The status of grey seals (Halichoerus grypus) at Lundy, 2008-2009
Hiby, A.R. & Lovell, P. 1990. Computer-aided matching of natural markings: A prototype system for grey seals. Report to the International Whaling Commission (Special Issue 12): 57-61
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- 8. Recommendations: Management Plan
- 7. Anticipate and address imminent or potential seal impacts
- 7. Imminent or potential impacts
- 8. Managing impacts and potential impacts
- TV/media and seals
- Seal Research
- Sharing the seals with the public
- Contact details
Hiby, A.R. & Lovell, P. 1990. Computer-aided matching of natural markings: A prototype system for grey seals. Report to the International Whaling Commission (Special Issue 12): 57-61.Hiby, A.R. 1997. Abundance estimates for grey seals in summer based on photo-identification data. Sea Mammal Research Unit (NERC) Report to the Ministry for Agriculture, Fisheries and Food (MAFF). Contract MF0707: 17pp. Hook, O. 1963-64. Grey Seals (Halichoerus grypus) at Lundy. Annual Report of the Lundy Field Society, 16, pp.24-25. Johnson, A.L. 1956. Seal Migration. Nature in Wales, vol.2, no.2, summer 1956: 267-270. Johnson, A.L. 1957. Seal Marking in 1956. Nature in Wales, vol.3, no.1, spring 1957: 377-381. Johnson, A.L. 1959. Seal Marking, 1958. Nature in Wales, vol.5, no.1, spring 1959: 717-724. Johnson, A.L. 1961. Seal Ringing in West Wales during 1960. Nature in Wales, vol.7, no.3, autumn 1961: 83-84. Johnson, A.L. 1962. Seal Ringing in West Wales during 1961. Nature in Wales, vol.8, no.2, winter 1962: 53-55. Johnson, A.L. 1968. Grey Seal Behaviour. Nature in Wales, vol.11, no.1, March 1968: 12-14. Johnson, A.L. 1972. Seal Markings. Nature in Wales, vol.13, no.2, September 1972: 66-80. Kiely, O., Lidgard, D., McKibben, M., Connolly, N. & Baines, M. (2000). Grey Seals: Status and Monitoring in the Irish and Celtic Seas. Maritime Ireland/Wales INTERREG Report No.3. Coastal Resources Centre, National University of Ireland, Cork. 76pp. Lockley, R.M. 1958. Seal marking, 1957. Nature in Wales, vol.4, no.1, spring 1958: 537-543. Loyd, L.R.W. 1925. Lundy; its history and natural history. London. Mills, M.T. 1968. The Caves of Lundy. Annual Report of the Lundy Field Society, 19, pp.10-30. Prime, J.H. 1985. The Current Status of the Grey Seal Halichoerus grypus in Cornwall, England. Biol. Conserv. 33: 81-87. Sea Mammal Research Unit. 1994. Estimating grey seal numbers using photo-identification. Report of the Sea Mammal Research Unit, Natural Environment Research Council: 28-29. Smub.st-and.ac.uk/CurrentResearch.htm/SCOS2007/SCOS_2007_FINAL_ADVICE_1.pdf Steven, G.A. 1936. Seals (Halichoerus grypus) of Cornwall Coasts. J. Mar. Biol. Assn. U.K. 15: 493-506. Summers, C.F. 1974. The grey seal (Halichoerus grypus) in Cornwall and the Isles of Scilly. Biol. Conserv. 6: 285-291. Westcott, S.M. 2002. The distribution of Grey Seals (Halichoerus grypus) and census of pup production in North Wales, 2001. CCW Contract Science Report No.499: 140pp.Westcott, S.M. & Stringell, T.B. 2003. Grey seal pup production for North Wales, 2002. Bangor, CCW Marine Monitoring Report No: 13. 80pp. Westcott, S.M. & Stringell, T.S. 2004. Grey seal distribution and abundance in North Wales, 2002-2003. Bangor, CCW Marine Monitoring Report No.13: 80pp. Westcott, S.M & Rappel, I. 2005. Isles of Scilly Grey Seal (Halichoerus grypus) breeding season: sites used for pup production, timing and number of pups born, the identity of adults present and observations of disturbance, 15 August to 26 September, 2005. Report to Natural England (Truro) & Isles of Scilly Wildlife Trust. Westcott, S.M. 2007. A baseline study of year-round grey seal use of Boscastle coast sites on the north coast of Cornwall. Report to Natural England. 36pp. Westcott, S.M. 2008. Procedural guidelines for studying grey seals in southwest England, 2006. Natural England Research Report NERR017. 100pp. Willcox, N. 1986. A review of Grey Seal (Halichoerus grypus) pupping on Lundy, and some new observations. Annual Report of the Lundy Field Society, 37, pp.32-34. Willcox, N. 1987. Grey Seal Pupping on Lundy in 1987. Annual Report of the Lundy Field Society, 38, p.47. 8. Recommendations: Management Plan(see also Methods, 2.6) This management plan is intended to protect the seals using Lundy and the waters of the Marine Nature Reserve at favourable conservation status.If the management plan is to be successful, knowledge of the status of the seals and any pressures bearing upon them must be kept up to date. Trends and any new pressures need to be recognised. Managers are then in a position to exercise judgement and make informed decisions. The effort required to provide this data need be costly neither in time nor, if conducted under the auspices of the Warden, need it add to the current financial burden. Recommendations 1. Research into Lundy seals should be conducted from Lundy 2. Twice every month, make a count of seals using Lundy sites (both ashore and in the sea). 3. Carry out a pup production census every 5 years. 4. Monitor (and respond to) seal-human interactions. 5. How to capture injured, sick or moribund seals, or seals entangled in nets. 6. Prevent disturbance of seals from boat-based approaches 7. Anticipate and address imminent or potential seal impactsElaboration of recommendations1. Research into Lundy seals should be conducted from Lundy Research into grey seals using the sites, and especially the sea caves, of SW Britain has historically been (Prime, 1985) and will always be easily disrupted by surf action on to these sites, in turn generated primarily by wind direction and speed. The timing of the ferry and helicopter services to Lundy inhibited the possibility of taking advantage of the best sea conditions during this survey, especially on the west coast. With the research effort based on Lundy, use could be made of the best available sea conditions. 2. Twice every month, make a count of seals using Lundy sites. This must be a boat-based survey. Accurate counts cannot be made from the cliff tops. One circumnavigation of the Island should be made within 90 minutes of low water on a spring tide (ideally), counting seals using beaches, skerries and the adjacent waters. Cave counts should be made, where sea conditions permit, at Tibbett’s, Puffin Gully. Virgin Springs, NW Seal Hole, Aztec, Jenny’s and Seal’s Hole. The entire circumnavigation should not take more than three hours. At all sites, counts should differentiate between males, females, yearlings, pups and ‘unidentified’. Although no harbour seal was seen during this survey, remain alert to the possibility that they may be present (although probably not in a sea cave). Because there are some accomplished kayakers on the Island, if trained, they could contribute to this effort and thereby reduce the carbon footprint, fuel costs and the amount of boat time needed. However, such ‘auxiliary’ assistants should be discouraged from entering sea caves. Also, be aware that kayakers need to remain farther from seal haul-out sites than powered vessels because they are much more likely to cause disturbance to the seals. All results should be entered into a site-based database on the day of the survey. 3. Carry out a pup production census every 5 years. Between July and December, known seal nursery sites should be visited at intervals of not more than two weeks. In the remaining months, pups may be discovered upon occasion: expect the unexpected. Visits at high water will ensure that the search for pups will take least time, although disturbance of adults is certain to occur, while pups submerged in the water may avoid detection. Visits at low water will add much more time to survey work, may result in some pups being missed but may cause less disturbance than during high water visits. Surveyors are more likely to secure ID images during low water visits. Ideally, visit beach sites at high water. Visit cave sites at low water. The number of pups present should be recorded and, if circumstances permit, ID images of any adult seals present should be captured and entered into the island seal photo-database and shared with any national or regional scheme. 4. Monitor seal-human interactions Managers will need to decide whether there is sufficient protection for sites used by grey seals on Lundy, in the context of leisure and commercial activities at or adjacent to those sites? This will inform decisions regarding any advice to be given to divers, kayakers, boat users and any other people who might come into contact with seals.Kayakers, in particular, cause more disturbance to seals at a greater distance not only than boats but also jet skis. Although this may appear counter-intuitive, seals associate people with noise and have become – to some extent – habituated to noisy people on the sea. They have not yet become habituated to quiet people on the sea. Anecdotal accounts suggest some seals are interacting with ever-greater confidence with divers. To date, very few accounts exist that describe seals attacking people, but it should be clearly understood by all that a seal moving at speed, in collision with a human, can cause severe damage, for example, to a ribcage, which can result in the lungs being punctured. Divers need to be cautioned with regard to their interactions with seals. Anecdotal reports have been made of divers placing a hand in the mouth of a seal. They should be advised not to touch seals Coasteering may grow in popularity. If so, currently remote and almost undisturbed sites where the seals haul-out will become accessible. How can the seal sites be protected? Visiting boats anchoring in Lundy waters should be made aware of sensitive sites and asked to respect their privacy. 5. Capturing injured, sick, moribund or entangled seals. Should a seal be ‘rescued’ when found in distress, or should ‘Nature’ be allowed to take its course? A coastal manager would have to construct an ethical viewpoint on the issue. So-called seal ‘sanctuaries’ do exist to receive seals (nearly always seals in the first year of life). Ethical issues about how seals are treated while in such places include: Under what conditions are seals kept? Is it appropriate to put captive seals on show to the public, especially when people are permitted to walk their dogs close to where the seals are confined, thereby making possible the aerosol exchange of infection. Do seals become habituated to people while on display? What is the fate of seals post-release? Insist that the seal be released at the point where it was found. Generally, adult seals are difficult to capture. Although they appear rotund – plump – even yearling seals are muscular and strong. Although luck (being in the right place at the right time with the right team and the appropriate equipment) will play the major part in any potential capture, the ideal scenario would see the netted seal hauled out along the high water mark of a beach. Ideally, a rescue team of 4 is recommended, including someone used to handling animals – the shepherd? The idea would be to entrap the seal in a heavy, small mesh net, the perimeter of which should be as heavy as can be contrived. The dimensions of the entrance perimeter of the net should be 12’ x 5’. The mesh should be about two inches. There should be two people on either wing of the net entrance, holding it by means of ‘handles’ that can be gripped easily during the probably confused and stressful period of capture. The likelihood is that any capture will be untidy. Always, the seal should be approached with stealth. If natural cover does not exist, then the ‘rescue team’ should aim to approach from the edge of the sea, moving fast in order to win the initiative. Beware the bite of the seal, as they have bacterial flora around their teeth dangerous to humans. In the event of a bite, doxycyclin must be administered. Be aware of the approximate position of the carotid artery of the seal. During capture, entangle the seal. Subdue the seal by sitting astride it, knees positioned just behind the fore flippers. The (netted) head of the seal should be pinioned to the ground by the strongest member of the team. He should wear bite-proof gauntlets. Mindful of the position of the carotid artery, the netting can then be cut away. Inevitably, the seal will respond violently, bucking, snarling, snapping and shaking its head. The best way of dealing with this is to strike swift and true with the knife – be cruel to be kind, otherwise the event will become protracted and even more stressful for the seal. When adult seals fight, they are capable of tearing cooking apple sized chunks of blubber out of one another. The small wound administered during liberation efforts should be seen in that context. A very sharp knife should be used to cut through the netting – which is generally monofilament plastic, but may be heavier. The extreme sharpness of the knife is critical. SMRU use a Stanley knife (Callan Duck, pers.comm., 2009) 6. Disturbance of seals from boat-based approaches Over the past decade, there has been the development of ‘swims with seals’ operations. Of the concerns outlined in this section, these offer potentially the least cause for concern – so long as the seals with which the people swim are in the sea at the outset. However, covert surveillance of such schemes (necessary because people behave differently when knowing themselves observed) has shown that seals are sometimes initially scared into the sea, as in the Isles of Scilly (Westcott, 2005). To date, it remains to be tested whether the actions leading to the disturbance events are deliberate or simply the behaviour of people lacking sensibility. The latter is manageable. There has been the development and growth of eco-tourism ventures in the region, especially maritime eco-tourism, where people are taken on boat trips to see the seals. Such ventures are often advertised as trips to ‘Seal Island’. Until the turn of the century, trips were made mainly in converted fishing boats and traditionally built single-hulled motor cruisers. However, in recent times there has been a rapid development of marine eco-tourism enterprises using high performance rigid-hulled inflatable boats (RIB’s), usually using pairs of outboard motors. The current stage of the evolution has seen the proliferation of jet boats – in effect, highly seaworthy vessels, based on the RIB design but larger and with a substantial cabin, especially in the Isles of Scilly. RIB’s and jet boats are eminently seaworthy, high performance boats capable of making closest approach to sites where seals are assembled. In recent times, that capacity has been greatly enhanced by Geographical Positioning System-based navigational aids. The effect of their use has been to remove another layer of the protection that remoteness once conferred upon sites used by seals. Hitherto, these boats have not entered caves on Lundy used by seals, although it should be noted that similar boats have entered seal caves on the coast of southwest Wales. However, no cave on Lundy is currently accessible to such an approach. The principal dilemma facing the seals when being visited by people with what is simply a healthy curiosity and even a fondness for them is that their haul-out sites, even sometimes their nursery sites, are well known, having apparently changed little over the centuries. They form one of that small community of what are currently being described as ‘charismatic’ marine animals (cetaceans, sharks, turtles, sunfish and grey seals) that people hope to see when taking a wildlife cruise off the southwest coasts. Communications being what they are (and there is a sightings scheme called Seaquest Southwest run by the region’s wildlife trusts that is accessible on the web) cetaceans, sharks, turtles and sunfish may become easier to locate but they remain mobile. Uniquely among these animals, the seals come to land. Consequently, they are animals most vulnerable to disturbance by activity around the sites they use (as well as by people trying to study or rescue them). Indeed, it has been shown that they can be subject to daily disturbance at such sites in the summer months. This leads to behavioural change as well as causing them to enter the sea sooner than would have been the case, had they been left undisturbed (Westcott, 2000; Westcott & Stringell, 2005). Therefore, seal sites are infinitely more susceptible to chronic disturbance than are ‘sites’ used by those species that do not come to land. The ‘tripwire’ moment The most important aspect of this code is that everyone must recognise the ‘tripwire’ moment, the point at which a relaxed seal becomes so alert in response to an approach by people that it is likely to enter the sea if the approach continues. Even while resting, seals occasionally or often stir to scan the area about them. At the same time, if undisturbed, they may scratch, stretch or shift their position in order to get a little more comfortable. However, once the seal lifts its head and stares at you and clearly changes both posture and demeanour, approach no closer. This is the tripwire moment. Whether you come to a standstill or begin a slow retreat, the seal will now have come to a new level of general alertness. Even if it goes back to sleep, it will continue to watch wherever you may be for a period of at least 30 minutes – more, if you remain visible. 7. Imminent or potential impactsGlobal warming and its effect, including sea temperature rise and its effects on water movement patterns, fish stock types and relative abundance as well, conceivably, on sites currently important to grey seals. Hitherto, grey seals have been little affected by the phocine distemper epizootics of 1988 and 2002 that caused the death of tens of thousands of common seals (Phoca vitulina), mainly on the shores of the North Sea Basin. However, the trend in the transfer and rapid development of epizootics in mammals indicates that, when observations of seals are being made, note should be made of signs of illness, such as discharges from the various orifices or of swellings apparent along the profiles of the pelage. In the event of another epizootic, maintain contact with and be advised by Sea Mammal Research Unit at the University of St. Andrews, Fife, Scotland. 8. Managing impacts and potential impactsTo this outsider, it is evident that seals are already well protected against close approach on Lundy. Furthermore, the culture of the visitors appears to be to cherish the Island and all that lives there. Therefore, to a large extent, management appears to be a matter of pushing against an open door. Where necessary, the code of practise is a tool that has been applied to situations where impacts resulting from human access or proximity need to be reduced. However, these have tended to be voluntary in nature. Furthermore, even were they not voluntary, there has been virtually no means of properly monitoring and enforcing the codes. It seems inevitable that many of the intrusive and disturbing impacts current and developing must be managed in the best interest of sites, species and the general atmosphere of the edge of the world places that people are, in effect, buying (or escaping) into. It seems likely that licensing of the various activities that may cause disturbance will be required. This offers coastal manager a tool whereby control can be exerted – mainly with the lightest touch, but with rigour if necessary. Under such a regime, it is appropriate to impose pre- or re-licensing requirements designed to inform people about the sites and species they might meet and advising on how best to behave when near them. For example, they would be required to attend courses that inform the boat operator about the species involved and about how best to approach them, carrying what variety of tools (for example, good optics, species and site information materials etc.) on board to maximise the quality of experience for the passengers. The WiSe scheme (www.wisescheme.org) currently delivers just such a course, nationwide, although there are currently no specific licensing requirements pressuring operators to attend and, at this time (2006) there has been no assessment made of whether operators are implementing what they learned. TV/media and sealsPeople such as TV crews who wish to approach close to seals should be subject to scrutiny when working with seals. Personal experience as well as the experience of watching, for example, Autumnwatch on the BBC in 2008, shows that it is more important to get good footage than to avoid disturbance. Therefore, as at Skomer, permission to film seals should be sought from the Island warden or manager before taking place. Behavioural, especially time on site, requirements should be placed on such teams. Seal ResearchOn site work, especially at nursery sites, should only be undertaken by trained teams and must not be undertaken except with a permit from Natural England. There is great potential for remote monitoring of seals by volunteers, especially with regard to photo-id, abundance & distribution monitoring and disturbance, as well as in highlighting any novel developments, such as the visible signs of ill health or unusual wounds. Sharing the seals with the publicThere is the possibility of a standing exhibition on the way seals use the shores and waters of Lundy. It would consist of images and text or moving images with a commentary, giving insights into their life through the turning of the year It would give insights into their travels to visit their neighbours, based on photo-identification. They could be inter-active: question and answer options sessions or perhaps a computer game could teach people the correct way of approaching seals along with the point at which they should stop. The keynote is that they should be as local as possible, although the identity of sites should be protected, as far as that is possible (this is a dilemma requiring some discussion: do we name sites and serve as the pied piper, leading a new trail of people there, or do we describe sites without naming them?). In describing pressures that bear upon them, and our efforts to mitigate them, the fisheries with which seals come into conflict should be described. The point of view of fishermen should be represented fairly. Contact detailsLundy Warden: Nicola Saunders, Landmark Trust, Lundy, Bristol Channel, North Devon. EX39 2LY Tel. 01237.431.831. E-mail: warden@lundyisland.co.uk Sea Mammal Research Unit, Gatty Marine Laboratory, University of St.Andrews, Fife, Scotland. KY16 LB Tel. 01334.462630. http://smub.st-andrews.ac.uk/ Stephen Westcott: www.sharingthewild.com and stephenwestcote@yahoo.co.uk Mobile tel. 07817.532.393. Download 1.63 Mb. Share with your friends:
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