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The Wildlife Rescue Response The various local organisations that are involved in the wildlife aspects of a large oil spill in Shetland had for some time planned how to cope with such events. Immediately after the Braer grounded, these organisations, under the umbrella of the Wildlife Response Co-ordinating Committee (WRCC), representing the Shetland Islands Council (SIC), Sullom Voe Oil Terminal (SVT), Scottish Natural Heritage (SNH), Shetland Oil Terminal Environmental Advisory Group (SOTEAG), Royal Society for the Protection of Birds (RSPB), Scottish Society for the Prevention of Cruelty to Animals (SSPCA), and the Hillswick Wildlife Sanctuary (HWS), came together to initiate a response at the Boddam Scout hut - it having been identified as a suitable Wildlife Response Centre (WRC) 'command centre'. From there they directed all activities relating to wildlife affected by the spill; which was channelled into three categories: 1) organising teams of people to walk beaches and collect oiled birds and animals; 2) deal with live oiled birds and mammals; 3) record and store dead ones. The volunteer response from the people of Shetland to walk beaches was excellent, especially considering the appalling weather conditions during much of January. From outwith Shetland came several 'walk-in' helpers, a team of five from the Scottish Wildlife Trust and two from British Gas, while some staff members from organisations such as the RSPB came north and helped out both on beaches and in key duties at the WRC. Volunteers were organised into teams of at least two and collected all dead and any live birds and animals from accessible beaches. Where possible, beaches were checked at least twice per day. During the first few days of the spill, efforts were concentrated in the south-west Mainland, from Sandwick round to Maywick, but the northward spread of the oil up the west side, meant that by the 12th January surveys had been extended to cover the longer stretches of accessible coastline in the Burra, Scalloway, Whiteness and Weisdale areas, and westwards as far as Culswick. In total, all the accessible beaches from Leebitten (east Mainland) round Sumburgh to the Dale of Walls (west Mainland) were checked during the course of the spill, which prompted the setting up of a forward 'command post' at Holmsgarth, Lerwick from where surveys of the 'northern' coasts were co-ordinated. The total number of bird corpses recovered from beaches during January was 1542. Of these 805 (52%) were found between Sumburgh Head and Garths Ness. Only 60 corpses (3.8%) were collected from beaches along the east coast. with the remainder scattered fairly evenly along the west coast between Spiggie and Sandsound, with smaller numbers further north and west to Dale. During the first week of the spill (6-12th January) very few corpses were found away from the area between Scatness and St. Ninian's Isle, and even in this area the majority were collected from the West Voe of Sumburgh, Scatness and Quendale. In the second week (13-19th January) fewer corpses were collected close to the Braer and there was a corresponding increase in the number collected from further north on the west coast. This trend continued into the third week (20-26th January), but by the fourth week (27-31st January) very few birds were found anywhere and there was no obvious tendency for more to be found in one area than another. In any oil spill it is difficult to estimate the proportion of the actual mortality found on beach surveys, and several factors made that even harder in the case of the Braer. The almost constant storms made it difficult to search shorelines as thoroughly as could have been done in calmer weather and also made it much more difficult to catch live birds, some of which were driven inland by the wind. The weather also prevented systematic searches of the islands in Quendale Bay and further north, where birds were likely to have come ashore and died, while the exceptionally high tides at the time also compounded the problem, especially if they occurred in the middle of the day. For several days beaches were completely underwater for the 6-7 hours of daylight available for surveys, with unreachable corpses simply moving back and forth in the surf. When tides did drop, many beaches had been completely rearranged or buried in tonnes of kelp by the heavy seas. At Scatness, dead Shags had been driven deep into cracks and crevices in the rocks or buried beneath the kelp, and sometimes just parts of a bird were found. In addition, the many small boulder beaches along the south-west coast could not be checked at all due to their inaccessibility, several corpses were likely to have been scavenged by the larger gulls, and an unknown but almost certainly significant proportion will have been swept out to sea, never to be found. Live Birds and Mammals From the start of any oil spill incident, of whatever size, the WRCC had decided that every effort should be made to try and save the lives of any oiled birds and mammals found, through cleaning and rehabilitation. It was recognised that the justification for this was largely on humanitarian (and to some extent public relations) grounds and that even successful rehabilitation and release would probably involve too few individuals to offset the impact of an oil spill on the populations of species affected. It was also realised that the logistics of attempting to save live victims would be infinitely more complicated than the humane destruction on beaches that was carried out during the Esso Bernicia oil spill in 1979, the only other recent occasion when large numbers of live oiled birds have come ashore in Shetland. Live Birds The care of oiled birds was to be the responsibility of the SSPCA. A small-scale cleaning centre in Shetland, capable of handling 20-30 birds, had been planned for some time and although it has now been built, it was not operational at the time of the Braer and due to the large numbers of birds expected from the spill, the plan was to hold live birds in Shetland for as short a time as possible, give them some initial medication and then air-freight them to Edinburgh for cleaning at the SSPCA's centre at Middlebank in Fife. There was a large SSPCA presence at the Boddam WRC and with the co-operation of Shell and their charter flights south, this plan initially worked well. However, the mortality rate among Shags taken to Middlebank became worryingly high and it was apparent that they were suffering from stress from their temporary confinement at the crowded, noisy WRC and their subsequent journey south. With the northward spread of oil during the second week of January, it was anticipated that there would be a continuing, steady trickle of live birds brought in from the Burra, Scalloway, Whiteness and Weisdale areas. In view of the problems Shags were facing under the existing procedure, the decision was taken to build an emergency cleaning centre in part of a warehouse in Shell's Holmsgarth base at Lerwick. This proved very successful, with the birds taken there responding much better in the quiet isolated conditions. As things turned out, many fewer live birds than anticipated were found once the Holmsgarth centre had been built, but had there been more birds it would have proved a very effective rehabilitation centre. The question of where to release cleaned birds caused problems earlier than expected. Ideally, they should have been released in Shetland, especially resident species like Black Guillemot or those such as Shag and Eider whose populations have been declining in Shetland, By the time the first Eider at Middlebank were ready to be released however, there was still considerable pollution around the south-west Mainland and the question of whether or not bunker oil remained aboard the Braer had not been resolved. For the majority of species, it was felt that if released in Shetland they would tend to move back to the area where they had become oiled in the first place and it was therefore initially decided that Shag would be released into the Firth of Forth and everything else let go in the Moray Firth. What actually happened was much more haphazard than this, partly because of the blizzards which brought road chaos to mainland Scotland, and by the last week of January birds were being air-freighted back to Shetland for release into the sheltered, clean waters of Yell Sound. In total, 207 birds were received by the SSPCA's Middlebank cleaning centre. These comprised 116 Shag, 46 Eider, 23 Long-tailed Duck, 12 Black Guillemot, 5 Guillemot, 2 Kittiwake, 2 Great Northern Diver, and 1 Herring Gull. By the 17th January, 113 of these had died, most of these Shags. Twenty-three birds were held in the emergency cleaning centre at Holmsgarth, comprising 12 Shag, 4 Black Guillemot, 4 Eider, 2 Herring Gull and 1 Kittiwake. Of these 9 Shag, all the Black Guillemots and Eiders and the Kittiwake were successfully rehabilitated. |
Live Mammals Under WRCC plans, live oiled seals and otters were to be cared for at Jan Morgan's Hillswick Wildlife Centre, where facilities were to be developed using grants from SOTEAG and other sources, Little work had been done on this development when the Braer grounded and to make matters worse, January's storms and floods severely damaged what had been achieved. Although an estimated 500 seals, mostly greys, remained in the Sumburgh/Quendale area throughout January, few were found distressed on beaches during the first week of the spill. A large number of people from a range of different animal welfare organisations had come to Shetland to help with the care of oiled seals and this initial lull when few sick animals were found gave time for a small army of volunteers to put together temporary facilities for the animals which were eventually taken there. The great majority of the seals dealt with at the Wildlife Centre were young animals, less than a year old. On admission they showed a variety of symptoms affecting the respiratory system, the gastrointestinal tract, eyes, nose, skin, including internal bleeding and anaemia. Due to the lack of facilities at the centre at the time the animals had to be released before they were fully fit but it is a credit to those involved that 31 of the 34 animals were successfully rehabilitated. Number of live mammals taken into care |
The following account of live seals in the vicinity of the wreck is a summary of the report produced by a team of scientists from the Sea Mammal Research Unit/Aberdeen University (SMRU). "Grey Seals were often seen in the water or hauled out on Lady's and Little Holms in Quendale Bay; a maximum of 417 were recorded on the 19th January. The animals were observed and individuals scored for the presence/absence of oil on the pelt, inflammation of the eyes and secretion of blood/pus, and the presence and degree of mucus secretion from the mouth and nose and blood staining. Up to 27% of hauled out seals observed exhibited respiratory/occular symptoms associated with exposure to hydrocarbons, however this figure may be biased if animals with symptoms spend more time hauled out than unaffected animals, Comparison of these observations with seals at a haul-out site which had not been exposed to the oil confirmed that the symptoms observed in Quendale Bay were probably a result of exposure to oil. Most common seals were hauled out on the east coast, away from the most heavily contaminated areas." Live otters were regularly seen by beach survey teams who did not normally possess the expertise to assess their health. Sightings ranged from Boddam Voe, around Sumburgh Head to Scatness and Quendale Bay, up to West and East Burra, Trondra, Clift Sound, Wester Quarff, Scalloway and the Scalloway Islands to Weisdale Voe, Reawick and Tresta. Dead Birds and Mammals Under the WRCC plans all dead birds and mammals found during a large oil spill would be stored frozen until such time as a detailed examination of the sex and age structure of the mortalities could be determined for each species, as well as any other appropriate scientific investigations. All the corpses brought back by the beach teams were bagged, labelled and packed into a P.&0. freezer container at the WRC. In February, this was shipped down to Edinburgh University's Department of Veterinary Pathology where the very messy examination was undertaken, At the time of writing the resulting bird data is being analysed but it will be a lengthy process and a detailed results will not be available for some time, although some preliminary data on the Shag corpses and an analysis of the gizzard contents of these and a few other species is presented below. Dead Birds Apart from the fact that a lot of dead birds were never found, there are two problems associated with compiling the Braer casualty list. The first is that the storms during January were causing a high mortality of seabirds quite apart from the oil, and some of these storm victims may have become oiled after death by coming ashore on polluted beaches. Secondly, by the end of January small numbers of freshly oiled birds, which clearly had nothing to do with the Braer, were being found on beaches. Although the seas around Shetland are normally cleaner than in most parts of western Europe, oil pollution on a small scale does occur in winter and so a cut-off point for the Braer casualty list was fixed arbitrarily as the end of January 1993. The 'official' casualty list for January is presented below, which differs from some others as clean corpses and those unlikely to have been killed by the Braer have not been included. Number of dead and live birds found |
Grey Seal Common Seal Total |
31 3 34 |
Examining the individual species in the list, some will have been greatly under-recorded in terms of the number of birds oiled and never found. As an example, in the first few days of the spill, several thousand oiled Kittiwakes and Herring and Great Black-backed Gulls were estimated to be in the Sumburgh/Quendale area, many feeding on the dead fish and marine invertebrates washed up in Quendale Bay. A large proportion of these were judged to be too heavily oiled to have survived, but relatively few corpses of these species were found. In addition, small flocks of shoreline feeding waders such as Turnstone and Purple Sandpiper were seen to have become oiled along Garths Ness and Scatness (and probably also further north, especially along the more polluted beaches on Burra), but no corpses of these species were found. Shags dominated the mortality with Black Guillemot, Long-tailed Duck and Eider the other main diving seabirds involved, while Kittiwake was the main gull species involved. Thankfully, the very storms which caused the Braer (although causing the wreck of Kittiwakes) kept Fulmars and the pelagic Auks well out to sea, and the numbers of these species found oiled was very low. Fewer Great Northern Divers were found than had been feared and the leucistic bird that has wintered in Sand Sound for the past 12 years also survived, despite the heavy sheens which entered that area, The single Black-throated Diver picked up on Quendale beach was one of two known to have been in the area for several weeks, while the King Eider was a female found lightly oiled at Sand. Examination of all the corpses at the Edinburgh University Veterinary Field Station showed that almost all were oiled, with the majority heavily so, in particular the Shag corpses. During examination, all the Shags that were mostly intact were aged from plumage characteristics and sexed from examination of the genitals. A proportion of Shags which could not be sexed in this way were tentatively sexed from measuring the gonys depth (the depth of the bill at the widest point) - a depth of more than 10.6mm taken as being a male. The results are shown below with the numbers of birds for which sex was inferred from their gonys depth shown in brackets. |
There is a clear excess of females over males which is significant within both immature and adult groups, although the bias is greater for adults than for immatures. The ratio of first to second winter birds was not significantly different from 1:1 for either sex. As well as providing details on the age and sex structure of the casualty list the examination of the gizzard contents of many of the corpses gave information on the diet of the seabirds around the area of the spill. After birds had been aged, sexed and measured those that were no longer required but had a gizzard present were dissected to remove the gizzard and intestines. Prey remains from the gizzards were stored in 70% alcohol and subsequently identified to the lowest taxonomic group conveniently possible, with most attention given to the identification of fish otiliths *1. Most of the Shag gizzards were empty with those containing prey remains mostly fish otiliths, especially sandeel Ammodytes, with most of the other fish otiliths present rather small (3-9mm). A very high proportion of the Shags had parasitic worms in the gizzard. The proportion of Shags with prey in the gizzard declined rapidly with finding date, 375 containing sandeel otiliths on the 6-7th January, but only 7% containing sandeel otiliths after the 16th January. Black Guillemots held crab remains more often than otiliths, with most of the latter being sandeels. Eiders contained mostly bivalves, gastropods and crabs. Long-tailed Ducks had mainly empty gizzards or small quantities of algal material that may or may not have been ingested while feeding on invertebrates, while their animal prey remains consisted of bivalves, gastropods, sandeels and polychaetes, thus showing only partial overlap with Eider diet. Kittiwakes had mostly empty gizzards, but sandeels were present in 38% of those with prey. A further 10% contained plastic pellets, as did 50% of the Fulmars examined. Guillemots contained mostly fish otiliths, predominantly those of sandeels or gadids *2. The small numbers of gizzards of other species provided little clear indication of diet, but it was surprising that Great Northern Divers had only bivalve fragments and and fish otiliths on their gizzards The high frequency of sandeels in diets of Shags, Tysties Kittiwakes and Guillemots in January provides clear evidence that this fish is available to seabirds even during winter, and appears to be the main food of Shags and Guillemots in this season in Shetland. The clear trend for stomachs of Shags to be empty if the bird was collected later after the spill may suggest that some of the later collected birds died of starvation rather than dying rapidly from the immediate effects of the oil. However, the ratio of sandeels to gadids found in the Shag gizzards did not change over time, suggesting that diets and rates of otilith loss in gizzards were not noticeably different over the month. Also the number of otiliths per gizzard with otiliths changed little, the reduction was predominantly in the proportion of Shags with any otiliths in the gizzard. * 1. A fish otilith is a small bone found in the skull whose size increases with the age of the fish. Because this bone is relatively indigestible in birds stomachs, and because there is only one bone of this type in each fish, by counting and measuring each otilith the number and size of food prey can be identified. * 2. Gadids are immature fish such as cod, etc. usually quite small, 3-10 cm long. Dead Mammals Of the 23 dead seals found on beaches during the incident, 11 were recovered with the remainder being tagged to prevent double recording. Four of the grey seals were post-mortemed by vets from the Scottish Agricultural College (SAC), three were determined to be pre-spill deaths and the fourth died from unknown causes, though it may have been oil-related. Many of the unidentified seals were badly decomposed and some of these are likely to have also been pre-spill deaths. It is impossible to put these figures into context, since there is very little previous information on the number of dead seals which normally come ashore in Shetland. Number of dead mammals found |
Adult Immature (total) First Winter Second Winter Unaged Totals |
Male 95 (15) 133 (18) 20 (2) 20 (2) 4 (2) 232 |
Female 240 (33) 221 (39) 43 (9) 28 (2) 10 (8) 471 |
Unsexed 30 34 2 0 44 108 |
Total 365 388 65 48 58 811 |
Six dead otters were found during the course of the incident, all of which were examined by an SAC vet. Of these, two were road traffic accidents (one of which was allegedly run over by a Norwegian film crew), one was oiled but was found at Brae, well outside the Braer affected area, two were lightly oiled and may have been oil related, and one was not oiled and presumably died from natural causes. |
Grey Seal Common Seal Grey/Common Seal Otter Total |
12 1 10 2 25 |
Checking beaches for wildlife. |
Collecting oiled corpses. |
Large numbers of fish were also found dead on beaches. |
Emulsified oil on beaches. |
Loch of Spiggie RSPB reserve was threatened by oil during high tides. A boom and later a sand and earth dyke were used to prevent the ingress of oil. |
Shag being cleaned of oil. |
Oiled Eider being cleaned. |
Oiled corpses being collected. |
Oiled Black Guillemot corpses awaiting examination at the University of Edinburgh. |
Examining bird corpses. |
Oiled Guillemot corpses. |
Oiled Puffin corpses. |
Oiled Guillemot being cleaned. |
Oiled Razorbill corpses. |
braer.net |
M.V. Braer grounding and oil spill Garth's Ness, Shetland, 5 Jan 1993 |
The impact of the 1993 Braer oil spill on grey seals in Shetland. Hall AJ, Watkins J, Hiby L. Sea Mammal Research Unit, NERC, High Cross, Cambridge, UK. Signs of acute respiratory distress were reported in moulting grey seals (Halichoerus grypus) hauled out on Lady's Holm, Shetland, following the Braer oil spill in January, 1993. Behavioural observations carried out between 16 January and 13 February 1993 showed that the proportion of animals exhibiting a discharge of nasal mucus was significantly higher than the proportion at a control site in the north (Papa Stour). The proportion of animals affected on Lady's Holm increased for up to one month following the spill. However, the time lag between exposure and peak response was approximately 30 days, longer than may be expected for an acute effect. The proportion of non-specific signs of respiratory distress in unexposed Shetland seals was assessed from observations made between 16 January and 25 January 1994. Symptoms similar to those seen in 1993 were also reported during this period, but the proportion of affected animals was higher in 1993. Symptoms were not observed at a grey seal moult site on the east coast of England in March 1993 and 1994. Grey seals moulting in Shetland during the time of the oil spill may have been acutely affected by exposure to hydrocarbons, but without sufficient baseline data on the occurrence of respiratory distress in grey seals it is difficult to determine the proportion attributable to other causes. From the Journal Sci Total Environ http://www.ncbi.nlm.nih.gov/pubm ed/8685704 |
Releasing rehabilitated seals from the Hillswick Wildlife Sanctuary. http://www.shetlandwildlifesanctuar y.com/The%20Braer%20Story.htm |
How does oil affect Marine Widlife? The effects of oil on marine wildlife are caused by either the physical nature of the oil (physical contamination and smothering) or by its chemical components (toxic effects and accumulation leading to tainting). The animals most at risk are seabirds, as they spend much of their time on or near bodies of water. The scale of vulnerability of seabirds depends not only on numbers present but also on the behavioural and other characteristics of the species involved. Birds that are frequently affected by oil spills include those that remain and feed in the water. However, other non-aquatic birds may suffer from any of the following effects when they scavenge on oiled carcasses along shorelines. Seabirds are severely affected by spills. The oil penetrates and opens up the structure of their plumage, reducing its insulating ability, and so making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. It also impairs birds' flight abilities, making it difficult or impossible to forage and escape from predators. The internal effects of oil on birds, while not as apparent as the external effects, are equally life-threatening. As a bird tries to clean oil from its feathers by preening or as it feeds upon a contaminated food source, it ingests or inhales oil. Depending on the type of petroleum product, its weathering stage, and its toxicity, ingestion can be sub-lethal or acute. Direct toxic effects on the gastrointestinal tract, pancreas and liver have all been documented. Ingestion of oil frequently results in injury to the gastrointestinal tract. This damage prevents the animal's digestive system from utilising food or water, causing the animal to become progressively weaker in a very short time. A similar irritation of other mucosal surfaces can lead to ulceration of eye surfaces, and the moist surfaces inside the mouth. Kidney damage is believed to occur both as a direct effect of the toxins in the oil and secondary to severe dehydration. As an oiled bird becomes more debilitated, its immune system is compromised and the bird becomes susceptible to secondary bacterial and fungal infections. The oil may also have an effect on the ability to reproduce, the number of eggs laid, the fertility of the eggs, the shell thickness and the breeding and incubating behaviour. Most birds affected by an oil spill die unless there is human intervention. Marine mammals exposed to oil spills are affected in similar ways as seabirds. Oil coats the fur of Sea otters and seals, reducing its insulation abilities and leading to body temperature fluctuations and hypothermia. Ingestion of the oil causes dehydration and impaired digestion. |
Where wildlife become impacted by oil, it is important to systematically collect and analyse data in order to enable a sound scientific assessment of the damage to populations. Population effects of oil-induced mortality on seabirds are difficult to assess and few studies have succeeded in identifying trends in population size or recruitment, following a given oil spill incident. Scientifically sound estimates of the total number of birds killed require effort-corrected beached bird surveys and drift-experiments in the immediate aftermath of a reported incident. All collected animals should be analysed to determine three variables: the species composition, the age structure of the casualties and their (most likely) breeding origin. In order to collect the required data in the immediate aftermath of a reported incident, Impact assessments should be fully integrated into the overall oil spill response. This allows the planning of the necessary scientific activities during other cleanup activities without disturbance, avoids corpses of casualties being disposed before they have been recorded and allows more general conditions (health and safety of responders, financial aspects, training, effective use of resources) to be in place. |