 & 3), a figure consistent with those of previous years. Distribution of strandings ranged from the east coast of England (Humber), the north east coast of Scotland and Northern Ireland and the south west coast of England (Map 8 and Appendix 2.8). The strandings occurred from June to December 2004. The sightings data for the bottlenose dolphin outlined by Reid et al (2003; p. 37) are generally supported by the NHM’s strandings data. The maximum length given for this species in the eastern North Atlantic is 3.81 metres for males and 3.50 metres for females (Perrin and Reilly, 1984). Neonatal length is given as 0.98 to 1.30 metres (Evans, 1995). Appendix 2.8, shows the sex and length data for bottlenose dolphins stranded around the UK in 2004; only two animals were of adult length.
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Unidentified dolphins There were 55 unidentified dolphins reported to the NHM in 2004, a decrease of more than 50% compared to 2003 (n = 114; Tables 2 & 3). These reports relate to carcasses too decomposed, incomplete or inaccessible for examination and retrieval. The majority of these reports relate to carcasses washed up around southwest England (Cornwall, Devon and Dorset) from January to May 2004, although 12 were reported from the Western Isles of Scotland (see Map 5). As with recent years, it is highly likely that many of the carcasses washed up around the south west of England in the same period were those of short-beaked common dolphins, relating to the seasonal increase in numbers of this species seen in the early months of the year. However, it is noteworthy that there was not a corresponding increase in the number of short-beaked common dolphins reported stranded around the Western Isles for the same period. Unfortunately, lack of descriptive data for these strandings prevented further interpretation or attempts to identify which species may have been represented. Harbour porpoise (Phocoena phocoena) In 2004, 472 strandings of harbour porpoise were reported to the NHM (Table 2 & Figure A6), an increase of 151 compared with 2003 (n = 321). This total is significantly higher than previous years and represents the highest total on record. Since 1993, annual numbers of harbour porpoise strandings have steadily increased (Table 3), making them the most common cetacean species to strand in UK waters. In recent years, harbour porpoises have represented approximately half of all cetaceans reported annually, but in 2004, this proportion rose to 59.07% (Figure A6). In England and Wales, 384 animals were recorded for 2004 (2003 = 244; Appendix 3.1), whilst for Scotland, the total was 83 (2003 = 73; Appendix 3.2). Five records were also received from Northern Ireland (Figure A7; Map 9; Appendix 3.3). Increased levels of strandings were reported in all areas used to analyse annual data (i.e. Cornwall +74, Devon +10, rest of England +50, Wales +16, Scotland +10 and Northern Ireland +1 – see Figure A7). However, the area that saw the largest increase was Cornwall, where 90 porpoises were reported in the period January to April 2004. This compares with only 22 in the same period for 2003. The annual summer peak in strandings of this species noted by Muir et al. (1999), thought to be associated with the peak months for parturition, is most visible for Wales, but is less apparent for the rest of the UK. The majority of stranding reports relating to porpoises from the rest of England (see Figure A7) came from the North Sea and English Channel coasts, from Northumberland to West Sussex, although 34 reports were received from Merseyside, primarily in the period April to July 2004. Figure A7 also shows the increase in numbers of harbour porpoise reported stranded around the south west of England during the winter months. For Scotland, an increase in numbers can be seen from January to July 2004.
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Figure A6. Total numbers of reported UK cetacean strandings etc., 1990 – 2004, compared with annual numbers of harbour porpoise.
Figure A7. Strandings etc. of harbour porpoise by month for 2004
0
10
20
30
40
50
60
70
Jan Feb M ar Apr M ay Jun Jul Aug Sep O ct Nov Dec
C ornwall D evon R est of England W ales Scotland N . Ire land
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Figure A8, shows the number of harbour porpoise stranded by month from 1998 to 2004. The increase in birth-length individuals reported during the summer months is reflected here. Figure A8. Cumulative monthly totals of harbour porpoise stranded in the UK, 1998-2004
0
5 0
1 0 0
1 5 0
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2 5 0
J a n F e b M a r A p r M a y J u n J u l A u g S e p O c t N o v D e cM o n t h
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Figure A9, shows the range of lengths recorded by month for the harbour porpoise from 1998 to 2004:
Figure A9. Harbour porpoise, length by month 1998-2004
0
0.5
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th in
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Female Male gender unknown .
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
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The range of lengths given for adult harbour porpoise are 1.35 to 1.80 metres, and 0.67 to 0.90 metres for new-born animals (Evans, 1995; p.21). The cumulative length data in Figure A9, show an increase in the number of harbour porpoise in the range 0.5 to 1.0 metres from April through to September, with a peak occurring between May and August. These data can be taken to represent an increase in the number of newborn animals, and confirm the summer months as the peak time for parturition in this species.
Plate 8. White-beaked dolphin (top) – (SW.2004/91b), male, 1.76 metres long, stranded at Saltburn Sands, Saltburn-by-the-Sea, North Yorkshire on 27 February 2004 and (bottom) harbour porpoise – (SW.2004/91a), female, 1.25 metres long, stranded at Redcar beach, Redcar, North Yorkshire on 26 February 2004. Photograph: Redcar & Cleveland Borough Council. Sperm whale (Physeter catodon) In 2004, 3 sperm whale strandings were reported to the NHM compared with 8 in 2003 (Tables 2 & 3). This is the lowest number recorded since 1991 (n = 1). Two of the strandings were from England (January and March) and one from Scotland (December; see Appendix 2.9). In 2004, two sperm whales were found stranded on the coasts of Norfolk and Lincolnshire (Appendix 2.9) at similar times of the year and in close proximity to two strandings which took place in 2003. It is uncommon to find sperm whales in the North Sea. They are usually found in waters deeper than 200 metres (Reid et al. 2003, p. 25) and it is possible that the animals stranded in 2004 may have entered the North Sea by mistake, rather than passing west around the north coast of Scotland into much deeper waters. Weakness from a lack of food together with the effects of extremely tidal inshore waters may have been responsible for many of these sperm whales beaching, either alive or when already dead. As with previous years, the sex of the animals stranded and examined in 2004 was male.
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Plate 9. Sperm whale - (SW.2004/38), male, 18 metres long, stranded at Thornham beach, Norfolk on 29 January 2004. Photograph: Adam Rowlands, Titchwell Marsh RSPB Reserve. Sperm whales are most often sighted in British and Irish waters between July and December, although some evidence suggests that they may remain in high latitudes into the winter months (Berrow et al. 1993; Evans 1997). The range of lengths given for adult sperm whales is approximately 8.3 to 11.00 metres for females and 11.0 to 16.0 metres for males (Evans, 1995, p.15; Whitehead, 2002, p. 1165). Using these criteria and given the lengths recorded for the 2004 specimens, they may be classified as physically mature males (Appendix 2.9). Northern bottlenose whale (Hyperoodon ampullatus) Only two records were received by the NHM for this species in 2004. Numbers of northern bottlenose whales stranded around the UK each year are typically low (see Table 3), and in some years they are not recorded at all. On the 29th March 2004, the NHM received a report from H.M. Coastguard relating to a cetacean which had been found stranded at Heysham Sands, Heysham, Lancashire, earlier the same day (Map 11). The local authority was given as a contact and it was discovered upon receipt of photographs (Plate 10) that the animal was in fact a male northern bottlenose whale, 4.50 metres long and in very good condition (SW.2004/125). Unfortunately, by the time the report had been made to the NHM, and condition/identification verified, the carcass had already been cleared and disposed of, preventing any form of detailed examination.
Plate 10. Northern bottlenose whale – (SW.2004/125), male, 4.50 metres long, stranded at Heysham sands, Heysham, Lancashire on 29 March 2004. Photograph: Alex Bottomley.
On the 1st August 2004, a report was received from H.M. Coastguard relating to the carcass of a medium-sized cetacean 4.57 metres long, seen floating in the River Ouse, near the M62 flyover, Humberside. It was described initially as a
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decomposing minke whale, and was not found during subsequent searches. However, over the following two weeks, the carcass was seen at various points in the Ouse, the Aire and finally on the north shore of the Humber at Oyster Ness, where a member of the public was able to take photographs which confirmed identification as northern bottlenose whale (SW.2004/239). Sightings and strandings of northern bottlenose whales in the English Channel, Channel Approaches, Irish Sea and North Sea are uncommon. In recent years strandings have occurred on the coasts of South Devon (2003, n = 1), Orkney and Strathclyde (2001, n = 3). Adult females are up to 8.7 metres in length, adult males up to 9.8 metres and at birth calves are about 3.5 metres (Leatherwood et al. 1993, p. 85). Given these criteria, both of the animals stranded in 2004 were young/immature specimens (see Appendix 2.10). Sowerby’s beaked whale (Mesoplodon bidens) Three reports of stranded Sowerby’s beaked whales were received in 2004 (Tables 2 & 3), one from Highland, one from Londonderry and one from Ceredigion (Map 11). Strandings and sightings of Sowerby’s beaked whales are usually recorded along the north and east coasts of Scotland. However, occasional strandings have occurred along the east and southwest coasts of England and the Welsh coast in recent years (Appendix 2.11). Eight of the eleven strandings reported since 2000 have been female, with strandings occurring primarily in the latter half of the year (June to September). The most notable stranding of this species in 2004 took place at Ynys-Lochtyn, Ceredigion, Wales on 27th September. A male Sowerby’s beaked whale, 3.96 metres long stranded alive (SW.2004/289), was examined and successfully returned to the sea. On the 28th September the animal stranded again at nearby Newport (Parrog) in Pembrokeshire, was returned to the sea where it later died and was subsequently washed back to shore. Note: post mortem results were logged using the reference SW.2004/290. Cuvier’s beaked whale (Ziphius cavirostris) Two reports were received for this species in 2004 (Tables 2 & 3), both from the western coasts of Scotland (Map 11 & Appendix 2.12). Cuvier’s beaked whale is one of the less-common species occurring in UK waters, and is often absent from NHM annual strandings data. In the past 15 years, strandings have been recorded on the north and west coasts of Scotland, the west coast of Wales, the east and southwest coasts of England. Records since 2000 show strandings of this species occurring throughout the year (Appendix 2.12). Unidentified odontocetes and other cetaceans In 2004, the NHM received 16 reports of unidentified toothed cetaceans (odontocetes) from around the UK, and a further 11 reports of carcasses not identified as toothed or baleen whales (see Map 12). It is often difficult to identify such carcasses owing to their inaccessibility, incompleteness or to their advanced state of decomposition.
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Part B
UK Cetacean and Marine Turtle Post-mortem Investigations 2004
Post-mortem investigations of UK marine mammal strandings have been co-ordinated in England and Wales by the Institute of Zoology (IoZ) at the Zoological Society of London since 1990 and in Scotland by the Scottish Agricultural College in Inverness (SAC) since 1992. More recently, marine turtle examinations have been included in the remit. Both IoZ and SAC liaise closely with the Natural History Museum, London (NHM). Tissue samples collected from post-mortem examinations of UK-stranded marine mammals and turtles are archived by IoZ, SAC and NHM. The Poseidon central strandings database is held jointly by IoZ and SAC and stores pathological and other data derived from the post-mortem investigations of UK-stranded marine mammals. Most of the data currently held in the Poseidon database was generated under contract to Defra, although some data was generated independently by research collaborations with non-Defra-funded individuals or organisations. During 2004, 235 stranded or bycaught cetacean carcasses and one marine turtle carcass were examined at post-mortem in the UK (Table A). Of these, 68 carcasses were examined in Scotland (Table B) and 168 were examined in England and Wales (Table C). The number of cetacean post-mortem examinations conducted in 2004 is considerably greater than the number conducted in 2003 (n=184) and 2002 (n=189). Table A: UK Cetacean and Marine Turtle Post-mortem Investigations during 2004
Results of UK cetacean and marine turtle post-mortem examinations conducted in 2004
Causes of death Table D summarises the causes of death of 235 cetaceans and 1 marine turtle examined at post-mortem in the UK in 2004. It was not possible to establish the cause of death of 12 UK-stranded harbour porpoises, 5 bottlenose dolphins, 4 short-beaked common dolphins and 1 striped dolphin. Causes of cetacean mortality Entanglement in fishing gear (Bycatch) Following post-mortem examination, 37 stranded harbour porpoise carcasses were diagnosed to have died due to bycatch in 2004. An additional 9 harbour porpoise carcasses were retrieved for post-mortem examination directly from fishing vessels as part of observer-based research co-ordinated by the Sea Mammal Research Unit (University of St. Andrews). Thirty-two UK-stranded short-beaked common dolphins were diagnosed as bycatches, of which 31 occurred within the south west of England (Cornwall, Devon and Dorset). Four of these common dolphins were retrieved floating at sea by a Greenpeace vessel off the Devon coastline near Plymouth. A single Risso’s dolphin stranded in Cornwall, England was also diagnosed as bycatch in 2004. The spatial distribution of these UK-stranded cetacean bycatches (excluding the harbour porpoises retrieved directly from fishing vessels) examined at post-mortem in 2004 are shown in Figure B1. Trends in harbour porpoise and short-beaked common dolphin strandings diagnosed as bycatches since 1990 in south west England (Cornwall and Devon) and other UK regions are discussed in more detail in the final report to Defra for this contract. Physical trauma (including fatal attack from bottlenose dolphins) Forty-one UK-stranded harbour porpoises, 2 common dolphins and 1 fin whale were found on post-mortem examination to have died due to physical trauma (excluding bycatch) during 2004. Of these, 37 harbour porpoises had lesions consistent with fatal attack from bottlenose dolphins comprising 23 from West Wales, 11 from Scotland (generally between the Moray Firth and Firth of Forth areas), and 3 from England (Devon/Cornwall) (Fig. B2). As in previous years, fatal attack from bottlenose dolphins (along with bycatch) was one of the most common causes of death diagnosed in UK-stranded harbour porpoises in 2004. The number of cases diagnosed in West Wales has increased almost annually since 1999 and the 23 cases diagnosed in 2004 is the highest number ever recorded in this region. A more detailed analysis of trends in harbour porpoises killed by bottlenose dolphins since 1990 is included in the final report to Defra for this contract. Four harbour porpoises stranded in Wales and a common dolphin in Essex, England had fatal traumatic injuries of unknown origin. A common dolphin stranded in Devon had traumatic injuries consistent with a boat propeller strike. The fin whale examined in the Port of Liverpool, Merseyside had traumatic injuries consistent with ship strike.
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Figure B1 Spatial distribution of 37 stranded harbour porpoises (excluding porpoises retrieved directly from fishing vessels) (red dots), 32 stranded (or floating at sea) short-beaked common dolphin (blue dots), and one Risso’s dolphin (yellow dot) diagnosed as bycatch in 2004.
Figure B2 Spatial distribution of 37 stranded harbour porpoises diagnosed as killed by bottlenose dolphins in 2004.
Infectious disease mortality During 2004, harbour porpoises (n=40), Risso’s dolphins (n=2), white beaked dolphins (n=2) and common dolphin (n=1) died due to fatal infectious diseases (Table D). In the harbour porpoises, these consisted of parasitic infections of the lungs resulting in severe airway obstruction, acute pulmonary haemorrhage, parasitic pneumonia or secondary bacterial or fungal infections (n=28), generalised bacterial infections (n=7), parasitic gastritis (n=2), bacterial enteritis/peritonitis (n=2) and mycotic otitis media (n=1). The Risso’s dolphins died of peritonitis (n=1) and meningoencephalitis (n=1), the white beaked dolphins of parasitic and secondary bacterial gastro-enteritis (n=1) and parasitic and bacterial pneumonia (n=1), and the common dolphin of a fatal bacterial pneumonia (n=1). There were no cases of distemper due to morbillivirus infection in any UK-stranded cetacean carcasses in 2004. Starvation Starvation was diagnosed as the cause of death in animals that were severely emaciated in the absence of any other underlying disease processes that could explain the poor nutritional status. The death of 17 harbour porpoises (including three neonates) and single cases of a common dolphin, a pilot whale and a white beaked dolphin were attributed to starvation.
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Live stranding Live stranding was diagnosed as the cause of death in animals that were known or suspected (from post-mortem examination) to have stranded alive while in apparent good health and nutritional status. The cause of death of diseased or emaciated animals that stranded alive was attributed to the disease process rather than the live stranding event. Live stranding was diagnosed as the cause of death in short-beaked common dolphins (n=6), harbour porpoises (n=5), striped dolphins (n=3), Atlantic white-sided dolphins (n=2), pilot whale (n=1), a Sowerby’s beaked whale (n=1) and a sperm whale (n=1). The juvenile pilot whale that live stranded in Scotland had skin lesions consistent with teeth marks from one or more bottlenose dolphins. Gas embolism A Sowerby’s beaked whale (Mesoplodon bidens) that stranded alive in Wales in September 2004 died of acute systemic gas embolism (Fig’s B3 and B4) and a harbour porpoise that stranded in Scotland in September 2004 died of chronic gas embolic lesions. Two additional common dolphins that died of bycatch had some chronic gas embolic lesions at earlier stages of development (the first found 50 miles off Plymouth, Devon by the Greenpeace ship Esperanza on 06/02/04 and the second found stranded in South Devon on 22/03/04). Similar cases have been found in a small number of single-stranded cetaceans in the UK in previous years (see Jepson et al. 2003, Fernandez et al. 2004, Jepson et al. 2005b). Further details of the stranded cetacean gas embolism cases found between 1992 and 2004 are described within the final report of this contract. Tumours One harbour porpoise that stranded in Wales had a suspected pulmonary tumour in 2004. The degree of decomposition of the carcass prevented a more specific diagnosis. Other causes of death The other remaining causes of death of the stranded cetaceans and marine turtle examined in 2004 are detailed in Table D.
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Figure B3. Stranded Sowerby’s beaked whale (SW2004/290) (Photo: Jeremy Jones).
Figure B4. SW2004/290. Photograph of kidney showing gas bubbles in inter-renicular veins (arrow).
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Table D: Causes of death of 235 UK-stranded cetaceans and one marine turtle
in 2004
Species Cause of death category No. Harbour porpoise Bycatch* 46 Physical trauma (bottlenose dolphin attack) 37 Pneumonia (parasitic/bacterial/mycotic) 28 Starvation (including 3 neonates) 17 Generalised bacterial infection 7 Live Stranding 5 Physical trauma (unidentified cause) 4 Gastritis, parasitic 2 Peritonitis and enteritis 2 Dystocia/stillbirth 2 Neoplasia (suspected) 1 Gas embolism 1 Otitis media (mycotic) 1 Peritonitis and metritis (sequel to dystocia?) 1 Not established 12 Short-beaked common dolphin Bycatch (including two with gas embolism) 32 Live Stranding 6 Physical trauma (unidentified/propeller) 2 Starvation 1 Pneumonia, Bacterial 1 Not Established 4 Bottlenose dolphin Not Established 5 Striped dolphin Live Stranding 3 Not established 1 Risso’s dolphin Bycatch 1 (Meningo) encephalitis 1 Peritonitis 1 White-beaked dolphin Gastro-enteritis (parasitic/bacterial) 1 Pneumonia (parasitic/bacterial) 1 Starvation 1 White-sided dolphin Live stranding 2 Long-finned pilot whale Live Stranding 1 Starvation 1 Sowerby’s beaked whale Live Stranding 1 Gas embolism 1 Fin whale Physical trauma (ship strike?) 1 Sperm whale Live Stranding 1 Loggerhead turtle Not Established 1
* Of the 46 harbour porpoise bycatches reported here, 9 were carcasses retrieved directly from fishing vessels as part of observer-based research conducted by the Sea Mammal Research Unit.
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Investigations of relationships between environmental contaminants and health status Toxicology data from UK-stranded harbour porpoises Tissue samples for toxicological analyses continued to be collected and archived from stranded marine mammals examined during 2004. A number of samples taken from stranded cetaceans (predominantly harbour porpoises) were sent to the CEFAS Burnham Laboratory, Essex (CEFAS) for toxicological analyses during 2004. Investigations of potential relationships between exposure to persistent environmental pollutants and health status in UK harbour porpoises continued in 2004 in collaboration with the Sea Mammal Research Unit (University of St Andrews) and the CEFAS Burnham Laboratory, Essex. The first case-control studies demonstrated significant associations between elevated blubber polychlorinated biphenyls (PCBs) levels and infectious disease mortality (compared to controls that died of acute physical trauma) and this association was not confounded by a range of factors including age, sex, stranding location and two quantitative indices of nutritional status (Jepson et al. 2005a). The second study took these analyses one step further and conducted a slightly different analysis to calculate the odds ratio for increased risk of infectious disease mortality from increasing levels of polychlorinated biphenyls (PCBs) in blubber (Hall et al., accepted for publication). These novel analyses may form the basis of future risk assessment-type analyses to predict the population level impacts of immunosuppressive pollutants in populations of known size and PCB exposure. A range of analyses of toxicological and pathological data generated in stranded harbour porpoises have been included in the final report to Defra for this research contract. These analyses include trends in contaminant exposure (organochlorine pesticides, chlorinated biphenyl congeners, heavy metals, butyltins and polybrominated flame retardants) in harbour porpoises stranded in the UK between 1989 and 2001 and investigations of potential relationships between exposure to these contaminants and health status in stranded harbour porpoises (see also Jepson 2003). Additional collaborative research activity A number of collaborative research activities were supported by access to data and/or tissue samples collated by the Defra-funded UK Cetacean and Turtle Strandings Programme. • A NERC-funded PhD studentship investigating the population structure of
harbour porpoises in UK waters using genetic (microsatellite) markers continued during 2004. The research is being supervised jointly by the Institute of Zoology and Cambridge University.
• Institute of Zoology (Zoological Society of London). A collaborative research
programme to develop population-based models for the dynamics of parasites and their mammalian hosts, utilising data from UK stranded cetaceans (specifically harbour porpoises), was initiated in 2004 in collaboration with Dr. Andrew Fenton and Dr. James Bull.
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• Professor Antonio Fernandez, Facultad de Veterinaria Universidad de Las Palmas de Gran Canaria, Spain. Pathological investigations into gas and fat embolism in cetaceans.
• Dr. Simon Northridge, Sea Mammal Research Unit, Gatty Marine Laboratory,
University of St. Andrews, St Andrews, Fife. Teeth and stomach contents from cetaceans stranded in England and Wales are routinely sent for teeth ageing and stomach content analysis respectively. This biological data from stranded cetaceans forms an integral part of additional Defra-funded research on cetacean bycatch co-ordinated by the Sea Mammal Research Unit.
• Dr. Ailsa Hall, Sea Mammal Research Unit, Gatty Marine Laboratory, University of
St. Andrews, St Andrews, Fife. Risk assessment analyses of impacts of polychlorinated biphenyls (PCBs) on populations of harbour porpoises.
• Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik,
Midlothian, EH26 0PZ, Scotland. Expert neurohistopathological studies on cetacean tissues from Scottish cetaceans.
• Dr. Graham Pierce, University of Aberdeen, Department of Zoology, Lighthouse
Field Station, George Street, Cromarty, Ross-shire IV11 8YJ. Collaboration on life history, dietary and toxicological studies of harbour porpoises and other cetaceans (including internationally collaborative EU-funded BIOCET project completed in 2005).
• Dr. Paul Thompson, University of Aberdeen, Department of Zoology, Lighthouse
Field Station, George Street, Cromarty, Ross-shire IV11 8YJ. Collaboration on biological studies of harbour porpoises and bottlenose dolphins.
• Dr. Krishna Das, Laboratory for Oceanology, MARE Center, B6c, Liège
University, B-4000 Liège, Belgium/Dr. Ursula Siebert, Forschungs- und Technologiezentrum Westkueste Hafentoern D-25761 Buesum Germany. A collaboration with these two research institutes was established in 2004 to investigate potential thyrotoxic histopathological effects of persistent organic pollutants (such as PCBs) on thyroid microanatomy.
• Dr. Ursula Siebert, Forschungs- und Technologiezentrum Westkueste Hafentoern
D-25761 Buesum Germany. On 1st October 2004, the Institute of Zoology began a small (Defra-funded) 2-year project to examine the feasibility of using formalin-fixed auditory tissue (ears) collected from UK stranded cetaceans to investigate potential auditory impacts of anthropogenic noise exposure. The research is in collaboration with the Forschungs und Technologiezentrum Westkueste, Buesum, Germany.
• Dr. Seamus Kennedy, Veterinary Sciences Division, Department of Agriculture for
Northern Ireland, Stormont, Belfast. Immunoperoxidase screening for the presence of morbillivirus antigen in fixed samples of cetacean lung and other tissues.
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• Dr Andrew Kitchener, Royal Museum of Scotland, Edinburgh, Scotland. Recording all marine mammal stranding events in Scotland. Marine mammal skulls and scapulae are sent to Dr. Kitchener for marine mammal morphometric studies.
• Dr Alistair MacMillan, Brucella Section, Veterinary Laboratories Agency, New Haw,
Addlestone, Surrey, KT15 3NB. Serological studies to assess exposure to Brucella spp. and typing of Brucella isolates.
• Dr Jacques Godfroid, Centre d'etude et de la Recherches Veterinaires et
Agronomiques, B-1180 Brussels, Belgium. Molecular typing of Brucella isolates. • Professor David Collins, University of Reading, Reading RG6 6AP. Sequencing of
novel bacterial isolates. Scientific Meetings attended The Technical Co-ordinator of scientific research (Dr Paul Jepson) also attended the following meetings in relation to the impacts of anthropogenic noise on marine mammals:-
• US Marine Mammal Commission Technical Workshop on “Understanding the impacts of anthropogenic noise on beaked whales” held in Baltimore, USA (April 2004)
• Marine Board & National Science Foundation workshop on impacts of noise on marine mammals in US waters (September 2004)
• An International Workshop (US Marine Mammal Commission/UK JNCC) on Policy on Sound and Marine Mammals (September 2004)
• A Defence Science and Technology Laboratory (Dstl) beaked whale workshop in London (October 2004)
• International Whaling Commission Workshop on Habitat Degredation in Italy (November 2004)
• Dstl beaked whale workshop held at the Sea Mammal Research Unit (St Andrews University) (November 2004)
Additional Report writing Dr Paul Jepson authored a 2004 report to the UK Defence Science and Technology Laboratory (Dstl) on “In vivo gas bubble disease in cetaceans”. Lawson, B. and Jepson, P.D. (compilers) (2004) UK Phocine Distemper Virus Epizootic: Investigation Report 2002/2003. Report to the Department for Environment, Food and Rural Affairs. 221pp. Student theses The following student thesis was completed in 2004 using samples and/or data collated by the UK Marine Mammal Strandings Research Programme.
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• Ssuna, R. (2004) Investigating the relationship of polychlorinated biphenyls in blubber with levels of nematode infestations and cause of death in harbour porpoises (Phocoena phocoena). Submitted in part fulfilment of the requirements for the degree of Master of Science in Wild Animal Health, University of London, 2004
2004 Publications Dawson, C.E., Perrett, L.L., Davison, N.J., Quinney, S., Simpson, V.R., (2004) Brucella infection in marine mammals off the Cornish coast. Veterinary Record 155, 32 Drout, V., Berube, M., Gannier, A., Goold, J.C., Reid, R.J. and Palsboll, P.J. (2004) A note on genetic isolation of Mediterranean Sperm Whales, Physeter macrocephalus, suggested by mitochondrial DNA. Journal of Cetacean Research and Management 6(1) 29-32 Lawson, B. and Jepson, P.D. (compilers) (2004) UK Phocine Distemper Virus Epizootic: Investigation Report 2002/2003. Report to the Department for Environment, Food and Rural Affairs. 221pp. Fernandez, A., Arbelo, M., Deaville, R., Patterson, I.A.P., Castro, P., Baker, J.R., Degollada, E., Ross, H.M., Herráez, P., Pocknell, A.M., Rodriguez, E., Howie, F.E., Espinosa, A., Reid, R.J., Jaber, J.R., Martin, V., Cunningham, A.A., and Jepson, P.D. (2004) Whales, sonar and decompression sickness (reply). Nature, doi:10.1038/nature02528 Foster, G., Holmes, B, Steigerwalt, A. G., Lawson, P. A., Thorne, P., Byrer, D. E., Ross, H. M., Xerry, J., Thompson, P. M. and Collins, M. D. (2004) Campylobacter insulaenigrae sp. nov., isolated from marine mammals. International Journal of Systematic and Applied Microbiology 54:2369-2373. Holt, W.V., Waller, J., Moore, A., Jepson, P.D., Deaville, R. and Bennett, P.M. (2004) Smooth muscle actin and vimentin as markers of testis development in the harbour porpoise (Phocoena phocoena). Journal of Anatomy 204, 201-211. Perrett ,L.L., Dawson, C.E., Davison, N., Quinney, S. (2004) Brucella infection of lungworms from a harbour porpoise. Veterinary Record 154, 800 Pierce, G.J., Santos, M.B., Reid, R.J., Patterson, I.A.P. and Ross, H.M. (2004) Diet of minke whales Balaenoptera acutorostrata in Scottish (UK) waters with notes on stranding of this species in Scotland 1992-2002. J. Mar. Biol. Ass. 84, 4757/1-4 Santos, M.B., Pierce, G.J., Learmonth, A., Reid, R.J., Ross, H.M., Patterson, I.A.P., Reid, D.G. and Bearec, D. (2004) Variability in the diet of harbour porpoises (Phocoena phocoena) in Scottish waters 1992-2003. Marine Mammal Science 20(1): 1-27 Wilson B., Reid R.J., Grellier K., Thompson P.M., Hammond P.S. (2004) Considering the temporal when managing the spatial: a population range expansion
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impacts protected areas-based management for bottlenose dolphins. Animal Conservation 7: 331-338. References Berrow, S., Evans, P.G.H. and Sheldrick, M. (1993) An analysis of sperm whale Physeter macrocephalus stranding and sighting records from Britain and Ireland. J. Zool., Lond., 230, 333-337. Christensen, I. (1980) Catch and effort in the Norwegian minke whale fishery in the 1978 whaling season. Report of the International Whaling Commission 30: 209-212. Evans, W.E. (1994) The Handbook of Marine Mammals Vol.5 – the First Book of Dolphins. S. Ridgway and R. Harrison (eds). Academic Press, London. Evans, P.G.H. (1992) Status Review of Cetaceans in British and Irish Waters. Report to the UK Department of the Environment. UK Mammal Society Cetacean Group, Oxford. Evans, P.G.H. (1995) Guide to the Identification of Whales, Dolphins and Porpoises in European Seas. Sea Watch Foundation Publication, Oxford, 1995. Evans, P.G.H. (1997) Ecology of sperm whales (Physeter macrocephalus) in the Eastern North Atlantic, with special reference to sightings and strandings records from the British Isles. In Sperm Whale Deaths in the North Sea: Science and Management (eds T.G. Jacques and R.H. Lambertsen), pp. 37-46. Bull. de L’Institut Royal des Sciences Naturelles de Belgique. Biologie. Vol. 67 – Supplement. Fernandez, A., Arbelo, M., Deaville, R., Patterson, I.A.P., Castro, P., Baker, J.R., Degollada, E., Ross, H.M., Herráez, P., Pocknell, A.M., Rodriguez, E., Howie, F.E., Espinosa, A., Reid, R.J., Jaber, J.R., Martin, V., Cunningham, A.A., and Jepson, P.D. (2004) Whales, sonar and decompression sickness (reply). Nature, doi:10.1038/nature02528 Fernández, A., Edwards, J. F., Rodríguez, F., Espinosa de los Monteros, A., Herráez, P., Castro, P., Jaber, J. R., Martín, V. and Arbelo, A. (2005) ‘‘Gas and Fat Embolic Syndrome’’ Involving a Mass Stranding of Beaked Whales (Family Ziphiidae) Exposed to Anthropogenic Sonar Signals. Veterinary Pathology, 42:446–457 Hall, A.J., Hugunin, K., Deaville, R., Law, R.J., Allchin, C.R., Jepson, P.D. The risk of infection from polychlorinated biphenyl exposure in harbour porpoise (Phocoena phocoena) – A case-control approach. Environmental Health Perspectives (accepted for publication) Jepson, P.D. (2003) Pathology and toxicology of stranded harbour porpoises (Phocoena phocoena) in UK waters. PhD thesis. Royal Veterinary College (University of London). Pp.1-221. July 2003.
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Jepson, P.D., Arbelo, M., Deaville, R., Patterson, I.A.R., Castro, P., Baker, J.R., Degollada, E., Ross, H.M., Herráez, P., Pocknell, A.M., Rodriguez, E., Howie, F.E., Espinosa, A., Reid, R.J., Jaber, J.R., Martin, V., Cunningham, A.A., and Fernandez, A. (2003) Gas-bubble lesions in stranded cetaceans. Nature, 425, 575-576 Jepson, P.D., Bennett, P.M., Deaville, R., Allchin, C.R., Baker J.R. & Law, R.J. (2005) Relationships between PCBs and health status in UK-stranded harbour porpoises (Phocoena phocoena). Environmental Toxicology and Chemistry 24, 238–248 Jepson, P.D., Deaville, R., Patterson, I.A.R., Pocknell, Ross, H.M., Baker, J.R., Howie, F.E., Reid, R.J., Colloff, A. and Cunningham, A.A. (2005b) Acute and chronic gas bubble lesions in cetaceans stranded in the United Kingdom. Veterinary Pathology 42: 291-305 Muir, A.I., Chimonides, P.D.J. & Spurrier, C.J.H. (1999) Trends in Cetacean Strandings on the British Coastline, 1998. The Natural History Museum, London. Perrin, W.F. & Reilly, S.B. (1984) Reproductive parameters of dolphins and small whales of the family Delphinidae. In: Reproduction in Whales, Dolphins and Porpoises (Eds W.F. Perrin, R.L. Brownwell and D.P. DeMaster) pp.97-133. Rep. Int. Whal. Comm, Spec. Issue No. 6, Cambridge. Reid, J. B., Evans, P. G. H. and Northridge, S. P. (2003) Atlas of Cetacean Distribution in North-West European Waters. Joint Nature Conservation Committee. Whitehead, H. (2002) Sperm whale Physeter macrocephalus. In: Encyclopedia of Marine Mammals (Eds W.F. Perrin, B. Wursig and J.G.M Thewissen) p. 1165. Academic Press.
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Appendix 1. UK cetacean distribution maps (all categories reported) by species, 2004
Map 1. All UK records of cetacean strandings and other categories, 2004
2004/28c 18/01/2004 Western Isles - - 2004/118b 22/03/2004 Western Isles - 5.50 2004/212c 02/07/2004 Highland F 2.86 2004/274a 13/09/2004 Highland M 4.89 2004/361 23/11/2004 Cornwall - 2.68
2.4. Risso’s dolphin
SW. number
Date of stranding
County/Region Sex Total length (metres)
2004/28b 18/01/2004 Orkney Islands - - 2004/54c 01/02/2004 Western Isles - - 2004/139a 08/04/2004 Cornwall F 2.40 2004/143b 10/04/2004 Cornwall F - 2004/169c 22/05/2004 Orkney Islands - 3.04 2004/219a 08/07/2004 Western Isles M 2.40 2004/228a 20/07/2004 Strathclyde - 3.00 2004/320a 18/10/2004 Highland - 3.00 2004/332c 01/11/2004 Grampian F 3.25 2004/338c 19/11/2004 Highland M 3.29
2.5. White-sided dolphin
SW. number
Date of stranding
County/Region Sex Total length (metres)
2004/164c 08/05/2004 Shetland Islands F 2.16 2004/187a 14/06/2004 Western Isles - 2.20 2004/196b 20/06/2004 Highland - 1.80 2004/244b 06/08/2004 Highland M 2.64 2004/361a 24/12/2004 Strathclyde - 2.40
2.6. White-beaked dolphin
SW. number
Date of stranding
County/Region Sex Total length (metres)
2004/82d 14/02/2004 Grampian M 2.00 2004/91b 27/02/2004 North Yorkshire M 1.76 2004/123 25/03/2004 North Yorkshire F 2.42 2004/123g 25/03/2004 Orkney Islands - 2.00 2004/192b 17/06/2004 Orkney Islands - 1.18 2004/206d 28/06/2004 Highland - 2.60 2004/235a 27/07/2004 Highland M 1.35 2004/245a 07/08/2004 Humberside - 2.40 2004/285a 22/09/2004 Highland - 2.70
2.7. Striped dolphin
SW. number
Date of stranding
County/Region Sex Total length (metres)
2004/66 04/02/2004 Dorset F 1.88 2004/82a 13/02/2004 Cornwall - 1.83 2004/125f 31/03/2004 Orkney Islands F 1.52 2004/225 16/07/2004 Pembrokeshire M 1.84 2004/249 08/08/2004 Cornwall M 1.82 2004/335 12/11/2004 Highland M 1.80
2.8. Bottlenose dolphin
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SW. number
Date of stranding
County/Region Sex Total length (metres)
2004/210 29/06/2004 Cornwall F 1.55 2004/216d 04/07/2004 Grampian M 1.94 2004/240b 02/08/2004 Tayside M 1.36 2004/257a 20/08/2004 Highland M 3.27 2004/280 16/09/2004 Devon - 1.93 2004/299b 03/10/2004 Antrim - 2.60 2004/321a 20/10/2004 Humberside M 3.50 2004/362 26/12/2004 Cornwall M 2.58
2.9. Sperm whale
SW. number
Date of stranding
County/Region Sex Total length (metres)
2004/38 29/01/2004 Norfolk M 18.00 2004/112 21/03/2004 Lincolnshire M 12.80 2004/342a 07/12/2004 Western Isles M 16.10
2.10. Northern bottlenose whale 2000-2004
SW. number
Date of stranding
County/Region Sex Total length (metres)
2000/47b 12/03/2000 Western Isles - 6.70 2001/73b --/04/2001 Orkney Islands - - 2001/124a 04/09/2001 Strathclyde F 5.80 2001/127b 09/11/2001 Orkney Islands F 7.50* 2003/390 04/12/2003 Devon - - 2004/125 29/03/2004 Lancashire M 4.50 2004/239 01/08/2005 Humberside F? 4.57
2.11. Sowerby’s beaked whale 2000-2004
SW. number
Date of stranding
County/Region Sex Total length (metres)
2000/2b 07/01/2000 Fife F 4.14 2000/64a 22/03/2000 Orkney Islands - 4.37 2000/150b 08/09/2000 Lincolnshire F 4.98* 2001/81e 14/04/2001 Highland F 4.50 2001/156a 15/07/2001 Orkney Islands - 4.00* 2001/210b 18/09/2001 Highland F 4.59 2002/201 07/06/2002 Cornwall F 4.44 2003/280a 04/07/2003 Highland F 4.73 2004/240c 04/08/2004 Highland F 3.78 2004/287 24/09/2004 Londonderry F - 2004/289 27/09/2004 Ceredigion M 3.96
2.12. Cuvier’s beaked whale 2000-2004
SW. number
Date of stranding
County/Region Sex Total length (metres)
2002/125a 18/03/2002 Strathclyde F 6.25 2002/222 20/06/2002 Norfolk M 5.65 2002/247 07/07/2002 Cornwall - 5.00* 2003/401i 18/12/2003 Western Isles - - 2004/36a 26/01/2004 Strathclyde - - 2004/170b 23/05/2004 Western Isles F -
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Appendix 3. Stranded cetacean species by region, UK, 2000-2004 3.1. Numbers of cetacean species reported stranded around England, Wales and Isle of Man, 2000 - 2004
