the south west dolphin report 2007

Standing up for Marine Wildlife

The South West Dolphin Report

A joint publication by the Marine Connection & The Wildlife Trusts

© 2007

Cetacean Sightings & Strandings in the South West of England - Summary


SummaryThe sea around south-west England is one of the UK’s four dolphin hotspots. 14 species of whale, dolphin and porpoise are seen here, from the familiar bottlenose dolphin to more unusual species such as the killer whale and sei whale.14 years of research by the Devon and Cornwall Wildlife Trusts have been compiledto create a Dolphin Map for the south-west coast, showing the best locations andtimes of year to observe the region’s dolphins. The research has also highlightedchanges through the years, including a dramatic increase in the number of deaddolphins being washed ashore. These changes may have serious implications forthe future of the South West as England’s ‘dolphin coast’.

A full report of this study is available by request to either Marine Connection or The Wildlife Trusts. It can also be downloaded from both websites: www.marineconnection.org and www.wildlifetrusts.org

IntroductionThe seas around the UK are home to 28 species of whale, dolphin and porpoise (known collectively as cetaceans). Some of these live here all year round, while others are occasional or seasonal visitors. The South West is England’s most important area for cetaceans, and one of the top four locations in the UK. A total of14 species are seen around this coast, from the harbour porpoise, Europe’s smallestcetacean, to the second largest animal on Earth – the fin whale. Dolphin-watching isa growing leisure activity in the region, and the presence of dolphins enhances theregion’s reputation for clean, healthy and unspoilt coast and seas.

Unfortunately, living as they do in close proximity to our shores, cetacean populations face a number of threats. These include entanglement in fishing gear,food shortages due to over-fishing, underwater noise from ships and industry,water pollution, and harassment by people observing them. Perhaps the greatest of these is entanglement or accidental capture in fishing gear, which is known as‘bycatch’. Bycatch accounts for thousands – possibly tens of thousands – of cetacean deaths worldwide each year. While much is still unknown about how and why bycatch occurs, and many fisheries are yet to be monitored, enough cases have been documented to establish the severity of the problem and the vulnerability of certain populations.

Bottlenose dolphins

Common dolphinCaroline Weir

Long-finned pilot whalesCaroline Weir

Risso’s dolphinsCaroline Weir

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In Devon and Cornwall, cetacean sightings are reported to Seaquest Southwest, a voluntary, self-funded coalition of marine organisations, run jointly by Devon and Cornwall Wildlife Trusts. Seaquest aims to gather information necessary forconservation and education. Seaquest currently consists of a team of over 350 volunteers that has been collecting data on sightings in Devon and Cornwall formore than 12 years. In Cornwall, data on stranded cetaceans is recorded by theCornwall Wildlife Trust Marine Strandings Network, a team of over 120 trained volunteers, which runs a 24-hour hotline. Devon Wildlife Trust is responsible forcoordinating the Devon strandings database and has a small group of volunteerswho record marine strandings. Data on species, sex, morphometrics, bycatch evidence (or other possible cause of death), location, wind direction and body condition are recorded and photographs are taken of each carcass. Both Cornwalland Devon Wildlife Trusts work in partnership with the Natural History Museum,which runs the UK Whale and Dolphin Stranding Scheme under which the recordsof all UK stranded cetaceans are collated. The results presented below are based ondata from 1990 to 2004.


Cetacean sightingsPublic recording schemes such as Seaquest are immensely important for cetaceanresearch and conservation. Cetaceans travel over huge distances and spend muchof their time underwater, which means that dedicated research is both difficult and expensive. Gathering reports of sightings from the public is a cost-effectiveapproach, making use of people’s growing awareness of cetaceans and their desireto help protect them. However, it is important to understand the limitations of thisapproach. Sightings data are just that. They only tell us where and when peoplehave encountered cetaceans, not where and when cetaceans have occurred. All sorts of factors can influence the likelihood of sightings being observed andreported, including the number of people visiting an area, the weather, the sea conditions and the observer’s awareness of the need to report their encounter.

Overall, sightings of cetaceans increased steadily from 1990 to 2004. This is thought to reflect the growing number of people taking an interest in cetaceans,rather than an increase in the number of cetaceans or frequency of their visits to coastal waters. The most consistent locations for viewing cetaceans were:Torbay, Plymouth, Falmouth, Mount’s Bay, Penzance, Land’s End, Cape Cornwall,the Isles of Scilly, St. Ives, Lundy Island and Morte Point.

Stranded common dolphin

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Sightings typically increase from February, rise to a peak from June to August, then decrease through autumn and winter. However, for some species (e.g. common dolphin) the seasonal trend is reversed, with more sightings in winter. The three species most commonly seen throughout the 14 year period were bottlenose dolphin, common dolphin and harbour porpoise.

Bottlenose dolphin (Tursiops truncatus)

The bottlenose dolphin is the UK’s best-known and often the most flamboyantcetacean. The best places to observe them in Devon and Cornwall are Torbay,Teignmouth, Bideford Bay, Falmouth and St Ives. The peak months for sightings are May, June and October.

The data reveal a significant decrease in bottlenose dolphin sightings. Sightings peaked in 1992 with a total of 340 records, but since 2000 there has been an average of only 120 sightings a year. Given the overall increase in cetacean sightings over this period (due in all likelihood to increased awarenessand reporting of cetaceans), the decline in bottlenose dolphins suggests a genuineand very worrying decline. Without comparing national and international data, it isimpossible to know whether the decline is due to the dolphins moving elsewhere ordying out. Whatever the answer, the decline is a great loss to the South West and aconcern for all those with an interest in cetacean conservation.

Common dolphin (Delphinus delphis)

The common dolphin is smaller than the bottlenose and is easily recognised by the grey and cream ‘hourglass’ pattern on its side. It is typically seen in deeper, offshore waters but sometimes ventures closer to the coast. Hotspots includeTorbay, St Austell Bay, Lizard Point and the Isles of Scilly, during the winter months.

Unlike other cetacean species, the common dolphin was seen most frequently in winter, with sightings peaking from December to February. The dolphins arethought to follow sea bass as these fish gather to spawn during the winter months.From 1990 to 1999, fewer than 50 sightings of common dolphin were recorded each year. Since 2000 this has increased sharply, reaching 900 sightings in 2004.

Falmouth

St Austell

Torbay

Teignmouth

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St Ives

Land's EndIsles of Scilly

Lizard Point

Berry Head

Bideford Bay

Morte Point

St Austell Bay

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Peak months for sightings

Bottlenose dolphin

May, June andOctober

Common dolphin

December toFebruary

Harbour porpoise

July to January


While this might be partly explained by growing public awareness and recognitionof the species, it may also reflect a major shift in the common dolphin’s distribution,perhaps due to human pressures, or conversely an increase in population size.

Harbour porpoise (Phocoena phocoena)

The harbour porpoise, the UK’s smallest cetacean, is notoriously difficult to observe.Sightings of harbour porpoises were evenly distributed around the south-westcoast from 1990 to 2004, with only a few hotspots, including Morte Point and BerryHead during the winter months. Sightings occurred year-round, though were mostfrequent from July to January. Records increased steadily since the late 1990s,reaching a peak of 110 in 2003.


Cetacean strandingsRecords of dead cetaceans, where they have been subject to post-mortem examination, can be used to identify the existence of a bycatch problem in an area.

From 1990 to 2004, the Cornwall and Devon Wildlife Trusts received more than 2000 reports of dead cetaceans. Strandings occurred all round the south-westpeninsula, with slightly higher numbers in the south. Several bodies were alsopicked up at sea. Strandings were reported throughout the year, but the peak period was December to March. From 1999-2004 there was a steady increase in thefrequency of strandings, with a peak of 345 strandings in 2003. This increase waspredominantly due to winter strandings of large numbers of common dolphins and harbour porpoises. Strandings of bottlenose dolphins have also increased,especially since 2000. Changes in the abundance and distribution of the speciesmay be involved. However, it is probable that the change also reflects a genuineincrease in cetacean deaths from entanglement in fishing gear.

Almost 95% of all UK common dolphin strandings occurred in the South West. The remaining 5% were scattered around the UK and throughout the year. Tellingly, common dolphin strandings in the South West are concentrated fromDecember to March, which coincides with a fishery known to catch large numbersof cetaceans: the pelagic (open water) pair trawl fishery for bass. However commondolphins are also victim to bottom-set net fisheries prosecuted during this time. The South West is also a hotspot for harbour porpoise strandings. Of all the UK harbour porpoise strandings that were diagnosed as bycatch, 40% came from theSouth West. While porpoise strandings from around the UK show a year-round distribution, in the South West there is a strong seasonal pattern, with a peak fromDecember to March. This matches the season for a fishery that sets fixed nets onthe seabed.

As with sightings, the stranding records rely on opportunistic reporting rather than systematic survey. As such, they can only give a partial picture of life anddeath in cetacean populations off our coast. When a cetacean dies, there are several factors that influence the likelihood of its carcass becoming stranded. These include its buoyancy, the wind strength and direction, and the distance to the shore. For example, between February and March 1997, after a period of calmweather, a prolonged westerly storm washed the bodies of 629 cetaceans onto theshores of southern Brittany and Biscay. 74% of these cetaceans showed obvioussigns of bycatch. Only a very small proportion (perhaps less than 10%) of carcasses will ever make it to the coast, and not all of these will be reported.Furthermore, if a carcass has spent a long time in the sea or on the shore, it mayhave decomposed to such an extent that little information can be gleaned from it.

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Harbour porpoise

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Reducing bycatchTo date, three main approaches to reducing bycatch have been taken in Europe and the UK: pingers, fishing gear modifications and area restrictions. Pingers aredevices attached to fishing nets that make a sound to deter cetaceans. Althoughthey have successfully reduced porpoise bycatch in several fisheries, importantquestions remain about how practical and effective they are as a widespread solution, and whether they will continue to work as cetaceans get used to them.Pingers are also unpopular with fishermen, as they are expensive and require regular maintenance. EU Regulation 821/2004 makes pingers mandatory on vessels over 12 metres in length using bottom-set nets in specified areas. Despite a requirement to have fitted pingers on all relevant vessels in the SouthWest by January 2006 and the South East by January 2007, this has not beenachieved and vessels are still putting to sea without them.

Another approach is to alter the gear used, for example by changing the net type to make it more visible or less accessible to cetaceans. A dolphin exclusion grid forthe open water (pelagic) trawl vessels implicated in bycatch has been trialled in UKwaters, but with mixed success.

Finally, restrictions can be introduced to reduce fishing effort in times or places that cetaceans are vulnerable to high levels of bycatch. There are a number of ways in which fishing effort could be reduced – reduction in the time nets are left in the water (‘soak time’), shorter net lengths, closed areas and limits on days at sea. Clearly the most effective method of bycatch reduction is closure of theoffending fishery (provided that fishing effort and bycatch are not merely displacedelsewhere). If all other methods of bycatch mitigation fail, this option should beconsidered. Such fishery closures need not be permanent or long-term as long asalternative mitigation measures are ultimately introduced.

In January 2005 the UK implemented a ban on bass pair trawling within 12 nautical miles of the coast. Despite presenting evidence to the EuropeanCommission, the ban remains applicable only to UK registered vessels. As such it has limited potential to reduce the numbers of common dolphins being caughtwithin this fishery.

The measures examined here are by no means an exhaustive list of those availableto assist in the mitigation of cetacean bycatch. Other tools include management,mitigation or recovery plans, and the use of education, training, market measuresand incentive programmes to encourage conduct that will minimise bycatch. These approaches may include consultative decision-making, data collection andmonitoring. One or a combination of the approaches and techniques listed abovemight be suitable for any given fishery.

We urgently need to recognise

the importance and tremendous

diversity of dolphinspecies found

just off the South West and

provide adequate protection to

ensure that theyare still present forfuture generations

to observe anddelight in.

Margaux Dodds

Director & Co-founder,Marine Connection

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What we need to do now!The South West is one of four dolphin hotspots in theUK. It is also the undisputed hotspot for dead dolphins,primarily killed by fishing gear. If deaths from bycatchcontinue at the current levels or increase, the SouthWest could lose its cetaceans altogether. We recommendthe following urgent actions:

Dolphin ecology, behaviour and strandings

� As a matter of urgency, undertake research to identify trends in populations of harbour porpoise, common dolphin and bottlenose dolphin.

� Conduct close-up studies of how dolphins and porpoises interact with selected fisheries and, in particular, how they behave around the nets.

� Conduct in-depth recording from strandings, includinga complete record of environmental factors (i.e. wind speed and direction, tidal information etc.), which will permit us a greater understanding of variations in strandings numbers.

� A fully resourced strandings scheme is required to permit necropsies to be conducted on all cetaceans in suitable condition and to ensure all reported strandings are recorded.

Fisheries and conservation measures

� Develop new legislation to protect cetaceans. New laws must be be proactive, flexible and swift in implementation, to cope with protection of a highly mobile species living in a complex ecosystem.

� Report on the distribution of fishing effort, number of vessels (both under and over 12 metres in length), types of nets used, length of net, soak times and other key parameters, so that specific fisheries may be linked with bycatch incidences and targeted mitigation measures applied.

� Introduce a monitoring programme to assess the efficacy of bycatch mitigation measures, in order that changes can be made as required.

� Produce detailed plans for the effective introduction, implementation, monitoring and enforcement of the pinger requirements in UK fisheries. This should include monitoring of population distribution to assess whether there is any displacement of groups due to pinger deployment.

� Either extend the requirement for mandatory use of pingers to all UK vessels in the fisheries listed in Annex I of EC Regulation 812/2004 (including vessels under 12 metres in length), or introduce alternative mitigation measures including restrictions on the use of gill/tangle nets to achieve protection of vulnerable inshore populations of cetaceans and to prevent effort shifting to the under 12 metre sector.

� Conduct compulsory observation of vessels that deploy pingers, to ensure their correct and effective use, and thorough monitoring of their impacts.

� Extend bycatch monitoring studies to include vessels under 12 metres in fisheries and areas listed in Annex 1 of the Regulation.

� Increase research and development of alternative bycatch mitigation measures and more sustainable fishing methods.

� Give power to the inshore fishery management bodies to close fisheries that are known to have a bycatch of cetaceans, turtles, seabirds and/or seals, until a suitable, working mitigation device and/or measure has been identified.

� Introduce an effective licensing system for inshore fisheries that gives the inshore fishery management bodies the power to attach conditions to fishing licences when issued and change them as necessary.

� Require all new developments in aquaculture, new fishery projects or practices, significant changes in gear design and new areas of exploitation to be subject to Environmental Impact Assessment.

What to do if you find a dolphinCetacean sightings

Report all sightings to Seaquest by going to:For Cornwall: 01872 273939

www.cornwallwildlifetrust.org.uk/nature/marine/record.htm

For Devon: 01392 279244

email [email protected]

Live cetacean strandings

For live marine strandings please contact:British Divers Marine Life Rescue 01825 765546

RSPCA on 0870 55 55 999

Dead cetacean strandings

For strandings of dead animals in CornwallStranding hotline 0845 201 2626

For strandings of dead animals in DevonDevon Wildlife Trust 01392 279244

Volunteers recording harbour porpoise stranding

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Acknowledgements

This report was made possible by the efforts of the countless individuals and organisations that have gathered cetaceansightings and strandings data in the South West and around the UK. In particular we would like to thank the Natural History

Museum, HM Coastguard, Cornwall Wildlife Trust and its Marine Strandings Network, Ray Dennis (Seaquest Southwest volunteer database coordinator for Cornwall), Brixham Seawatch, Devon Wildlife Trust, Isles of Scilly Wildlife Trust,

Sea Watch Foundation, Institute of Zoology and the National Marine Aquarium.

We also wish to acknowledge the Meteorological Office, Exeter for providing data on wind strength and direction for use in the presented analyses and all of the un-named volunteers whose time and dedication is invaluable to data collation

on strandings.

References

Jepson, P.D., Sabin, R.C., Spurrier, C.J.H., Chimonides P. D. J., Deaville, R., Perkins, M., Cunningham, A.A., Reid, R.J.,Patterson, I.A.P., Foster, G., Barley, J., Penrose, R., Law, R.J. (2005) Trends in Cetacean Strandings around the UK Coastlineand Cetacean and Marine Turtle Post-Mortem Investigations, 2000 to 2004 inclusive (Contract CRO 238) Report No. ECM

516T/05. NHM Consulting, London.

About us

Marine ConnectionThe Marine Connection is a UK charity committed to the conservation and welfare of dolphins, whales and porpoises. Through campaigns and projects in the UK and worldwide the charity is actively helping to safeguard the future of thespecies and challenge threats to their welfare – both in the wild and in captivity. Public awareness on the importance of

protecting these marine mammals and their natural environment is also vital. The Marine Connection achieves this through a mix of campaigning, education and research – encouraging the general public to be actively involved in the protection and

conservation of these magnificent marine mammals.

For further information go to www.marineconnection.org

Marine Connection Registered Charity No. 1062222

The Wildlife TrustsThere are 47 local Wildlife Trusts across the whole of the UK, the Isle of Man and Alderney. We are working for an

environment rich in wildlife for everyone.

With 670,000 members, we are the largest UK voluntary organisation dedicated to conserving the full range of the UK’s habitats and species, whether they be in the countryside, in cities or at sea. 108,000 of our members belong to our junior

branch, Wildlife Watch.

We manage 2,200 nature reserves covering more than 80,000 hectares; we stand up for wildlife; we inspire people about thenatural world and we foster sustainable living.

All 47 Wildlife Trusts are members of the Royal Society of Wildlife Trusts (RSWT) which also operates a separate grants unit administering major funds on behalf of the Big Lottery Fund and the Landfill Communities Fund. For more information

on the grants unit visit www.rswt.org.

For more information visit www.wildlifetrusts.org

The Wildlife Trusts Registered Charity No. 207238

Front cover common dolphin photograph: Caroline Weir Design: Landmark Design, Bristol Printed on chlorine free paper © 2007

I would like this and all future donations/subscriptions to Marine Connection, made since 6th April 2000, to be a Gift Aid donation.

Thank you

Lissa Goodwin, Fisheries & Policy Officer, Marine Connection, PO BOX 2404, London, W2 3WG,Tel: 0207 499 9196, Fax: 0207 409 2133, www.marineconnection.org

Joan Edwards, Head of Marine Policy, The Wildlife Trusts, The Kiln, Waterside, Mather Road, Newark, NG24 1WTTel: 01636 677711, Fax: 01636 670001, www.wildlifetrusts.org

How you can helpEvery donation, big or small, makes a difference. Please help us today by making a donation to help prevent needless

cetacean deaths. All funds will be used by both Marine Connection and Devon and Cornwall Wildlife Trusts. Please return to Marine Connection, PO BOX 2404, London, W2 3WG

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the south west dolphin report 2007

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