Document 3Q64RXk88qkQqxzBeQO7v60e3

^c_ SEA BIRD WRECK m THE IRISH SEA AUTUSV3SM 1969 THE NATURAL ENVIRONMENT RESEARCH COUNCIL STLCOPCB4010487  n "i ... i n -j j n 3 3 a i 3 SEA BIRD WRECK IN THE IRISH SEA AUTUMN 1969 1 Tins iepoit is about the deaths of over 12.000 sea birds. mostly guillemots. winch wore; washed up on Hie slioies o( Hie Irish Sea and its approaches in the autumn ol 1 969. Il describes the mam leatuies of the incident, the investigations that wne put in hand to ascertain the causes, and the conclusions that emeiged 2 The incident moused public concern at the time and much speculation as to its cause. This is understand.ihle People me growing increasingly enno'iniHl about then environment and the tai -reaching criMsepin,mces that human interference with it can have Hie sight ol oiled birds on out benches is imluituiiately only too common these days: hut (I' Pe'ssHKi though it is. at lenst the cause is obvious. When beaches over a considerable aiea become si-alien'd with unusually large numbeis ol dead or dyin-) buds of which no more than fifteen per cent are oiled, and when the test sample to he analysed i ont.uns substantial residues of chemical substances (l'i)l\i lilniiiiated biphenyls) the biological effects of whir h ,ne little known, it is iiptu that the mailer shunlil he thoroughly mveshgalud 3 I he Nature Consei vaney aclmp in consultation wall the voluntary bodies (paiapiaph 8) repotted these lacts to the Headpuaiters of the Naluiill F nvnor.merit Research Council in the middle of Oi tabor 1869. following ,i piess slatemenl by the Rny.il Sociely (oi die thnleclinn ot birds Them lollmved mi investip.ition uivolvuip some thirty iiuitinis.ilinns and Inlun.il.nirs wod mg in collahoia- (ion with the voluntary societies. The woik was planned and the results collated at two nt.ijcjr meet ings convened by the Secretary ol NERC at Council Headpuaiters, one on 24 October and the Other on 11 November. 4 The outcome as is reported in what follows, is that nu single factor natural ur artificial can ~be regaroca with certainty ns the maid c3TTCE~of the ---tricidedl. Dieie have been similar sea-bird v\^PCks '"in the past, before pollution can have been a possible cause. Widespread evidence of malnutrition was found among ihe dead birds in this incident but there was no evidence of shortage of the (ish on which they leed: much morn knowledge of the feeding habits of guillemots is however needed before these apparently contradictory facts can be 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 ol Ihe period), and may have been ngriinvated by the toxic effects of Ihe metallic and organic residue's found m many ol the dead hiids. But no one ol these faciors can alone be regarded as the decisive cause ol the incident. 5 It is guile possible that tins is Ihe true explanation of the mystery -ie that several different factors in combination were responsible. II 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 biiri 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 NERC) winch collaborated has been edited by Dr M W Holdgale who at the time 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 arc concerned with pollution problems. Particular as pects will also be published in scientific journals by the investigators concerned. DSU 026527 ,'f'r ' ' T hi' Wtrik nf in ihr fnsh Sri r \ ' / i! tin > t uri/i,, t<`,( i,i ifi r thr ,u/\/urr.< nt ihr N.itut if f rivifniriimi f{r\r irh < ,m/u >. f-Itr.l hv fit ' STLCOPCB4010488 ORGANISATIONS PARTICIPATING IN THE INVESTIGATION 7 1 lie Nntur.il Erivuonment Research Council (NtRC). which acted as general co-ordinator for this investigation has as its Prime function the scientific study and conservation of (tie natural envnonnu'iit and its resources. Research with this (iliji i live is promoted by llie Council at a number of institute's and hy (pants to univeisitios. That which is i.imremed with the investigation of tfie dynamics of wildlife populations must clearly lake account of tin | (i-.sihle eflcct ol pollutants as well as of natural ,iiim". .is I.n.tors mlluunr.mg the stability of those iipiil.ilions 8 Within NERC. the Nature Conservancy is Britain's official wildlife conservation body, but the country is fortunate in also having voluntary con servation organisations especially concerned with burls, notably the Royal Society for the Protection of Duds (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 addihon. oflicers ol the Royal Society for the Pre vention of Cruelty to Animals (RSPCA) and its Scottish counterpart, (SSPCA). members of focal natural history societies and Trusts for Nature Con servation, and people Irom universities as well as private individuals helped in counting the casualties on the beaches and in collecting material for post modem examinations. The voluntary ornithological bodies also collected the records and prepared detailed casualty lists Dr W R P Bourne of the Seabird Group collated and edited the evidence fmin all these soutccs. 9 because the incident involved fish-eating sea hurts while they weru at sea. suspicion was at the tun.- understandably directed towards the marine fuivunnmuni. Tor that reason the Fisheries Research I alinmiones ol both the Ministry of Agriculture. I ishTn-s and food (MAFF) and the Department of Aiiiuuliuie and Fisheries of Scotland (DAFS) were Mm rii\ involved from the outset and played a major i ut m the investigations Mi B B Parrish, Director of i'u- DAf S Mannu Lahoratoiy. Aberdeen, co-ordinat'-rt the collection ol samples of seawater and of m.nine Me (including the small fish on which the InliG let'll). 10 On the laboiatory side of the sltidy, post-mortem ex animations of the victims were carried oul mainly In die Monks Wuotl t xpeomenlal Station ot the N.iiu'e Conservancy and the Department of Animal I'.itln ilegy ol Cambridge Universily, and also by the MAFF Veterinary laboratories at Lasswade, the Central Veterinary Laboratory at Weybridge, the Laboratory ol the Ministry of Agriculture of Northern Ireland in Belfast, and the Wildfowl Trust. Tests for the presence of viruses and bacteria were 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 labora tory at Lasswade and the Central Veterinary 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, and 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 ol sick and dying birds on the shores of Northern Ireland early 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. Standings 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 all traced to local spillages. Ninety per cent 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 alt 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, ft is clear that a dramatically large number of deaths occurred only around the Irish Sea and its approaches. The small 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. Am // .<>in n fv /,! the f'loiottion of Buds, the Hntish Trust for Ornithology end the British Ornithologists' Union DSW 0 2 6 5 2 8 STLCOPCB4010489 13 lit- I,-lilies m 1 apli: l me subject to various -14f11 . I mi mu.an r> iMi: total number of birds ii ,nrii'ii m miuIIi vu.'si Scolland where the greatest nn" in." i amp ashore, is derived from sample counts m "I.- on selected sections of beach to give an i st.n an rl Imure tor the whole coastline. The ai . in.ii.v ol the total of 17.34 7 dead birds depends l.iii|i ly on ttin accuracy of tire estimate for guillemots huii'il m SW Scotland, and to a lesser extent on sun.I.n estimates (Isowlurin What can be said with 11 ii.unty is that more than 1? 000 dead birds probuhn i .uni' ashme round tin; Irish Sen in the three ni.uiths horn August to November, and the evidence i I i igi'd birds provided hv the BTO. supports the . i tti.ii i1 t- dead buds came mainly from colonies . siuit'iem gad ol the lush Sea. Because some i i. iv in have sunl1 or dulled into the oj>on . mu. dm intul in.iy well have been much higher ; mf oun'holugists estimate the death toll as high a. SO 000 100.000 birds. 14 Confronted with an incident of this kind, it is naiural to search for precedenis Two species ofien involved in large scale wrecks in the British Isles, and indeed in the North Atlantic generally, are Leach's petrel (Occanodroma teucorrhoa) and the little auk (Plautus a//e). At least forty little auk. 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) are wrecked far less 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 arc rare. 15 Previously recorded wrecks of large euk6 in the British Isles are summarised in Table 2 (page 4) TABLE 1 Estimates and counts of dead birds on the beaches i Vlnst of these figures are based on the Beached Bird Survey organised by the RSP8 and the Seabird Group) .'"IIIIS Observers Divers and Grebes Manx Shearwater EAST * SCOT LAND 10 1 -- IASI ENG LAND 24 4 - SOUTH WALES NW ENGLAND fNG.AND WIST SCOT LAND 23 67 22 49 -- 13 -- - 34 -- ISLE Of MAN 6 -- -- IRELAND TOTAL 21 222 --9 --7 WINGS COL LECTED POST MOR TEM ---- ---- ---- f iflm.ir 5 1 - - 1 -- -- -- 7-- 1 (i imu/l 633 75 33 5 35 -- -- fh'imonmt. Shag 21 1 46 3 2 -- 19 1 1 l' tJ('k s V.'.iili'i-. < tib (>u'i ........... . t (lull 13 3 - 3-- 31-- 2 5- 23 1 1-- 6 3- -- 6 -- 2-- 27 8 2 16 18 66 5 23 -- 14 -- 17 -- 88 1 1 -- -- 1 l.( thill ; at A", ike ' D .lls I. "n U |." Ull.It *i ` -1 35 57 13 31 n4 17 20 2 44 -- -- 1 19 -- 1 1 24 13 2 25 -- 2 1 11 -- 1 1 9-- 1 1- 1 -- ---- 6-- --- 1 36 35 14 2 41 142 15 8 5 2019 898 11,816 320 1794 16,889 528 112 ''M i of uni(it*nlifi vii 'y 1- 30 1 3- 1 38 _ TOTALS 102o 69o 17o 21281 990o 11,850 1 341 o 1850J 17,3471 545 128 1 ' i " ivl nif, ol leg.uns M'u map. page 0 ` Guillemot figures partly based on estimates oBased on counts. 3 DSW 0 2 6 5 2 9 I I STLCOPCB4010490 None of these wrecks closely parallels the events of 1969. The incident in 1859 was somewhat similar m 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 killed mainly rn/otbills oven though guillemots were abundant in the area. The total death roll was probably less than in 19C9 although the auk populations are believed to fiave been many times larger a century ago. The wreck in 1689 is very poorly documented but also seems to have happened just after the breeding season and may have coincided with severe qales. The symptoms of the birds that died in the highly local wreck in the Solway in 1907 seem reminiscent of those in 1969, and 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 Augusl-September. These have often coincided TABLE 2 Wrecks of the larger auks in British waters DAtt 1856 (11 May) PtACI North Norfolk MAIN SPfCltS OTHER SPECIES MORTALITY guillemot razorbill, puflin, gulls Targe numbers' (240 counted in 2 miles) 01MR DBSIRVAlirmS Severe north-westerly gales in early May. Remarkable as no auks breed in the vicinity. 1858 North Norfolk guillemot (September) puffin, razorbill. scoter, divers 'large numbers' 1858 (date Cornwall uncertain) puffin not stated Targe numbers' 1869 (alrout August) Western Scotland (Clyde to Belfast Lough) 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 year) England and Scotland razorbill none (noted at lime) 'Many' ca. 1889 (late summer) Ailsa Craig larger auks 'massive' (many thousands ?) Deaths alter leaving breeding places said to have greatly reduced population. 1895 (AuguslSeptember) Loch Leven (Argyll) guillemot. razorbill not stated Some birds blown inland by gales.. 1907 (AugustScptember Solway Firth guillemot razorbill heavy and prolonged Young and old guillemots . some razorbills. Came closo inshore or stranded in helpless condition. In good plumage but emaciated with empty stomachs. 1911-1913 Ailsa Craig. guillemot. Rathlin Island. razorbill St. Kildn puffin, kiltiwake 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 DSW 026530 I STLCOPCB4010491 vmI'i kIomi'v Wf'.ttlnT which may have been the pumaw rausc in some coses bul in others mav have driven nsboie or despatched birds that had already been weakened by other factors such os disease or malnutrition The largei auks, both adults and young are flightless (m moult or with growing leathers) and at sea during tins period. THE INVESTIGATION 17 ii ir fust step war, to u-view what was happening at tire tune m the natural environment, the weather, tlii- sea currents the state of marine life, and especially the abundance of the fish on which the finds feed both at the time of the incident and in the months landing up to it If the deaths weie due to purely natural causes, there ought to be evidence of something olse amiss in Ihe Irish Sea during tins penotl 18 Although Ihe main strandings of the dead and dying bi'ds coincided wilh the stormy weather in the last weeks of Seplembei. over a hundred came ashore before the onset of the storms This suggests that many birds were already weak or dying before the gates began. Tfie storms may have increased Ihe sliess on the birds and raised the mortality, besides bringing many more victims to the beach, but they appear to have been n secondary rather than a prime or the sole cause of the deaths. A contributory factor could have been the mouliing of tfie birds as already indicated (paragraph 1 6). 19 An examination of the abundance and distri bution of (he fish species on which the birds normally depend foi food was underlaken, and a search made loi 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 loo little of the detailed feeding behaviour of the birds or of the particular combinations of weather and sea conditions which affect the birds' feeding success, for these negative results to be conclusive. 20 Tho condition of the birds--Bird wrecks in the pasi have been attributed to disease and some of the features of the 1969 incident suggested that an epidemic of some kind might have occurred. These features included Ihe apparent sickness of tho finds observed befoie the main peak of rieallis, tfie kick of precise conformity between the pattern of deaths and the pattern of storms, and the way in which the numbei of deaths built up and then died away. Tissues from some 46 guillemots and one rn/odiill. common gull, herring gull and kittiwake ilia! diet) in ihe disaster, and from nno apparently healthy auillemot that was shot, were therefore submitted in mictohiologicnl examination, but tests for pathogenic viruses and bacleria proved negative in all cases. Disease cannot however, be wholly eliminated as a cause of the disaster because of the time that unavoidably elapsed between the deaths ol many of the birds and their arrival at tho laboratories, but the tests provide no evidence for this as a cause of death. 21 Post mortem examinations were carried out on 129 seabirds (112 being guillemots) and one mute swan; and as healthy specimens were needed for comparison. 18 guillemots were shot late in the autumn. All the laboratories agieed that die auks that died in the incident weie in a poor stale of nutrition. Their fore guts and muscular stomachs were empty, in contrast to ihose of the shot birds which contained either fish or the residues of a recent meal Almost all 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 dead birds lacked subcutaneous fat, end most had wasted breast and thigh muscles. More unusual and perhaps more significant were changes found in the livers and kidneys of the birds that died in the incident. All the livers were dark and full of blood, and detailed microscopic investigation of five of them showed unusual 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 the divergence of view was probably due to the small number of samples that it was practicable 1o examine in many cases, the partly-decomposed state of much of the material, and the 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 tfiere was no evidence of specific disease or of oil poisoning. They also concluded that in no case could death be attributed directly to starvation. However, a poor to very poor state of nutrition was characteristic of all their sample of birds, and they concluded that thoy had not led adequately for some time and had been drawing heavily upon their body reserves. 23 The specialists at the Central Veterinary Labora tories, who were 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 ihe liver was a poison of somo kind This 5 DSM 026531 j I I i STLCOPCB4010492 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 lesion was thought to be striking and unusual, and it may be significant that similar symptoms have been observed in chicks fed with PCS in an experiment. 24 The workers at the Compton laboratory, in contrast, noted no macroscopic losions in any of their birds, and reported that there were no signs of obvious disease. They concluded that the deaths wote duo to starvation. 25 The programme of analysis--A large part of the effort of the laboratories who collaborated in investigating the 1969 seabird wrock was devoted to chemical analyses. Samples ol sea water, and marine life of all kinds as well as the tissues of the seabirds ihemselves were analysod lor toxic substanc.os. The reader who is interested in the results ol these analyses will find them in Appendices II to IX at the end of this report, and only a short account of the work is given below. A complete account of the laboratory methods and results is 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 smaller than is statistically desirable. 26 Metallic residue*--Traces of many metallic elements are naturally present in animal tissues but are toxic in excess. Analyses for four metals in seawaior and marine life are given in Appendix II. A comparison with the figures shown there for samples from other areas indicate that the Irish Sea and its marine life do not appear to carry higher concentra tions of these metals than the other coastal regions of Britain which have so far been examined. Appendix III shows the concentrations of various metals found in the livers and kidneys of guillemots. Some of the dead birds showed relatively high levels of trarticular metals and in some cases the highest concentrations wore 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 overlap. 27 These analyses were of course undertaken before the presence of mercury residues in imported tinned tuna fish attracted publicity in the autumn of 1970. The levels of mercury, lead, cadmium and arsenic in the livers and kidneys of some birds are unquestionably high, although they may have been elevated by shrinkage of the organs after death and they should not be taken as precise indicators of the situation in the goneral seabird population. Nevertheless such observations of high tissue con6 cremations in ptedoiors should alert us to the possibility of hazardous levels of these potentially toxic substances in British inshore waters. All these metals are in fact natural components of sea waier in minute amounts, and more research is needed to indicate whether these background levels have been raised to significant amounts by pollution. 28 Organic insecticides and PCBs--Some of the first analyses of dead birds carried out at Monks Wood Experimental Station confirmed the presence of residues of the organochlorine pesticides DDE (8 breakdown product of DDT) and dieldnn and suggested also that unusually high concentrations of polychlorinated biphenyls (PCBs) were present in the livers. An extensive programme of analyses for the organochlorines end PCBs in sea-water, marine life and sea 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 hirds Seabirds as long-lived animals, coming at the end of such a food chain, can acquire large quantities of organochlorines even when these are present in the environment at very low concentra tions. When such birds come under stress, or sutfer from shortage of food, they draw on their reserves of body fat and so mobilise accumulated residues, which pass into the bloodstream and so reach, and may affect, important organs. Birds containing significant amounts of organochlorine pesticides, even when not otherwise stressed are known to suffer disturbances of their calcium carbonate metabolism and behaviour, lay thin-shelled eggs, and have a lower breeding success than normal. 30 PCBs ere not pesticides. In this country they have a wide variety of uses in industry. They are. however, organic compounds containing chlorine, have the same 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 organo chlorine pesticides, but preliminary experiments indicate that they can have similar effects although they appear to be somewhat less toxic to birds than DDT. 31 The concentrations of PCBs and organo chlorine pesticide residues in sea water, invertebrate marine life and fish from the general area of the bird-kill wore not unusually high and were generally within the range observed previously in this area and elsewhere. The concentrations of DDT and DSM 026532 STLCOPCB4010493 111 rl< l! hi tisli wiir mostly lower than 11 tost.* ol I'Cfls lln: results, an: set out in Appendices IV mid V 32 The Humilities and significance of organoi iiIihiiii.' pi stii.ide residues in Bntish wild Ivuds have lieen studied lor needy ten years by a number ol laboratones and especially at the Nature ConM'tvanc.y s Monks Wood Experimental Station, so tlml lliftio is a pood basis lor comparison. Particular .mention has been paid to ihe concentrations found hi the livcis and eqqs ol buds of prey and freshwater lisli rains Midi as the tiemn Since 19G6, most Iin miens have been lesled (or PCBs as well as Ini nniannt him me peslii ulus. Sixty buds that died m lit-- piesenl incirlent were examined for PCB n sulu'r, by Monks Wood and three other lahoiatunes and ten apii.mnllv healthy quillemots wore iii>1 Ini (..ompaiahve study Most of the dead buds an.itysi'd wen: guillemots. the itrmamder comprising la/nibills a mute swan, sliaq. black headed pull and Kiinwahr I be resulis are qivon in Appendices VI and VII Ihe numbn of samples is too small lo |uovule a meaningful analysis of icpionnl variation III PCB levels in the aiea of die wieek. but ||,(> rarujo ol variation in the results foi all areas is note worthy. The levels in tire small sample of rozoibills appear somewhat lower Ilian in the quillemots but iherc ate too low analyses, and too gieat a variation, for (Iris 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 orynnochlorines fpund in the liver and the rest of the body In Appendix IX, which is computed from Appendix VIII. the total body contents ol these residues are compared lor the shot buds and those that died in the wreck. Althouph 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 that died in the wreck, and that the higher concentrations found in the livers ol the dead birds are likely lo have resulted (tom a redistribution of residues between the organs ol the victims, rather lhan from a generally higher level of contamination i DSW 026533 STLCOPCB4010494 I DSW 0 2 6 5 3 4 <2> OH pollution prnt Omllti 100 lUglon* uwd in tbl 1 ||||jjj|^ ovr 1000 ffl IDO-999 \K 10 90 >i 1-9 4 N o Maximum counts of dead Auks, Sept.-lMov. 1969 8 STLCOPCB4010495 i r i CONCLUSIONS 34 One of the most striking findings of the analytical programme was the presence in the livers ol most of the dead guillemots of unusually high levels of PCBs. In contiast to the situation previously recorded in British land and freshwater birds, these levels were highei than those of residues of the ouianochlonne insecticides DDT and dieldrin. A study of the occurrence of these substances in the sea and in marine life confirmed that the birds could readily have obtained them from their notmal food, and accumulated them initially in their body fat. Thete was no evidence that marine life in the Irish Soa Brea contained more PCBs than similar organisms elsewhere in British waters, or that there had been a sudden riso in PCB levels during the summer of 19G9. Analysis showed that the total amount of PCBs, DDE and dieldrin in the bodies of an admittedly small sample of apparently healthy sunbeds shot outside the area of tire incident were os gieat or grnnler than those in the victims of the bud kill. The lattei were peculiar only in the high concentration of residues in their livers. 35 ih. ise findings are meaningful when it is remembered that PCBs and DDE are soluble in fat and Within an animal lend to accumulate in the body fat reserves, where their toxicity is of little signi ficance. The seabud victims ot the disaster had no body or liver fat: all the PCBs and other organochlorine residues they contained must tlicrcfoie have been mobilised with the (at and passed to the livei. kidney, brain and other tissues. 36 It may be asked whether this mobilised PCB could hjvc caused the damage to the liver and kidney tissues recorded in the post-mortem exam inations, and whether tins damage was in itself seven: enough to have been the direct cause ol death. The similarity between some of the tissue changes in the dead birds and those produced in Bengalese finches, chickens and quails fed 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 researefi is needed, especially on the behaviour of PCBs when fat is mobilised under conditions of stress, and on the fate oi PCBs in tissues after death. 38 If PCB poisoning had been the primary cause of death one would expect that die 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 thal 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 the mortality. Concentiation 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 effected t>y 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 are lacking 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 ol this incident by saying that although the seabird wreck does not in *0 Q 9 i 1l I I i STLCOPCB4010496 MJfin lo have originated at one point in space or time, there is evidence lo suggest that most birds died in a broad licit of water along the east coast of I't'land at a limn whim the adults were in moult and thirrclore vulnerable to additional stress. The wide distribution of dead buds, even after allowing for the effect of wind and lid.il movements, does not support the hypothesis that birds died as a result of contact with a toxic substance at one. or a few, point sources Storms certainly brought the main wave nf dead anrl dying birds ashore, but some stiandmgs preceded the bad weather, suggesting it was not the soli ( ause. Low body weight and malnutrition were mom in evidenre than any p.utirular pathological condition, and history shows that sna-bird winks have occurred from natural lauu.-s lielnm pollution could have been a factor. Tlit: relatively high values oI PCBs in the livers of some dead birds piohahly arose because they had mobilised their body fat reserves during a period of malmitution 01 interrupted fpe.ding This could have added to the stress imposed by storms, moulting and starvation, account for the pathological signs found in liver and kidneys, and may have loaded the odds againsi recovery 40 In closing we should return to the point made in the Introduction to this report, namely that even d pollutants in the seas around our coasts are not yet sufficiently concentrated to harm wildlife by them selves. they may on occasions tip the scale between life and death, and the effect of this precarious situation could be to affect the balance of whole populations. There is as yet no proof that this is happening but the possibility cannot be 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 be exaggerated or false) 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 the 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 o( the biological significance of pollutants to which the natural fauna and flora are exposed. NERC, together with the other Research Councils. Departments of Government, universities and the voluntary conservation bodies are taking steps to meet this problem. - sw 026536 10 STLCOPCB4010497 APPENDIX I. ihi'Ari'.hni Education ami Science Participating Departments and Laboratories ORGANISATION LABORATORY OR SECTION WORK UNDERTAKEN Natural Environment Reseaich Council (NERC) NEFtC: Nature Conservancy NEHC: Nature Conservancy NERC: Nature Conservancy NERC: (aided institution) Scottish Marine Biological Association (SMBA) NERC (Research Unit) at University College of North Wales Agricultural Research Council (ARC) Medical Research Council (MRC) Headquarters General co-ordination, liaison with Departments. Headquarters Monks Wood Experimental Station Merlcwood Research Station Oban (Dunstaffnage) Laboratory Co-ordination of work of regional and research staff: liaison with voluntary ornithological bodies. Co-ordination of collection and distribution of seabird materia! for study: post modems and analyses for PCBs and organochlorino 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 Diseases, Compton National Institute of Medical Research, Mill Hill Records of plankton. Counts and collection ol birds : studies of bird drift: observations on status of marine invertebrates: collection of fish, plankton and water samples. Post-mortem studies of birds: pathology Post-mortem studies of birds: virology. Ministry of Agriculture Fisheries and Food (MAFF) Fisheries Laboratory, Oceanographical data : collation of Lowestoft marine information. Radiobiofogy Laboratory. Lowestoft Fisheries Laboratory. Burnham on Crouch Veterinary Laboratory, Lasswade Central Veterinary Laboratory, Weybridge Pest 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. OSW 026537 11 I i i STLCOPCB4010498 APPENDIX 1 (continued) Oll'AlllMINl 0RGANISA1I0N IAB0RA7DRY OR STHION WORK UAOIRIAKtN Department oI Agriculture and Fishenes for Scotland (OAFS) Ministry of Aijncultuii'. Northern'Ireland Ministry of Technology (now. Department of Trade and Industry) Ministry of Defence Mimstiy of Development Northern Ireland Non Governmental University o( 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 marine studies 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 Lands 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, Isle of Man Post-mortem examination of birds: bacteriology, virology Collection of lish, plankton and water samples : counts and observations of birds Collection and counting of dead birds. Collection and counting of dead birds Collection and counting of dead birds, collection of data on birds found dead. interpretation of ringing returns. Collation and interpretation of recoids of bird deaths. First produced data about the incident, and much of the information in Table 1 (sen paragraphs 12, 13) Post-mortem ol dead birds DSW 026538 12 STLCOPCB4010499 APPENDIX II Concentrations of motal In sea water and marine life Mean and (range), n - number of samples SAMPII tu ELEMENT UNITS Pb In Cd Sea wolei. Cardigan 2 0* Hay (0 9 -6 0) Sea wnler. Conway Fsluniy Sea water. OU'ci seas 3 0 (n 1) (1 20)1 3 6* (2 3-4-9) 3 6 (n 1) (3 5-8)<}) 120` (6-4--21-7) 8 8 (m 1) (0-06--33)1 1 -3* (0 6-3 0) 0 76 (n 1) (0-02-0 17)1 Micrograms/ Kilogram or litre Bodies of seven species of Crustacea (Inst; Ben) Bodies of two species ol c.iustacea (Lnplish south and oast coast si Bodies of twelve species of mollusc (lush Sen) Bodies of (out species of mollusc (f nglislt south and east coasts) 36 0 (n 7) (1 2-240) (5b- 100) (n 26)$<j) 50 (n 12) (3-270) (10--4000) (n 30)^xji(j) 2-6 (n 7) (0-38-13) 72 (n- 7) (53-99) 1-6 (n 7) (0-48-4-6) (5-15) (n 26)4>4> (55-200) (n= 26)4>4> 12-7 (n 12) (0 76--42) (10-50) (n 30)4<4>4> 345 (n 12) (84--940) (10--10,000) (n- 30)4>4i4> 12 3 (n -12) (1-2--73) -- Parts per million (ppm) dry weight Bodies of four spec ms of fish (lush Sea) Mackerel, (Irish Sea) Cod, (North Sea) Whiting, (North Son) MarVetcl (English Channel) CT> ro 1 o (n 4) (75 10) (n 10) (5-8 5) (n 20) (5-17-5) (n 20) (5-12 5) (n -20) (0-5-8) (o -- 4) 50 (n 10) 50 (n 20) 50 <n 20) (2 5-12 5) (n 20) (62-110) (n -4) (25-60) (n- 10) (11-18) (n- 20) (13-34) (n- 20) (26 5-60) (n- 20) (0-1-5) (n --4) -- -- -- -- -- -- Paris per million (ppm) dry weight * Mean figures of measurements made at twelve sites round Cardigan Bay. * Riley ft Skirrow., Chemical Oceanography (1965). Range quoted taken from a large number of deietminations over a period. 4> Ififey ft Skirrow (1965). Figures obtained in 1938 and now considered to bo over-estimates. 4>4> The 26 samples in this case comprised 16 lobsters and 10 samples ol shrimps. tj'tj>i|)1 In; samples in each case included b or G individuals. Note that in the thud section, the sample numbers ropicscnt the number of fish analysed. DSW 026539 i flI l> f, J r > t i t t i ! }l 13 STLCOPCB4010500 APPENDIX III Element Concentrations in Soa Bird Tissues (bracketed figures are numbers of snmplos analysed) NAMI'U aAU0HA10HY1 III MINI CONCENTRATIONS IN MICROGRAMS/DRAM DRY |M) DR WET IB) WEIGHT PL As Hij Sb Zn Cu (tend guillemots (Morlewood) livoi lMl 08 kidney ,M| (22) 24- (11) 40 0 1-38 0 1-23 .0 2- 410 11--600 1-100 (21) (21) (21) (21) (22) 40 0 1 -8 9 01-72 02- 82 76-1000 26-76 (14) (14) (13) (12) (14) Cd 0 2--13 (21) 1 0-12 (12) Shut guillemots 1 Merlewood) liv;r (M) 0 2- 2 6 kidney IM` (7) 17 (1) 0 7-20 (7) 01 (D 0 11 -- 2 (7) 01 (D 0 2- -7 (7) 16 (D 48-98 (7) 72 (1) 1 9-25 (7) 1 (D 0 1-13 (7) 02 0) . Dead guillemots (Belfast) liver 1,11 0 5 0 0-9 0 (6) (10) kidney <U| 0 50 0 2-14 ---- ---- -- -- .-- (6) (4) Shot guillemots (Belfast) liver "" 0 0 7--14 (2) (2) kidney ,B) 0 20 0 2-0 3 -- -- -- -- -- (2) (2) Wet weight data may be converted to dry weight ,M) by multiplying by 4 6. Ni " 0 42-0 84 (4) 0-34--0 75 (4) __ __ APPENDIX IV Estimated concentrations of organochlorine residues in sea wator and invertebrate marine life SAMf'U Sen wain IRCAUTY AN0 OAK lush Sen 23-30 Oct 69 Firth of Clyde 1 Dec 69 NUMBER OF SAMPLES ANALYSED 53 CONCENTRATIONS: MICROGRAMS/UTRE OR KILOGRAM PCB DltlORIN b TOTAL DOT - 0 01 0 001 -0 005 Zooplankton S E Isle of Man Oct 69 Clyde Oct 69 South Mtnch Oct 69 7 "10-30 <10 Mussels Clyde Oct 66 (whoie. less shell) Scottish coast Oct 66 English E coast Feb 68 lush Sea Oct 69 2 (10 specimens) 7 (70 specimens) 14 (10 specimens) 17 (8-1 6 specimens) 200-800 <100-300 10 --200 50-100 100-300 60-100 20--140 10 Shrimps Norway lobster Thames Estuary Spring 69 tush Sea Oct 69 Clyde Oct 69 W Const Scotland Or.l 69 1 2 (2b specimens) 3(11 specimens) 10-200 - 10-100 20-140 10-100 DSW 026540 STLCOPCB4010501 APPENDIX V Kongo o( concentrations of orgnnochlorine residuos in fish tissues (bracketed figures ere numbers of samples and total numbers of individuals sampled) SAMPH Honing Muscle l.iver lOCAUfY AND PfRIOO lush Sen Clyde before Oct 69 Olhei mens bofoie Ocl 69 lush Sen Clyde before Ocl 69 Olhei mens before Oct 69 CONCENTRATIONS IN MICROGRAMS/KIIOGRAM WET~W[7ghT~ PCB OltLORIN ft UITAI 001 10- 1.500 (4:32) 10- 900 (4:32) 100- 5.000 (8 :64 90- 300 (8:64) 100- 2.600 (3 22) 10- 800 (4:32) 10 100 (1 :1) 100- 300 (5:41) HiMnrui Muscle Livci Whole Fish lush Sen- during and after Ocl 69 ' Ollier areas-- duiing and after Ocl 69 lush Sea-during and aller Ocl 69 Other areas- during and after Ocl 69 Irish Sea during and after Oi l 69 <10- 2.600 (3 -.30) ' 150- 300 (2:20) 20- 200 (10:114) 10- 2,000 (3 :30) 10- 1,900 (7:70) 10-- 300 (10:114) 20-- 300 (2:20) 10-- 400 (7,70) 10- 2.000 (3:154) 10- 1,000 (3:154) WIlltM'fl Muscle t.ivei lush Son before Ocl 69 Ollier mens before Ocl 69 lush Sen bofoie Oct 69 Oilier areas before Oct 69 10- 600 (7:45) 10 (11 :55) 100 27,000 (7:45) 100 - 5.000 (11 55) 10- 140 (7:45) 10 (11 .55) 130- 5.000 (5:25) 300- 3.000 (11 55) Wlulmg Muscle Liver Cod Muscle Livei Irish Sen--during and after Ocl 69 Irish Sea - during and after Ocl 69 Irish Sea -before Ocl 69 lush Sea before Oct 69 10- 400 (3:18) 10 (1 :5) 1,000- 7,000 300-- 1,800 4.500 - 50.000 (2:15) (1 :5) (1 :5) 1,000- 2,000 400- 520 2,300- 12,400 (1 :5) (1 :5) (1 :5) Olhei fislt" Muscle Liver Whole fisti Irish Sen -during and after Ocl 69 Irish Sea duiing and after Ocl 69 Irish Sea -during and after Ocl 69 5- 400 (6.44) 150-- 6,000 (5:41) 100- 1,000 (3:83) 10 100 (6:44) 30- 2,000 (3:18) 40- 1,000 (3:53) `Includes sprat. sanded. whiling mackerel, long rough dab and grey mullet. r t li! 1 i | c t fV. V f 1 ii 5 i 5 * r i \ i *r j I DSW 026541 15 !I 1 : I STLCOPCB4010502 APPENDIX VI Concentrations of orgnnochlorino residues in guillemot livers number of birds exnminod, mean, number of samples and (range) given iurAnY liMi or emu chon, and MUMBIH nr BIRDS t XAMINtO ESTIMATED 0RGAN0CH10RINE CONCENTRATIONS IN MICROGRAMS/KILOGRAM WtT WEIGHT PCB ODE DIEEORIN Aujyll 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 tasl licland 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 samples) Lestem Irish Sea 23/10 3/11 n 7 161,000 . (80,000--230.000) (7 samples) 22,000 (20.000 25.000) (2 samples) 250 ~ (trace - 500) (2 samples) North-west Wales 7/10 - 22/11 n 13 87.000 (6.000--300,000) (13 samples) . 10.000 (4.500-19.000) (7 samples) 500 (300--800) (4 samples) 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 (1.700-25,000) (25 samples) 400 (trace--800) (10 sampler.) APPENDIX VII Estimated levels of organochlorine pesticide residues and PCBs in livers of seabirds. SPECKS lOCAurr 0ATI FDUNO ESTIMATED LEVELS OF ORGANOCHLORINES (IN PPM) PCB DDE HFOD |DIELDRIN| 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 Mule Swan Anglesey 25 10 69 -2 -- -- Kittiwake Co. Down 28 10.69 10 04 01 black - headed Gull Cheshire 1.11.69 6 05 1 1 Shag Co. Down 28 10.69 0 0 1 0-1 Where a dash appears, substance concerned was not looked for. Multiply figure s by 1.000 lo give microginms per kilogram DSW 026542 _ STLCOPCB4010503 APPENDIX VIII Concentration of organochlorine residues in tissues and wholo birds (guillemots). SAMPlf CONCFNTHAIION IN PPM (WET WEIGHT) (EACH FIGURE IS THE ARITHMETIC MEAN OF FIVE RESULTSRANGI IN BRACKETS) PCB ODE DIEIDRIN SI>ol buds Buds found dead Liver Rest of body Liver Re'll of body 0-4 (2-0) 3 4 (7-1) 56 (200-10) 3 ? (10-1) 0 24 (0-4--0 1) 1 46 (3-1 -0 6) 1080 (25-4-5) 0 92 (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 PCBs and organochlorine pesticide residues in guillemots found dead and in apparently healthy birds. Computed from data in Appendix VIII ESTIMATED TOTAL BOOT CONTENT (MICROGRAMS) MEANS ANO (RANGTS) PCB DOE ClfLORIN Guillemots found dead 2,700 (800-8900) 673 (314-1535) 62 (6--232) Guillemots shot 3,500 (800-7.200) 1,484 (468-3,211) 546 (155-990) i OSIN 026543 f 'mntut h t ffir VtfiMdf / t h ( Alhomhio tfnttie. 27 J.l Charmf ( pi 1 W `Jt/. / . STLCOPCB4010504