Document zokd0x71JnaVgY383m8meE27B

JC..;; ' "7 '.7. -Ti . n ; *4*" " S3, ^C. /&tiaL\et SEA BIRD WRECK IN THE IRISH SEA AUTUMN 1969 THE NATURAL ENVIRONMENT RESEARCH COUNCIL PUBLICATIONS SERIES C No4 1971 yffSuff! HONS 050548 SEA BIRD WRECK IN THE IRISH SEA AUTUMN 1969 1 This it;potV is about the deaths of over 12.000 sea birds, mostly guillemots, which wore washed up on (ho shoios ol the Irish Sea and its approaches in Iho auluntn ol 1969. Il describes the main features 01 Ihe incident, die investigations that woie put in hand to ascertain the causes, and the conclusions ih.it (tnutiyeri 2 Iho incident aroused public concern at the time and much speculation as to its cause. This is under standable People are growing increasingly con cerned about theii environment and the far-reaching consequences that human interference with it can have The sight ol oiled birds on our beaches is unfortunately only too common these days; but depressing though it is. at least the cause is obvious. When beachos over a considerable area become scattered with unusually large numbers of dead or dying birds of which no more than fifteen per cent an? oiled, and when the first sample to be analysed contains substantial residues of chemical substances (polychlorinated biphenyls) the biological effects of which are little known, it is right that the matter should be thoroughly investigated. 3 The Nature Conservancy acting in consultation widt the voluntary bodies (paragraph 8) reported those facts to the Hcadguarlers of the Natural Environment Research Council in the middle of October 1969. following a press statement by the Royal Society foi the Piotection of Birds. There followed an investigation involving some thirty organisations and laboratoiies working in coflabora- tion with the voluntary societies. The work was planned and the results collated at two major meet ings convened by the Secretary ol NERC m Council Headquarters, one on 24 October and the other on 11 November. 4 The outcome as is reported in what follows, is that no single lactor natural oi nrtihcial can be regarded with certainty as the mam cause of the incident. There have been similar sea-bird vyecks in the past, before pollution can have been a possible cause. Widespread evidence of malnutrition was found among the dead birds in this incident but there was no evidence of shortage of the fish on which they teed: much more knowledge of the feeding habits of guillemots is however needed before these apparently contradictory facts can bn reconciled. The effect of the malnutrition of the birds was probably compounded by natural causes including moulting, disease and gales (there were high winds during part of the period), and may have been aggravated try the toxic effects of the metallic and organic residues found in many of the dead birds. But no one oi these factors can alone be regarded as the decisive cause of the incident. 5 It is quite possible that this is the true explanation of the mystery -ie that several different factors in combination were responsible. If so, the implications are not reassuring. It opens the possibility that although pollutants in the seas around Britain may not be present in sufficient concentrations to harm wild life directly, they may yet increase the chances that a bird or other organism which is under stress from some other cause will die rather than recover. Even a small shift in the balance between life and death could have a profound effect on the balance of whole populations. 6 A full account of this enquiry and the details of the laboratory work by the many Institutions (both within and outside NtRC) which collaborated has been edited by Dr M W Holdgale who at the hme was Deputy Director (Research) of the Nature Conservancy and who also acted as general co ordinator during the incident. This account* is being made available in mimeograph to interested organisations in this and other countries which are concerned with pollution problems. Particular as pects will also be published in scientific journals by the investigators concerned. HONS 050549 1 * 7/ir Scalurd Wrnck of 1969 m the Irish Sc* A Rr/toil of ihe irM/H/tttitn i iini/ui li.'t/ wider Ihe Auspices ol fhtf NtluiAl fnvironotrni Arse.nth Count il f ihteil by Dr M W Hnhltmie ORGANISATIONS PARTICIPATING IN THE INVESTIGATION 7 1 he Natural Environment Research Council (NERC). which acted as general co-ordinator for this investigation, has as its Prime function the sciimtilic study and conservation of the natural en vironment and its resources. Research with this objective is promoted by the Council at a number of institutes and by grants to universities. That which is concerned with the investigation of the dynamics nf wildlife populations must clearly take account of the possible effect of pollutants as well as of natural coiises ns lectors influencing the stability of those populations. 8 Within NERC. the Nature Conservancy is Britain's official wildlife conservation body, but the country is fortunate in also having voluntary consalvation organisations especially concerned with buds, notably the Royal Society for the Protection of Birds (RSPB), the British Trust for Ornithology (RTO) and the Seabird Group (a specialist group sponsored by the three major ornithological socie ties).* All these contributed to the investigation. In addition, officers of the Royal Society for the Pre vention of Cruelty to Animals (RSPCA) and its Scottish counterpart. (SSPCA). members of local natural history aocietios and Trusts for Nature Consuiv.ttion, and people Irom universities as well as pnviiie individuals helped in counting the casualties on the beaches and in collecting materiel for post modern examinations. The voluntary ornithological bodies also collected the records and prepared dnmled casually lists Dr W R P Bourne of the Sunbud Group collated and edited the evidence fiom all these sources. 9 Because the incident involved fish-eating sea birds while they were at sea. suspicion was at the time understandably directed towards the marine envu onment. For that reason the Fisheries Research Lalxuatones of both the Ministry of Agriculture, Fisheries end Food (MAFF) and the Department of Apiir.ulture and Fisheries of Scotland (OAFS) were duoctly involved from the outset and played a major part in the investigations. Mr 8 B Parrish. Director of ilie OAFS Marine Laboratory, Aberdeen, co-ordin ated the collection of samples of seawater and of marine life (including the small fish on which the birds feed). 10 On the laboratory side of the study, post-mortem (xnminntions of the victims were carried out mainly by the Monks Wood Experimental Station of the Nature Conservancy and the Department of Animal Pathology of Cambridge University, and also by the MAFF Veterinary laboratories at Lastwade, the Central Veterinary Laboratory at Wtybridge. the Laboratory of the Ministry of Agriculture of Northern Ireland in Belfast, and the Wildfowl Trust Tests for the presence of viruses and bacteria ware done by the Department of Animal Pathology at Cam bridge, the Agricultural Research Council (ARC) Institute of Animal Diseases at Compton, the Medical Research Council (MRC) National Institute of Medical Research at Mill Hill, the MAFF leboretory at Lasswade and the Central Veferinary Laboratory at Weybridge. Chemical analyses were done by the Nature Conservancy at Monks Wood and at Merlewood Research Station in Lancashire, by five MAFF laboratories, by two DAFS stations, by CDE Porton and by the Laboratory of the Government Chemist: Monks Wood Experimental Station co-ordinated this work and collated the evidence from all these sources. A full list of all the organisations and laboratories involved, end the work they undertook is set out in Appendix I THE 1969 INCIDENT AND COMPARISON WITH PREVIOUS WRECKS 11 The incident began with the arrival of small numbers of sick and dying birds on the shores of Northern Irelend eerly in September 1969. In the second half of September the mortality rate in creased dramatically and many thousands of guillemots were cast up in North Wales, South-west Scotland, Northern Ireland and other areas around the Irish Sea. Strandings of smaller numbers of dead birds continued into November. Estimates, based on counts, indicate that over 12,000 dead birds came ashore. Oil pollution affected only a small proportion and where it did occur was almost ail traced to local spillages Ninety per cenr of the mortality was among adult guillemots, mostly of the race breeding in the Southern areas of the British Isles. Most of them were in heavy moult at the time. The distribution of dead birds does not suggest that all the birds died from a single cause operating at one place and time. 12 Table 1 records the counts of dead birds on various coasts. It is clear that a dramatically large number of deaths occurred only around the Irish Sea and its approaches. The smell numbers from the east and south coasts give an indication of 'normal mortality' at this time of the year and confirm that the number of deaths in the Irish Sea area was far higher than the norm. ` The Hovel Society tor the Protection of Birds, the British Trust for Ornithology end the British Ornithologists' Union MONS 050550 13 Ihc* Injures in Table 1 are subject to various errors. f-oi instance the total number of birds stranded in south-west Scotland, where the greatest number came ashoru, is derived from sample counts mode on selected sections of beach to give an estimated figure for the whole coastline. The ecr utucy of the total of 17.347 dead birds depends Imgely on the accuracy of the estimate for guillemots toimd in SW Scotland, and to a lesser extent on similai estimates elsewhere. What can be said with ci'M.imty is that mom than 12.000 dead birds prob ably came ashore round the Irish Sea in the three monthA from August to November, and the evidence ot ringed birds, provided by the BTO. supporte the view that the dead birds came mainly from colonies in the southern part of tho Irish Sea. Because some ini- likely to have sunk or drifted into the open Atlantic, the total may well have been much higher; some ornithologists estimate tho death toll as high a*. bOOOO 100.000 birds. 14 Confronted with an incident of this kind, it is natural to search for precedents. Two species often involved in large scale wrecks in the British Isles, and indeed in (he North Atlantic generalfy, are Leach's petrel {Ocaanodroma leucorrhoa) and the little auk (Plautus alia). At least forty little euk wrecks have been recorded in the British Isles. They ere often associated with storms, and a study of one of the most recent indicated that they result from a massed movement of birds from their normal Arctic habitat into more southerly waters deficient in food, where they become weakened and liable to be blown ashore by gales. The larger auks {puffin, guillemot and razorbill) ere wrecked far lets often than the little auk. and generally in smaller numbers. It is not unusual for a few tens or even hundreds to be cast ashore, but massed deaths like those of guillemots in the 1969 wreck are rare. 16 Previously recorded wrecks of large auks in the British Isles are summarised in Tabie 2 (page 4) TABLE 1 Estimates and counts of daad birds on tho beeches (Most of these figures' are based on the Beached Bird Survey organised by the RSPB and the Seabird Group) SPICKS (AST* SCOT UNO (AST ENG LAND SOUTH WALES NW ENGLAND ENGLAND WEST SCOT LAND ISLE OF MAN INELANO TOTAL WINGS POST COL MONLECTED TIM Ob..r*r 10 24 23 67 22 46 6 21 222 -- - Divers and Giebes 1 4- 13 - -- 9- - Manx Shearwater - - - 34 - -- 7- - Fulmar 5 1- - 1 - -- 7- 1 G.innet 633 75 33 5 35 -- Cotmorant, Shag 2 1 1 46 32- 19 1 1 Ducks 13 3 - 3- 31 - 23 - 1 Waders 2 5- 23 1 1- 14 - - C.BB Gull 6 3- - 6 - 2- 17 - - Heiring Gull 27 8 2 16 18 66 5 88 1 1 RH Gull Kittiwako Other Gulls Terns R.i/orbill 352 44 - - 1 19 - 1 57 1 24 13 2 25 - 2 1 31 11 - 1 1 9- 1 3 1 1- 1 - -- 6- - 9 4 1 36 36 14 2 41 142 15 8 Guillemot 17 20 5 2019 B98 11,816 320 1794 16.889 528 112 Othoi or unidentified Auks 2 1-- 30 1 3 _ 1 38 -- TOTALS 102b Be 17 212*1 990 11,9901 341 19501 17,3471 949 129 `I in t mundane* ol regions see map: page 8 * Guillemot figures partly based on estimates Based on counts. 3 HONS 050551 None of these wrecks closely parallels the events of 1969. The incident in 1859 was somewhat similar in that it occurred off south-west Scotland in late summer, just after the birds had left their breeding grounds. However, it is said to have kilted mainly razorbills even though guillemots were abundant in the area. The tola! death roll was probably less than in 1969 although the auk populations are believed to have been many times larger a century ago. The wreck in 1889 is very poorly documented but also seems to have happened just after the breeding season and may have coincided with severe gales. The symptoms of the birds that died in the highly local wreck in the Solway in 1907 seem reminiscent of those in 1969, end the timing is Similar as it was in 1941. 16 It seems clear, therefore, that there have pre viously been wrecks of the larger auks in the period August-September. These have often coincided TABLE 2 Wrecks of tha larger auks in British waters oat i PtACt MAIN SPECIES OTHER SPECIES MORTALITY OTHER OBSERVATIONS 1856 (11 My) North Norfolk guillemot razorbill. puffin, guile 'large numbers' (240 counted in 2 miles) Severe north-westerly gales in early May. Remarkable as no auks breed in the vicinity. 1868 North Norfolk guillemot (September) puffin. razorbill, scoter, divers `large numbers' 1B58 (date Cornwall uncertain) puffin not stated 'large numbers' 1859 (about August) Western Scotland (Clyde to Belfast tough) razorbill (90%) guillemot, puffin, gulls 'hundreds, even thousands' Severe storms noted elsewhere at the same period. 1867 Outer Hebrides all auks *a great number' Bad weather during breeding season caused many to die on the ledges. 1872 (early in ysnr) England and Scotland razorbill none (noted et lime) 'Many' ca. 1889 (late summer) Ailsa Craig larger auks 'massive' (many thousands?) Deeths after leaving breeding places said to have greatly reduced population. 1895 (AugustSeptember) Loch Leven (Argyll) guillemot, razorbill not stated Some birds blown inland by gales. 1907 (AuguslSoptember Solway Firth guillemot razorbill heavy and prolonged Young and old guillemots: some razorbills. Came close inshore or stranded in helpless condition. In good plumage but emaciated with empty stomachs. 1911-1913 Ailsa Craig, guillemot. Rathlin Island. razorbill St. Kilda puffin, kittiwake progressive decline in breeding populations Gannets on Ailsa Craig unaffected as were seabirds generally in Shetland. Orkney and east coast. 1941 Firth of Clyde guillemot (September) not recorded about 2,000 HONS 050552 wm stormy weather. which may hava been the primary cause in some cases but in others may have driven ashore or despatched birds that had already been weakened by other (actors such as disease or malnutrition. The largai auks, both adults and younfl. are flightless On moult or with growing feathers) and at sen during this period. THE INVESTIGATION 17 1 hr- first step was to review what was happening at the time in the natural environment: the weather, thr sen currents, the state of marine life, and especially lira abundance of the fish on which the buds feed- both at the time of the incident and in the months leading up to it. If the deaths were due to purely natural causes, there ought to be evidence of something else amiss in the Irish Soa during this period 18 Although the main stranding of the dead and dying birds coincided with the stormy weather in the last weeks ol September, over a hundred came shore before the onset of the storms. This suggests that many birds ware already weak or dying before thn gales began. The storms may have increased the stress on the birds and raised the mortality, besides bringing many more victims to the beach, but they appeal to have been a secondary rather than a prime or the sola causa of the deaths. A contributory factor could have bean the moulting of the birds as already indicated (paragraph 16). 19 An examination of the abundance and distri bution of lha fish species on which ths birds normally depend for food was undertaken, and a search made for evidence of blooms' of phytoplankton or toxic algae which might be poisonous to guillemots. No evidence of a food shortage or of an abnormal abundance of toxic algae was found. But we know too little of the detailed feeding behaviour of the birds, or of the particular combinations of weather and ssa conditions which affect the birds' feeding success, for these negative results to be concfusive. 20 The eomHtioit of the blrde--Bird wrecks in the past have been attributed to disease and soma ol tha features of the 1969 incident suggested that an vpidamic of some kind might hava occurred. Those features included the apparent sickness of the buds obsorved before the mein peek of deaths, the lack of precise conformity between the pattern of donths end the pattern of storms, and the way in which (he number of deaths built up and then died away. Tissues from some 46 guillemots and one ta/orbill. common gull, herring gull and kittiwaka that (find in the disaster, and from one apparently hoalthy guillemot that was shot, were therefore submitted to microbiological examination, but tests for pathogenic viruses and bacteria proved negative in all cases. Disease cannot however, be wholly eliminated as a causa of the disaster because of the lime that unavoidably elapsed between the deaths ol many of the birds and their arrival at tha laboratories, but the tests provide no evidence lor this as a cause of death. 21 Post mortem examinations were carried out on 129 seabirds (112 baing guillemots) and one mute swan; and as healthy specimens ware needed for comparison, 18 guillemots were shot lata in the autumn. All the laboratories agreed that the auks that died in the incident were in a poor state of nutrition. Their fore guts and muscular stomachs ware empty, in contrast to those of tha shot birds which contained either fish or the residues of a recent meal. Almost ell the bodies felt very light and thin, with prominent breastbones; in a sample of sixty-one the average weight of the birds was between half and two thirds that of apparently healthy birds. The deed birds lacked subcutaneous fat. and most had wasted breest and thigh muscles. More unusual and perhaps more significant wart changes found in the livers and kidneys of the birds that died in the incidsnt. All the livers were dark end full of blood, and detailed microscopic investigation of five of them showed unusuel changes in the tissues. The kidneys of most of the casualties appeared swollen and unusually pale in colour, and superficially resembled those of Bengalese finches killed by PCB poisoning in an experiment at Monks Wood. 22 The different laboratories did not entirely agree in the interpretation they put upon their post mortem findings, although much of tha divergence of view was probably due to the small number of samples that it was practicable to examine in many cases, tha partly-decomposed state of much of tha material, and tha paucity of knowledge of the normal internal condition of healthy birds. The Monks Wood and Cambridge laboratories, which between them exam ined the great majority of the specimens, noted that pathological changes were present in the majority of the birds examined, but that there was no evidence of specific disease or of oil poisoning. They also concluded that in no case could death ba attributed directly to starvation. However, e poor to very poor state of nutrition was characteristic of all their sample of birds, and they concluded that they had not fad adequately for some time and had bean drawing heavily upon their body reserves. 23 The specialists at the Central Veterinary Labora tories, who ware able to carry out histological examinations of material from a limited number of birds, reported that there was a consistent pattern in the unusual histological changes in the liver. It was considered that the most likely cause of the lesions in the liver wes a poison of some kind. This 5 HONS 050553 toxin could have been absorbed from the intestines and carried by the blood to the liver and kidneys, where it may have had a specific toxic effect on the veins and tissues around them. The hepatic leaion wm thought to be strikino and unusual, end it may be significant that similar symptoms have been observed in chicks fed with PCB in an experiment. 24 The workers at the Compton laboratory, in contrast, noted no macroscopic lesions in any of their birds, end reported that there were no eigne of obvioua disease. They concluded that the deaths were due to starvation. 25 The programme of analysis--A large part of the effort of the laboratories who collaborated in investigating the 1969 seabird wreck was devoted to chemical analyses. Semples of sea-water, end marine life of all kinds as wall as the tissues of the seabirds thamseivas wart analysed for toxic sub stances. The reader who is interested in the results of these analyses will find them in Appendices II to IX at the and of this report, and only a short account of the work is given below. A complete account of the laboratory methods and results it provided in the full report and supplement already referred to in the Introduction. Caution is needed in interpreting the data as the number of specimens it was possible to examine was small in relation to the total seabird mortality and indeed smeller than is statistically desirable. 26 Metallic residues--Traces of many metallic elements art naturally present in animal tissues but are toxic in excess. Analyses for four metals in sea water end marine life ere given in Appendix II. A comparison with the figures shown there for samples from other areas indicate that the Irish Sea end its marine life do not appear to carry higher concentra tions of these metals (hen the other coastal regions of Britain which have so far been examined. Appendix III shows the concentrations of various meteis found in the Uvera and kidneys of guillemots. Some of (he deed birds showed relatively high levels of particular meteis and in some cases the highest concentrations were above the level at which poison ing may have occurred. In general the range in the casualties of the incident and in healthy birds shot for comparison evsrlap. 27 These analyses were of course undertaken before the presence of mercury residues in imported tinned tune fish attracted publicity in the autumn of 1970. The levels of mercury, lead, cadmium end arsenic in the livers and kidneys of some birds ore unquestionably high, although they may have been elevated by shrinkage of the organs after death and thay should not bs taken as precise indicators of the situation in the general seabird population. Nevertheless such observations of high tissue con6 centrations in predators should alert us to the possibility of hezerdous levels of these potentially toxic substances in British inshore waters. All these meteis ere in feci natural components of tee water in minute amounts, end more research is needed to indicats whether these background levels have been raised to significant amounts by pollution. 28 Orgsnls Insecticides end Kls-Somi of the first analyses of deed birds carried out at Monks Wood Experimental Station confirmed the presence of residues of the organochlorine pesticides DOE (a breakdown product of DDT) and duAdrin and suggested also that unusually high concentrations of polychlorinated biphenyls (PCBs) wars present in the livers. An extensive programme of enelyses for the organochlorines end PCBs in sea-water, marine life and see birds was therefore carried out. The results are given in Appendices IV to IX. 29 The organochlorine pesticides may have con siderable effects on living tissues, but their 'back ground level' in the environment is normally well below that likely to harm wildlife. However, their solubility in fat causes them to be accumulated in the fatty tissues of animals. Aquatic plants and small marine organisms contain only minute amounts of these compounds, but their concentrations increase as they pass up the food chain to predators such as fish or birds. Ssabirds as long-lived animals, coming at the end of such a food chain, can acquire large quantities of organochlorines even when these ere present in the environment el very low concentra tions. When such birds come under stress, or suffer from shortage of food, they draw on their reserves of body fat and so mobilise accumulated residues, which pass into the bloodstream and ao reach, and may affect, important organs. Birds containing significant amounts of organochlorint pesticides, even when not otherwise stressed ere known to suffer disturbances of their calcium carbonate metabolism and behaviour, lay thin-shdtal sggs, and have a lower breeding success then normal. 30 PCBs are not pesticides. In this country they have e wide variety of usss in industry. They srs. however, organic compounds containing chlorine, have ths asms properties of persistence, fat solubility and biological activity as DDT and dieldrin, and can be concentrated in food chains. Their effects on birds are less well known than those of orgenochlorine pesticides, but preliminary experiments indicate that they can have similar effects although they appear to be somewhat leas toxic to birds than DDT. 31 Tha concentrations of PCBs and organo- chlorin# pesticide residues in ses water, invertebrate marine life end fish from the general area of the bird-kill were not unusually high and were generally within the range observed previously in this *r*a and elsewhere. The concentrations of DDT and MONS 050554 ilirldriM in fish wcm* mostly lower than those of I'Offs Hu: results arc set out In Appendices IV and V 32 The quantities and significance of organo- < Mount: pesticide residues in British wild birds have been studied lor nearly ten years by a number of lahointoiins and especially at the Nature Con* M'lvancy's Monks Wood Expeomental Station, so dial ttieie is a pood basis for comparison. Particular attention has boon paid to the concentrations found in the livets and eggs of buds of prey and freshwater lish e.itiMS such as the heron. Since 1966. most spec'linens have .been tested for PCBs as well as 11p| ontiinoi.bloom- pi-Nlu nfes. Sixty birds that died m the piesent incident were examined for PCB n-sidui s by Monks Wood and three other labora* tones and ten apparently healthy guillemots were i.liol lor comp,-native study Most of The dead buds analysed were guillemots. the remainder comprising ta/ndnlls. a mute swan. shag, black headed pull and Kahwiike The results are given in Appendices VI amt VII I he number ol samples is too small to piovidr a meaningful analysis of regional variation in PCB levels in the area of the wreck, but the wide range of variation in the results for all areas is note worthy. The levels in the small sample of razorbills appear somewhat lower than in the guillemots, but there are too few analyses, and too great a variation, for this to be regarded as significant. 33 In Appendix VIII a comparison is made between two small samples of five shot birds (guillemots) and five which died in the wreck as regards the concentrations of PCB and organochlonnes fyund in the liver and the rest of the body. In Appendix IX. which is computed from Appendix VIII. the total body contents of these residues are compared for the shot birds and those that died in the wreck. Although the sample is very small, it is clear that the total body loads of PCB and pesticide residues were broadly similar in healthy birds and those (hat died in Ihe wreck, and that the higher concentrations found in the livers of the dead birds are likely to hove resulted from a redistribution of residues between the organs of the victims, rather than from a generally higher level of contamination. MONS 050555 EAST SCOTLAND 0 m Oil pIHitto *l*e tiNM ov*r 1000 g] toon* WII lAl V 100 ***"*urn* In wbl* 1 | [ 111111 ----- MH !*' O Maximum counts of dead Auks, Sept-Nov. 1969 B MONS 050556 CONCLUSIONS 34 One of the most striking findings of the analytical programme was the presence in the livers of most of the dead guillemots of unusually high levels of PCBs. In contrast to the situation previously recotded in British land and freshwater birds, these levels were higher than those of residues of the orgenochlonne insecticides ODT and diekJrin. A study of the occurrence of these substances in the sea end in marine life confirmed that the birds could readily have obtained them from their normal food, and accumulated them initially in their body fat. There was no evidence that marine life in the Irish See area contained more PCBs then simitar organisms elsewhere in British waters, or that there had been a sudden rise in PCB levels during the summer of t969. Analysis showed that the total amount of PCBs, DDE and dfekJrin in the bodies of an admittedly small sample of apparently healthy soabiids shot outside the area of the incident were as graat or greater than those in the victims of the bird kill. The latter were peculiar only in the high concentration of residuos in their livers. 35 Those findings are meaningful when it is remembered that PCBs and DDE are soluble in fat endVvithin an animal tend to accumulate in the body fat reserves, where their toxicity is of little signi* licence. The seabird victims of the disaster had no body or liver fat: all the PCBs end other organochiorine residues they contained must therefore havu been mobilised with the fat ond passed to the livot. kidney, brain and other tissues. 36 It may be asked whether this mobilised PCB could have caused the damage to the liver and kidney tissues recorded in the postmortem exam* inations. and whether this damage was in itself severe enough to have been the direct cause of death. The similarity between some of the tissue changes in the deed birds and those produced in Bengalese finches, chickens and quails fad with PCBs under experimental conditions certainly sup ports the hypothesis that the observed tissue concentrations could have had this effect. 37 The significance attached to the observed lesions varied, however between the laboratories that examined them. Consistent interpretation was hampered by the lack of information about the anatomy of healthy birds and of those that have died of starvation in the absence of poisoning of any kind. More research is needed, especially on the behaviour of PCBs when fat is mobilised under conditions of stress, and on the fate of PCBs in tissues after death. 38 If PCB poisoning had been the primary cause of death one would expect that the PCB levels in the birds that died would have been greater than in the birds that survived. In practice this would not appear to have been the case, for the sample of 5 apparently healthy birds shot after the incident contained similar amounts of PCB as five randomly*selected birds that died in the incident. On that evidence it seems that, whatever the effect PCBs may or may not have had once they were mobilised, they could scarcely have been the initial cause of tha mortality Concentration of PCB in the liver and kidney could have occurred only after the fat reserves had been mobilised --that is, after the birds had been seriously alfected by malnutrition. The difficulty with this hypothesis is that there appears to have been no shortage of food for the birds in the affected areas at the time of the incident, but again we ere tacking the critical information. The relationship between birds and their food is a subtle one and very little is known about it. 39 We can summarise the story of this incident by saying that although the seabird wreck does not 9 MONS 050557 sttom lo havr originated at one point in space or tune, there is evidence to suggest that most birds died m n broad belt o! wotor along the east coast of lirl'inri at a time when the adults were in moult and therefore vulnerable to additional stress. The wide distribution of dead birds, even after allowing for the effoct of wind and tidal movements, does not support the hypothesis that birds died as a result of contact with a toxic substance at one, or a few, point sourcos Storms certainly brought the main wave of dead and dying birds ashore, but some brandings preceded the bad weather, suggesting it was not the sole t.ausa. Low body weight and malnutrition were more in evidence than any paiurular pathological condition, and history shows that sea-bird wtocks have occurred from natural r.misris befotu pollution could have been a factor. Thu relatively high values ol PCBs in the livers of some dead birds probably arose because they had mobilised their body fat reserves during a period of malnutrition or interrupted feeding. This could have added to the stress imposed by storms, moulting ,md starvation, account for the pathological signs found m liver and kidneys, and may have loaded the odds against recovery. 40 In closing we should return to the point made in the Introduction to this report, namely that avan if pollutants in the seas around our coasts ere not yet sufficiently concentrated lo harm wildlife by them selves, they may on occasions tip the scale between life and death, and the effect of thia precarious situation could be to affect the balance of whole populations. There is as yet no proof that thia is happening but the possibility cannot ba ignored. It would clearly be impracticable to mobilise re sources on the scale they were on this occasion every time there was a hint of trouble (and many reports turn out to ba exaggerated or falsa) as it would lead to a massive waste of money and of the time of skilled people. The solution is a continuous monitoring of selected components of tha environ ment (of which wildlife populations are one) likely to be the most sensitive 'indicators' of pollution hazards. This involves, particularly, a better under standing of tha biological significance of pollutants to which the natural fauna and flora are exposed. NERC. together with the other Research Councils, Departments of Government, universities end the voluntary conservation bodies ere taking steps to meet this problem. 10 HONS 050558 APPENDIX I. Iff PAN 1 MINI Education and Science Participating Dapartmants and Laboratories ORGANISATION LABORATORY OR SECTION WORK UNDERTAKEN Natural Environment Research Council (NERC) NERC: Nature Conservancy NERC: Nature Conservancy NERC: Nature Conservancy NERC: (aided institution) Scottish Marine Biological Association (SMBA) NERC (Research Unit) el University College of North Wales Agricultural Research Council (ARC) Medical Research Council (MRC) Headquarters Headquarters Monks Wood Experimental Station Merlewood Research Station Oban (Dunataffnage) Laboratory General co-ordination, liaison with Departments. - Co-ordination of work of regional and research staff: liaison with voluntary ornithological bodies. Co-ordination of collection and distribution of seabird materiel for study: post modems and analyses for PCBs and organochlorine pesticide residues. Collation, interpretation and analysis of results. Analyses of organs for metals etc. Collection of dead birds, water and plankton samples. Oceanographic Laboratory, Edinburgh Unit of Marine Invertebrate Biology, Bangor Institute for Research on Animal Dieeaees. Compton National Institute of Medical Research. Mill Hill Records of plankton. Counts and collection of birds: studies of bird drift: observations on status of marina invertebrates: collection of fish. plankton and water samples. Post-mortem studies of birds: pathology Post-mortem studies of birds: virology. Ministry of Atjiicullure Fisheries and Food (MAFF) Fisheries Laboratory, Oceanographical data: collation of Lowestoft marina information. Radiobiology Laboratory, Lowestoft Fisheries Laboratory, Burnham on Crouch Veterinary Laboratory. Lasswada Central Veterinary Laboratory, Weybridge Past Infestation Control Laboratory Tolworth Measurement of radioactivity levels in bird tissue. Analyses of water, plankton, invertebrates and fish. Post mortem examination of birds *. virology and bacteriology. Post mortem examination of birds. Analyses of bird tissue for organophosphorus PCBs and organochlorine pesticide residues. HONS 050559 APPENDIX 1 (continued) OH'ARTMENl ORGANISATION LABORATORY OR SECTION WORK UNDERTAKEN Department of Agriculture and f islumes for Scotland (DAFS) Ministry of Agriculture. Northern Ireland Ministry of Technology (now. Department of Trade ar.d Industry) Ministry of Defence Ministry of Development Northern Ireland Non Governmental University of Cambridge University of Liverpool Royal Society for the Prevention of Cruelty to Animals Scottish Society for the Prevention of Cruelty to Animals Royal Society for the Protection of Birds British Trust for Ornithology Seabird Group Beached Birds Survey (Organised by RSPB and Seabird Group) Wildfowl Trust Marine Laboratory Aberdeen Overall co-ordination of menne Muchas Collection of data on plankton, fish. Freshwater Fisheries Analyses of water, invertebrates, fish Laboratory. Pitlochry and 1 bird. * Veterinary Research Laboratory. Belfast Post mortem examination of birds: Analyses for metals, cyanide. organophosphorus etc. Laboratory of the Analyses of bird tissues for PCBs and Government Chemist organochlorine pesticide compounds. Chemical Defence Experimental Establishment Microbiological Research Establishment. Porton Down Amenity Lends Branch Post mortem examinations of birds. chemical analyses and serological and bacteriological investigations. Collection and counting of dead birds. Department of Animal Pathology Marine Biological Station, Port Erin, Isfe of Man Post-mortem examination of birds: bacteriology, virology. Collection of fish, plankton and water samples: counts and observations of birds. Collection and counting of dead birds. Collection and counting ot dead birds. Collection and counting of dead birds, collection of data on birds found dead. Interpretation of ringing returns. Collation and interpretation of records of bird deaths. First produced data about the incident, and much of the information in Table 1 (see paragraphs 12. 13) Post-mortem of dead buds. HONS 050560 12 APPENDIX II Concentrations of matal in sea water and marine life Mean and (range), n number of samples SAMFll Cu EUfffNT n Zn Cd UNITS Sen wAtnr. Cardigan 2 0' Bay (0 9-6 0) San water, Conwny Estuary Sen water. Other sees 3 0 (n 1) (1 20) f 3 6* (2-3--4-9) 3 6 (n--1) (3-5-8) 4, 12-0* <6-4--21 7) 8-8 (n=. 1) (0-06-33) t 1-3* (0-6-3 0) Micrograms/ Kilogram or litre 0-76 (n 1) (002--0 17) f Bodies of seven species of Crustacea (Irish Sen) Bodies of two spucies of trustacea (English south and oast coasts) Bodies of twelve species of mollusc (Irish Sea) Bodies of four species of mollusc (English south and earn coasts) 36 0 (n-7) (1 2-240) (55- 100) (n 26)^ 50 (n 12) (3-270) (10--4000) (n 30)$^$ 2-6 (n- 7) (0-38-13) (6-16) (n 26)4.4. 12-7 (0 -12) (0 76-42) (10-50) <n 30)^4> 72 (n-7) (63-99) 1-6 (n - 7) (048-4-6) (55-200) (n- 26)$$ -- 346 (n- 12) (84--940) (10-10,000) <n-30)$4>$ 12 3 (n== 12) (1 -2--73) -- -- Parts per million (ppm) dry weight Bodies of four species of fish (Irish Sea) Mackerel, (Irish Sea) Cod. (North Sea) Whiting. (North Ssa) Mackerel (English Channel) (6-2-10) (n- 4) (7 5- 10) (n 10) (5--8 5) (n 20) (5 -17 5) (n 20) (6-12 5) (n 20) (0--5 8) (n-4) 50 (n 10) 50 (n 20) 5-0 <rv 20) (2 5--12 S) (n- 20) (62-110) (n~-4) (25-60) (n- 10) (11-18) (n.-20) (13-34) (n- 20) (26 5-60) (n- 20) (0-15) (n=4) -- -- -- -- -- -- Parts per million (ppm) dry weight * Mean figures of measurements mode at twelve sites round Cardigan Bay. 4 Riley & Skirrow., Chemical Oceanography (1965). Range quoted taken from a large number of determinations over a period. $ Riley b Skirrow (1966). Figures obtained in 1938 and now considered to be over-estimates. 44 The 26 samples in this esse comprised 16 lobsters and 10 samples of shrimps. samples in each case included 5 or 6 individuals. Note that in the third section, the sample numbers represent the number of fish analysed. HONS 050561 13 APPENDIX III Element Concentrations in Sea Bird Tissues (bracketed figures are numbers of samples analysed) SAMI'U ItAOORATONYI ELEMENT CONCENTRATIONS IN MICROGRAMS/GRAM ORY (M> OR WET (8) WEIGHT Pb At Hg u Zn Cu Cd Dead guillemots (Merlewood) Itvor|MI 08 kidney |MI (22) 24 mi 40 0 1 -38 0-1--23 0 2 -41011-600 1-100 0 2-13 (21) (21) (21) (21) (22) (21) 40 01 89 01-72 0 2- 82 76-1000 26-76 1 0-12 (14) (14) (13) (12) (14) (12) Shot guillemots (Merltiwood) livor ,M) 0-2-2 6 kidney ,M' (7) 17 in 0 7-20 (7) 01 (1) 0 11-2 (7) 0-1 (1) 0-2-7 (7) 16 (D 48-98 (7) 72 0) 1 9-25 (7) 1 (D 0 1--13 (7) 02 (D Dead guillemots (Bellas!) liver '> 0 5 0 0-90 - -- __ -- - (6) (10) kidney ,flt 0-5 0 0 2-14 - -- -- -- -- (6) (4) Shot guillemots (Belfast) llVIll '> 0 0 7--14 -- -- -- -- -- kidney |HI (2) 0 20 (2) 02 03 -------- (2) (2) Wot weight dma ,n> may be converted to dry weightfM> by multiplying by 4 6. Hi 042-0 84 (4) 0 34 -0 75 (4) -- -- -- _ APPENDIX IV Estimated concentrations of organochtorine residues in sea water and invertebrate marine life SAMI'U inCAUTY ANO DATE NUMIEft OF SAMPLES ANALYSED CONCENTRATIONS: MtCROGRAMS/LITRf OR KILOGRAM PCS D1EL0R1N ft TOTAL 00T Sea watei lush Sea 23*30 Oct 69 Firth of Clyde 1 Dec 69 53 0 01 0 001-0 005 Zooplankton S E Isle of Man Oct 69 Clyde Oct 69 South Minch Oct 69 7 10-30 10 Mussels Clyde Oct 66 (whole, less shell) Scottish coast. Oct 66 English E coast Feb 68 Irish Sea Oct 69 2(10 specimens) 7 (70 specimens) 14 (10 specimens) 17 (8-16 specimens) 200--800 <100--300 10-200 50--100 100--300 60--100 20-140 10 Shrimps ' Thames Estuary Spring 69 12 (25 specimens) 10-200 20--140 Norway lobster Irish Sea Oct 69 Clyde Oct 69 W Coast Scotland Oct 69 3 (11 specimens) - 10--100 10--100 MONS 050562 APPENDIX V Range of concentrations of oryenochlorine raalduaa In fish tissues (bracketed figures ere numbers of samples end total numbers of individuals sampled) SAMPII Herring Muscle Liver LOCALITY ANQ PEtlQO Irish Sea -Clyde before Oct 69 Other areas before Oct 69 Irish Son Clyde before Oct 69 Other areas before Oct 69 CONCENTRATIONS IN MICROGRAMS/XItOGRAM WIT WEIGHT PCS DKIDRM b TOTAL ODT 10- 1,600 100-- 6,000 '100-- 2.600 10- 100 (4:32) (8:64 (3:22) (1:1) 109010100- 900 (4 :32) 300 (8:64) 800 (4:32) 300 (5:41) Hmung Muscle Liver Whole Fish insh Sea--during and after Oct 69 Other areas--during and after Oct 69 Irish Sea--during and after Oct 69 Other areas--during and after Oct 69 Irish Sea - during and after Oct 69 <10-- 2.600 (3:30) 150 300 (2 :20) 20- 200(10:114) 10- 300 (10:114) 10-- 2.000 (3:30) 20-- 300 (2:20) 10- 1,900 (7:70) 10- 400 (7:70) 10- 2.000 (3:154) 10- 1.000 (3:154) Whiting Muscle Liver lush Sea before Ocl 69 Other areas- before Out 69 Insh Sea- before Oct 69 Olher areas - before Oct 69 10- 600 (7:45) 10 (11 55) 100-27,000 (7:45) 100- 5,000 (11 :65) 10- 140 (7:45) 10 (11:55) 130 - 5.000 (6:25) 300- 3.000 (11 :55) Whrtrng Muscle Liver lush Sea--during and after Oct 69 Insh Sea - during and after Oct 69 10-- 400 (3:18) 10 (1:5) 1,000-- 7,000 (2:15) 1,000- 2.000 (1 :5) Cod Muscle Irish Sea -before Oct 69 Liver Irish Soa -before Oct 69 300- 1,800 (1:8) 400- 520 (1 :5> 4,500-60.000 (1:5) 2,300-'12.400 (1 :S) Ofhei fish* Muscle Liver Whole fish lush Sea during and after Ocl 69 lush Sea- during and after Oct 69 Irish Sea -during and after Oct 69 6-- 400 (6:44) 160-- 6,000 (5:41) 100- 1.000 (3:83) 10 100 (8:44) 30-- 2,000 (3:18) 40- 1,000 (3.53) `Includes spurt, sanded, whiting. mackerel, long rough dab end grey mullet. HONS 050563 15 APPENDIX VI Concentrations of organochlorine residues in guillemot livers n number of birds examined, mean, number of samples and (range) given HICAIITY. TIMl (IF COLLECTION. AND NUMBER OF BIROS (XAMINEO ESTIMATED ORGANOCHIOMNE CONCENTRATIONS IN MICROGRAMS/KIL06RAM WET WEI6NT PCB ODE DIELDPHN A>hv 28/ 9-21/10 n 3 2.000 (3 samples) -- - Clyde 1/10-23/10 n 19 129,000 (8.000--880.000) (19 samples) 9,900 (1,700-17.000) (11 samples) North-East hulend 14/10-29/10 n 5 14.000 (8.000 -20.000) (5 samples) 6,400 (2.300-11.000) (5 samples) 250 (200-300) (4 semplea) L.islorn lush Soa 23/10 3/11 n- 7 161.000 (80.000-230.000) (7 samples) 22,000 (20,000 -25,000) (2 samples) 260 (tract--500) (2 tamplas) North-west Wales 7/10-22/11 n 13 *6,0)0-300,000) (13 samples) 10,000 (4,500-19.000) (7 samples) 600 (300-800) (4 itmptu) South Wales 25/10 n 2 325,000 (260.000--390,000) (2 samples) Overall average 28/9 -22/11 n 49 111.000 (2.000-880.000) (49 samples) 10,200 (1700--25.000) (25 samples) 400 (trace--800) (10 samples) 1 * ' , APPENDIX VII Estimated levsta of organochlorin* pesticide raaiduas and PCBa In llvsrs of seabirds. SPECKS LOCALITY DATE FOUNO ESTIMATED LEVELS OF ORGANOCHIORINES |tN PPM| PCB DOE HE00 (OtELDMNl Razorbill Cumberland 12.11.69 20 12 <1 Razorbill Cumberland 12.11.69 44 9 ^1 Razorbill Cumberland 13.11.69 16 5 *1 Razorbill Cumberland 14.11.69 40 10 <1 Razorbill Cumberland 14.11.69 10 6 <1 Razorbill Anglesey 25.10.69 2 -- -- Razorbill Pembroke 4.11.69 12 4 <1 Mute Swan Kittiweke Anglesey Co. Down 25.10.69 28.10.69 -2 10 -04 0 1 Black-headed Gull Cheshire 1.11.69 6 05 M Shag Co. Down 28.10.69 0 0 1 0-1 Where a dash appears, substance concerned was not looked for. ^ c Multiply figures by 1,000 to give micrograms per kilogram. nund usum APPENDIX VIII Concentration of organochlorine raaiduoa In tlaauaa and whole birds (guillemots). SAMPK tONCIHTWTWlTm WA (WET WllQHT) " ' (EACH FIGURE IS THE ARITHMETIC MEAN OF FIVE BESUtTSRANGE IN BRACKETS) PCB___________________________________ DOE OIELDHIN ' ' Shot birds B..dt found dond Liver Rest of body Liver Rest of body 0-4 (2--0) 3-4 (7--1) 56(200--10) ___ 37 (10-1)0 92 0 24(0-4--0*1) 1 46 (3 1--0*6) 10 80 (25--4-5) (2-0 4) 0-16 (0 4--trace)* 0 54 (1 0--0 2) 0 54 (0 8--0 3) 0-10 (0-4--trace) APPENDIX IX Estimated total body content of PC Be and organochlorine pesticide residues in guillemots found dead and In apparently healthy blrde. Computed from data In Appendix VIII ESTIMATED TOTAL BOOT CONTENT (MICR08AAMS) MEANS AND (RANGES) PCB DDE OIELDRIN Guillemots found deed 2.700 (800--8900) 673 (314--1535) 62 (6--232) GuillsinoiK shot 3.500 1,484 545 (800--7,200)__________ (468-3,211)____________(156-990) HONS 050565 \niural I nvironmrni Hesemrrh ( ouncll. Alhamhre House. 27 .U Charing Cross Hoad. I ondon WC 17