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1 IN THE IRISH SEA
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AUTUMN 1969
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3 THE NATURAL ENVIRONMENT RESEARCH COUNCIL
PUBLICATIONS SERIES C No4 1971
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MONS 035960
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SEA BIRD WRECK IN THE IRISH SEA
AUTUMN 1969
1 tins repot 1 is about (he deaths of over 12.000
mm birds, mostly guillemots, which were washed
ii|> on thu slioies ol (he lush Sea and its approaches
m the autumn ot 1069. ft describes the mam (catuies
01 the incident, the investigations that weie pot in
hand to ascertain the causes, and the conclusions
lh.it oimmjod
'
2 Ihc incident moused public concern at the time ami much speculation as to its cause. This is under standable People aio growing increasingly con i i'nmd about then envnonmcnl and the far-reaching consequences that human inteilerence with it can have The sight of oiled birds on our beaches is oofoitunatHy only too common these days: hut
di'pmssimi thomjh d is. at least the cause is obvious. Wi'n beaches ovet a considerable area become v atii'imi with unusually large numbers of dead or dymii buds of which no more than fifteen per cent
.im oiled, and when the lust sample to be analysed contains substantial lesidoes of chemical substances (pohrhlonnati-d biphenyl*;) the biological effects of which aie little known, it is tight dial the matter shoolh he Ihutoughiv investigated.
3 Ihi: Nature Conseivnncy acting in consultation
with the volant,ny bodies (p.n.iqi.iph 8} rtporh'd these facts to the Hu.iilquailors of the Natural Environment Research Council in the middle of Oi inhei 19G9. following a press statement by the Royal Society fo thu Piotection ot Buds. There followed an investigation involving some thirty otnamsatinns amt laboiatoues working in collabora
tion with thu voluntary societies. Thu woik was planned and the results collated at two major meet
inys convened by the Secretary of NERC at Council Headquarters, one on 24 October and die other on 11 November.
4 Thu outcome as is reported in what follows, is
that no simile factor natural or artificial can be regarded with certainty as the main cause of the incident. Them have been similar sea-bird wrecks 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 feed: much more knowledge of the feeding habits of guillemots is however needed before these apparently contradictory facts can hi:
reconciled. The effect of the malnutrition of the birds was probably compounded by natural causes including moulting, disease and gains (there were high winds during part of the period), and may have been aggravated by the toxic effects of the metallic and organic residues found in many of the dead biids. But no one ol these factors can alone be regarded as the decisive cause of the incident
5 It is quite |>ossiblo that this is the true explanation
of the mystery -it* that sevm.il difforont factors m
combination were responsible. If so. the implications
are not reassuring. It opens die 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 winch is under stress
from some other cause will die rather than recover
Even a small shift in Ihc 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 Hofdgnte who at the time was Deputy Director (Research) of the Natum Conservancy and who also acted ns 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 thu investigators concerned.
MONS 035961
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ORGANISATIONS
PARTICIPATING IN
THE INVESTIGATION
7 Ihe Natui.il Environment Research Council
(NlflC). winch acted as general co-ordinator for this investigation, has as its Prime function the scientific study and conservation of the natural envitoument and its lesouices. Research with this oh|iTitvc is promoted by the Council at a number of institutes and by giants to universities. That which is i.oni.eined with the investigation of (he dynamics nl wildlife populations must clearly take account of ih. possible effect of pollutants as well as of natural . .nr i". .is l.tuors mllimncinq the stability of those
|>< pill.iliOns
8 Within NERC. the Nature Conservancy is
Britain's official wildlife conservation body, but the country is fotlunatc in also having voluntary conseivanon organisations especially concerned with buds, notably the Royal Society for the Protection of Dads (RSPB). the British Trust for Ornithology (RIO) and the Soobird Group (a specialist group sponsored by the three major ornithological socie ties) * All those contributed to the investigation. In addition, officers of the Royal Society for the Pre vention of Cruelly to Animals (RSPCA) and its Scottish counterpart. (SSPCA), members of local natural history societies and Trusts for Nature Consoivation, and people from universities bs well as pnvatc individuals helped in counting the casualties on the beaches and in collecting material for post modern examinations, The voluntary ornithological iHKiins also collected the records and prepared duiailed casualty lists Or W R P Bourne of the Seabed Group collated and edited the evidence Ihhii all these sources.
9 because the incident involved fish-eating sea
beds while they weie at see, suspicion was at the tm< understandably directed towards the marine euvi'nnmiMit. For that reason the Fisheries Research I ,iiwv,(tones of both the Ministry of Agriculture, l isti m s and Food (MAFF) and the Department of A.iin iihuie and Fisheries of.Scotland (OAFS) were (liter th involved from the outsut and played a major pail m the invoMiiiatinnx. Mi B B Parrish. Director of >)ti' PAI S Mamie Lahoratoiy. Aberdeen, co-ordinail'd dm rolloriioo of samplos of seowator and of maiinr Ido (including the small fish on which the tnnl> feed).
10 On the lithnruiotY side of the study, t>ost-inortem
examinations of the victims wete earned out mainly h\ tin* Monks Wood t xpcnmental Station ol the Naium Conservancy and the Department of Animat 2 Pathology ol Cambridge University, and also by the
MAFF Veterinary laboratories at Lasswade. the Central Veterinary laboratory at Weybridgo. the Laboratory of the Ministry of Agriculture of Northern Ireland in Belfast, and the Wildfowl Trust. Tests for the presence of viruses and bacteria were dona 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 Weybridgo. Chemical analyses were done by the Nature Consetvancy 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 sot 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 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. Strandings of smaller numbers ol 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 lo local spillages Ninety per cent of the mortality was among adult guillemots, mostly of the race breeding m the Southern areas of the British Isles. Most of them wore 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. It is clear that a dramatically large number of deaths occurred only around the Irish Sea and its approaches The small numbers fiom 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.
tu>- hovel Siu h'tv lot tho Protection of Buds, the Bntish Trust for Ornithology and the British Ornithologists' Union
MONS 035962
13 n.,, p.iu'u* m l.iUlo 1 me subject to vjuous |insuni r* Hu; total number ol birds
sImmiIi ii m soutli west Scotl.ind whore the greatest mo> In* name Ashotu. is derived bom sample counts M,,,(!* on selected sections of beach to give an rstiuMird home loi the whole coastline. The ;u iiiii.v ol the total of 1 7.347 dead birds depends l.tnii |y on the .iccui.iry of the estimate for guillemots li.iimi m 5W Scotland, and to a lesser extent on sum.I.n estimates nkowhme What can be said with ,. .i.nntv is that moie than t 7 000 dead birds prob-
f .mu* aslioie round lint Irish Sen in the three
........ tu.Kii AutiuM to Novemtici. and the evidence
H r .o. ii imds provided bv ilie BIO supports the \ i /. tii.it i't dead birds came mainly from colonies i" " fMii'u'in |mii of the lush Sea Because some
1.. 'v in have sunk oi dulled into the open .. inn. tl i- toi.il may well have* been much higher; omeholoijisis estimate the death toll as high
.i. SO COO 100.000 birds.
14 Confronted with an incident of this kind, it is
nature! to search for precedents. Two species ofton involved in large scale wrecks in the British Isles, end indeed in the North Atlantic generally, ere Leach's petrel (Occanodroma /eucorrhoa) end the little auk (H/autus alle). 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 (puflin. 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 uillemots in the 1969 wreck are rare. $ Previously recorded wrecks of large auks in
the British Isles are summarised in Table 2 (page 4)
TABLE 1
Estimates end counts of dead birds on the beaches
i Most ol those figures mo based on the Beached Bird Survey organised by the RSPB and the Seabird Group)
S'-tMIS
t AST * SCOT
1(AS
ENG-
SOUTH WALES NW
ENGLAND
ENG'-ANO
WIST
scot
tsu OF
1JRELANn TOTAL
WINGS POST COL MOR
LANO UNO
LAND MAN
LI CUD TEM
Observers
10 24 23 67 22 49 6 21 222 -- -
Divers and Giobes
1
4-
13 - --
9-
-
Manx Shornwnlor
-
-
-
34 - - -
7-
1 iilm.tr
5 1 1- -
- --
7- 1
lVnmct
633
1 1Comuomim. Shag
2
75 46
33 5 3; 2 -
35 -- 19 1 1
Purls
13 3 -
3-
31-
23 - 1
V\.lllT.
2 6-
23
1 1-
14 - -
( Hit (mil
6 3 6- - --
-
2-
17 - -
1*. -mi i (mil
27 8 2 16 18
6 6 5 88 1 1
1 1 S .11
3 5 2 4 4 - - 1 19 - 1
11t . .W **.
5 7 1 24
1 3 2 25 - 2
Cm Ik
1 3 1 11 - 1 1
9- 1
t. n I. mp.ll
3 1 1-
1 - --
6-
-
9 4 1 36 35 14 2 41 142 15 8
.,1*; . -n
17 20 5 2019 898 11,816 320 1794 16.889 528 112
............... unufpntihvd 2
1 -
30 1
3 - 1 38 _
TOTALS
102c 69o 17o 21281 990o 11.850* 341o 1850' 17,347t 645 128
t. ..ml m >l irpionssee map page 8 'Guillemot figures partly based on estimates oBased on counts.
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HONS 035963
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Nono cf thoso wrecks closely parallels (he events of
seems to have happened just after the breeding
1909. The incident in 1859 was somewhat similar
season and may have coincided with severe gales.
in that it occuired off south-west Scotland in late
The symptoms of the birds that died in the highly
s
summor. just allot the birds had left their hreeding
local wreck in the Solway in 1907 seem reminiscent
#
grounds. However, it is said to have killed mainly ra/ot hills oven though guillemots were abundant in
of those in 1969, and the timing is similar as it was in 1941.
I the men. The total death roll was probably less than
in 1969 although the auk populations are believed
16 It seems clear, therefore, that there have pre
to have been many tunes larger a century ago. The
viously been wrecks of the largor auks in ihe period
wrock in 1689 is very poorly documented but also
August-Septembor. These have often coincided
TABLE 2
Wrecks of the larger euke in British waters
tlAll pt Art
MAIN SWCIIS OTHCR SPtCICS MORTALITY
OTHIR OBSSRVATMNS
18V)b (11 May)
Notlh Norfolk guillemot
razorbill, puffin. gulls
large numbers' (240 counted in 2 miles)
Severe north-wesierly gales in early May. Remarkable as no auks breed in the vicinity.
1Bb8
North Noifolk guillemot
(September)
puffin, razorbill, scoter. divers
'large numbers'
1858 (date Cornwall uncertain)
pufltn
not stated 'large numbers'
1859 (about August)
WoMern
razorbill
Scotland
(90%)
(Clyde to
Belfast Lough)
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 ynr)
England and Scotland
razorbill
none (noted at time)
'Many'
ca. 1889 (lato summer)
Ailsa Ciaig
larger auks
'massive' (many thousands?)
Doaths after leaving breeding places said to have greatly reduced population.
1895 {AugustSeptember)
Lochleven (Argyll)
guillemot. razorbill
not stated
Some birds blown inland by gales
1907
(August* September
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.
191M913
Ailsa Craig.
guillemot.
Rathlin Island. razorbill
St. KiMn
puffin. kitliwako
progressive decline in breeding populations
Gannets on Ailsa Craig unaffected as were seabirds generolly in Shetland. Orkney and east coasi.
1941
Firth ol Clyde guillemot not
(September)
recorded
about 2.000
MQNS 035964
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vw!m niouny weather which may have been the pnmuiy < ausu in some cases but in others may have driven ashore or despatched birds that had already born weakened by other (actors such as disease <>r mftlmitrinon The largo* auks, both adults and young. are flightless (in moult or with growing hinihml and at sou dtiriwj tins period.
THE INVESTIGATION
17 T hr* lust slop was (o review what was happening
.it (lie time in tho natural environment; the weather, pi. Mia currents, the stale of marine life, and CMHtctiilly the abundance of the fish on which the hints feed both at (he time of the incident and in the mniiihs I'Mriing up to it If the (tenths were due to purely natural causes, there ought to be evidence of something olso amiss in (lie Irish Sea during tins
period
18 Although the main strandings of the dead and
dying buds coincided with the stormy weather in the Iasi weeks of September, over a hundred came ashoto before lire onset of the storms. This suggests tli.it many birds were already weak or dying before thn gales began. The storms may have increased the slim on the birds and raised the mortality, besides bringing many more victims to the beach, but they appear to have been a secondary rather than a prime or the sole cause of the deaths. A contributory factor could have been the moulting of the birds as already indicated (paragraph 16).
19 An examination of the abundance and distrt*
hution of the fish species on which the birds normally depend for food was undertaken, and a search made lor ovidonce of `blooms' of phytoplankton or toxic algae which might be poisonous to guillemots. No evidence ol a food shortage or of an abnormal abundance of toxic algae was found. But we know ton little of the detailed leading 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 The condition of the birds--Bird wrecks in
the past hflvo been attributed to disease and some ol the features of the 1969 incident suggested that an epidemic of tome kind might have occurred. Thus features included the apparent sickness of the birds observed before the main peak ol deaths, tho hick of precise confmmity between the pattern of deaths and tho pattern of storms, and the way in which the number of deaths built up and then died
away. Tissues from some 46 guillemots and one
ra/oibillv common gull, honing gull end kittiwake that died in the disaster, and from ono apparently heallhy guillemot that was shot, were therefore submitted to microbiological examination, but tests
for pathogenic viruses and bacteria proved negativo 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 of many of the birds and their arrival at the 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 mule swan; and as healthy specimens were needed for comparison, 10 guillemots were shot late 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 were empty, in contrast to those 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 betweon half and two thirds that of apparently healthy birds. The dead birds lacked subcutaneous fat, and 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 incidont. 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 en experiment at Monks Wood.
22 The different laboratories did not entirely agree
in the interpretation they pul upon their post mortem findings, although much of the divergence of view was probably due (o the smalt number of samples that it was practicable to 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 end 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 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 they had not fed adequately for 6ome 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 materiel from e 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 was a poison ol some kind. This
5
MONS 035965
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toxin could have been absorbed from the intestines
possibility of hazardous levels of these potentially
and carried by the blood to the liver and kidneys,
toxic substances in British inshore waters. Alt theso
where it may have had a specific toxic effect on the
metals are in fact natural components of sea water in
veins and tissues around them. The hepatic lesion
minute amounts, and more research it needed to
wnt thought to be striking and unusual, and it may
indicate whether these background levels have been
bo significant that similar symptoms have been
raised to significant amounts by pollution.
observed in chicks fed with PCB in an experiment.
24 The workors et the Compton laboratory, in
28 Orgenle insecticide* end PCBe--Some of
the first analyses of dead birds carried out at Monks
contrast, noted no macroscopic lesions in any of
Wood Experimental Station confirmed the presence
their birds, end reported that ihere were no signs of
of residues of the organochlorine pesticides DOE
obvious disease. They concluded that the deaths
(a breakdown product of DDT) and dirfkfnn and
wore duo to starvation.
suggested also that unusually high concentrations of
25 The programme of anelyaie--A large pert of
the effort of the laboratories who collaborated in investigating the 1969 seabird wreck was devoted to chemical analyses. Samples of sea-water, and manne lifo of nil kinds as well as the tissues of the seabirds thomseives were analysed for toxic sub
polychlorinated biphenyls (PCBs) wero present in the livers. An extensive programme of analyses for the organochlorines and PCBs in sea water, manne life and sea birds was therefore carried out. The results are given in Appendices IV to IX.
29 The organochlorine pesticides may hava con
stances. The roadcr who is interested in the results
siderable effects on living tissues, but their back
of theso analyses will find them in Appendices li
ground level' in the environment i6 normally well
to IX at the end of this report, and only a short
below that likely to harm wildlife. However, their
account of the work is given below. A complete
solubility m fet causes them to be accumulated in
account of the laboratory methods and results is
the fatty tissues of animals. Aquatic plants end small
provided in the full report and supplement alresdy
marine organisms contain only minute amounts of
referred to in the Introduction. Caution is needed in
these compounds, but their concentrations increase
inteipreting the data as the number of specimens
as they pass up the food chain to predators such as
it wos possible to examine was small in relation to
fish or birds. Seabirds as long-lived animals, coming
the total seabird mortality and indeed smaller thr.n
at the end of such a food chain, can acquire large
is siatistically desirable.
quantities of organochlorines even when theso are
26 Metallic reelduee--Traces of many metallic
present in the environment at very low concentra tions. When such birds come under stress, or suffer
elements are naturally present in animal tissues but me toxic in oxcess. Analyses for four metals in seawator and marine life are given in Appendix II. A
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
comparison with the figures shown there-for samples
may affect. Important organs. Birds containing
from other areas indicate that the Irish Sea and its
significant amounts of organochlorine pesticides,
i marine life do not eppear to carry higher concentra tions of these metals than the other coastal regions
even when not otherwise stressed are known to suffer disturbances of their calcium carbonate
of Britain which have so far been examined.
metabolism and behaviour, lay thin-shelled eggs,
Appendix III shows the concentrations of various
and hava a lower breeding success than normal.
metala found in the livers and kidneys of guillemots.
P
Some of the dead birds showed relatively high levels of particular metals and in soma cases the highest
30 PCBs are not pesticides. In this country they
have a wide variety of uses in industry. They are.
t concentrations were above the level at which poison
however, organic compounds containing chlorino
5 ing may hava occurred. In general the range in the casualties of the incident end in healthy birds shot
have the tame properties of persistence, fat solubility and biological activity as DDT and dieldrin, and can
I- for comparison overlap.
27 These analyses ware of course undertaken
be concentrated in food chains. Their effects on birds are less well known than thoso of organo chlorine pesticides, but preliminary experiments
j before the presence of mercury residues in imported ' tinned tuna lish attracted publicity in the autumn of
indicate that they can have similar affects although they appear to be somewhat less toxic to birds
1970. The levels of mercury, lead, cadmium and
than DDT.
arsenic in the livers end kidneys of some birds ere
unquestionably high, although they may hava baen
31 The concentrations of PCBs and organo
elovatod by shrinkage of the organs after death and
chlorine pesticide residues in sea wator. invertebrate
'*
they should not be taken es precise indicators of
marine life end fish from the general area of the
ii
the situation in the general seabird population.
bird-kill were not unusually high and were generally
Nevertheless such observations of high tissue con-
within the range observed previously in this area
6 cfmtraiions in predators should alert us to the end elsewhere. The concentrations of DDT and
i MONS 035966
n a
a
Q
a Q
E3
Q
9
n
a
a
a
a 9 !
J
iIm'IiIiim id fish wen' mostly lower than (hose of I'CBj. 1 hi* insults arc set out in Appendices IV .md V
32 Die uu.intilies ,iml sipmlicnnce of orqano-
ihlunnr pesticide residues in British wild birds h.ivo been studied for nearly ten years by a number of laboiainnes and especially at the Nature Con st'ivancys Monks Wood Experimental Station, so that ilieie is a pood basis for comparison. Particular attention has been paid to the concentrations found in the livers and epps of beds of prey and fmshwater lish I'lteis such as the limon Since 1966. IVOSl .penmens have been tested for PCBs as well as |,,i <>i.|(iiHii tilonne pi".Ik ides Sixty buds that died nt the piesent incident wen* examined for PCB lesidui s by Monks Wood and three olher inborntones and ten apparently healthy puillemots were shut hu v.o'npiuative study Most of the dead buds analysed wen* puillemots. dm lemainder comprising la/mhills a mute swan. shap. black headed pull and Katiwake Dm insults are piven m Appendices VI and VM llm mimhci of samples is loo small to piovide a mc.inmglut analysis ol ronionnl variation
in PCB levels m die aiea ol die wmtk. hot the wide range of variation in the results for all areas is note worthy. The levels in the small sample nf ta/orhilk appear somewhat lower than in the puillemots. but theic ore too few analyses, and too great a variation. for this to be regarded as significant.
33 In Appendix VIII a comparison is mode bciween
two small samples of five shot birds (guillemots) and five which died in the wreck as regards the concentrations of PCB and organochlorines fpund n 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 compaicd for die shot birds and those that died in the wreck Although the sample ts very small, it is clear that the total body loads of PCB and pesticide residues were broadly similar in healthy turds and those that died m ihe wreck, and that the hipher concentrations found in the livers of die dead bods mu likely to have resulted from a redistribution of residues between the organs of the victims, rather than from a generally higher level of contamination
<J
0. ,M..
100 *>* VMOlAUbtol
jk ^
I0DIII 1-0
(g w (i
Maximum counts of dead Auks, Sept.-Nov. 1969
i
o jt
1
3
3
a
3
34 One of the most sinking findings of the
Bengalese finches, chickens and quails fed with
II analytical progiammo w;.s the presence in the livers ol most of the dead guillemots of unusually high
PCBs under experimental conditions certainly sup ports the hypothesis that the observed tissue
lewis of PCBs. In contrast to the situation previously
concentrations could have had this effect
iocokIcmI in British land and freshwater birds, these
37 The significance attached to the observed
lovols wmu higher than those of residues of the
lesions varied, however between the laboratories
oiyanochloune insecticides ODT and dieldrin. A
that examined them. Consistent interpretation was
study ol the occurrence of these substances in the
hampered by the lack of information about the
soa and m marine lilo confirmed that the birds
anatomy of healthy birds and of those that have died
could readily have obtained them from their normal
of starvation in the absence of poisoning of any
food, and accumulated them initially in their body
kind. More research is needed, especially on the
lat. There was no evidence that marine life in the
behaviour of PCBs when fat is mobilised under
Irish Sea area contained more PCBs than similar
conditions of stress, and on tho (ate of PCBs in
organisms clsowheio in British wafers, or that there
tissues after death.
had boon a sudden rise in PCB levels during the
Summer of 19G9. Analysis showed that the total amount of PCBs, DOC and dieldrin in the bodies of an admittedly small sample ol apparently healthy seahitds shot outside the area ol the incident wore ns great or greater than those in the victims of the bird kill. The latter were peculiar only in the high concentration ol residues in their livers.
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 haal'hy birds shot after the incident contained similar amounts ol PCB as five randomly-selected birds that died in the incident, On that evidence
35 These findings arc meaningful when if is
remembered that PCBs and DDE arc soluble in lat ond Within an animal tend to accumulate in the body lat reserves, where their toxicity is of little signi ficance. Tho soabnd victims of the disaster had no body or live) fat: alt tlm PCBs and other orpanoChlonne residues they Contained must therefore
have !>ocn mobilised with the (at and passed to the iivm. kidney, brain and oilier tissues.
it seems that, whatever the effect PCBs may or may not hove had once they were mobilised, they could scarcely have been the initial cause of the mortalily. Concentration of PCB in the liver and kidney could have occurred only after the fat reserves had been mobilised -that is, alter the birds had been seriously oflocted 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 tho time of the incident, but again we are lacking
36 H may ho asked whether Pus mobilised PCB
could have caused the damage to the liver and
kidney tissues recorded in the post-mortem exam inations. and whether tins damage was in itsell
the critical information. The relationship between
birds and thoir food is a subtle one and very little
is known about it.
39 We can summarise tho story of this incident
severe enough to haw been the direct cause of
by saying that although the seabird wreck docs not
MONS 035969
i
sucni io have originated at one point in space or tunc. there is evidence to suggest that most birds died in a broad boh of water along the* east coast of ln'l.imt at a time when the adults were in moult and ihtmdor* vulnerable to additional stress. The wide (listnt)ution of dead birds, even after allowing for the effect 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 sources Storms certainly brought the main wave of dead and dying birds ashore, but some
standings preceded the had weather, suggesting n was not the sole < ause Low body weight and malnutrition wore more m nvidenre than any p.uitrular pathological condition, and history shows that sea-bird wiucks have occurred from natural i.iu.es before pollution could have been a factor Hie (datively high values of 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 (ceding This could have added to the stress imposed by storms, moulting and starvation, account lor 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 m
the Introduction to this report, namely that even if pollutants in the seas around our coasts arc not yet sufficiently concentrated to harm wildlife by them selves, they may on occasions tip the scale botween life and death, and the effect of this precarious situation could be to affect the balance of whole populations. There is as yei no proof that this is happening but the possibility cannot be ignored. It would clearly hn impracticable to mobilise ro 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 masstvo 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 of the biological significance of pollutants to which the natural fauna and Mora are exposed.
NERO, together with the other Research Councils. Departments of Government, universities anc the voluntary conservation bodies are taking steps to meet this problem.
10 MONS 035970
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APPENDIX I.
(llPARtMlNl Eilur.it ion end Science
3
1
3 3
3 I
Participating Department# and Laboratoriaa
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 (Resoarch Unit) at University College of North Wales Agricultural Research Council (ARC) Medical Research Council (MHC)
Headquarters
General co-ordination, liaison with
Departments.
*
Headquarters
Monks Wood Experimental Station
Merlewood 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 material for study:
post modems and analyses for PCBs and organochlorine pesticide residues. Collation, interpretation end 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 of 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.
,
! j t i $ ^ ' } t
t
i Ministry of Agriculture Fisheries and food (MAFF)
1
Fisheries Laboratory. Oceanographical data: collation of
Lowestoft
marine information.
Radiobiology Laboratory, Lowestoft Fisheries Laboratory, Burnham on Crouch Veterinary Laboratory,
Lasswado Central Veterinary
Laboratory. Weybrfdge 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.
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HONS 033971
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APPENDIX 1 (continued)
UH'AWMINI
QRGANISAflON
lABQRATOflV OR SfCTIUN WORK UNDIRTAKfN
Department of Agriculture and Fisheries for Scotland (DAFS)
Ministry ol AgnCiilhm*, Northern Ireland
Mmislty ol Technology (now, Department ol Trade arid Industry)
Ministry ol Defence
'
Ministry of Development Northern Ireland
Non Governmental
University ol Cambridge
University of Liverpool .
Royal Society (or the Prevention ol Cruelty to Animals Scottish Society lor the Prevention of Cruolty to Animals Royal Society for < ' the Protection of Birds British Trust for Ornithology Seabird Group
Benched Birds Survey (Organised by RSPB and Seabird Group) Wildfowl T rust
Marine Laboratory Aberdeen
Overall co-ordination ol marine studies Collection of data on plankton. h$h
Freshwater Fisheries Analyses of water, invertebrates, fish
Laboratory. Pitlochry and 1 bird.
-
Veterinary Resoarch Laboratory. Belfast
Post mortem examination ol birds Analyses lor metals, cyanide, organophosphorus etc.
Laboratory of the
Analyses of bud tissues for PCBs and
Government Chemist organochlorinc pesticide compounds.
Chemical Defence Experimental Establishment Microbiological Research Establishment. Porton Down
Amenity Lands Branch
Post mortem examinations of birds, chemical analyses and serological and bacteriological investigations
Collection and counting of dead Imds
Department of Animal Pathology
Marine Biological Station. Port Erin. Isle of Man
Post mortem examination of birds bacteriology, virology. Collection of fish, plankton and water samples : counts and observations ul birds. Collection and counting of dead birds.
Collection and counting ol dead birds.
Collection and counting of dead birds, collection ol data on birds found dead.
interpretation of ringing returns
Collation and interpretation of records of bird deaths. First produced data about the incident, and much of the information in Table 1 (see paragraphs 12. 13)
Post-mortem of dead birds.
12 MONS 035972
APPENDIX II
Concentration* of metal In sea water and marine life Mean and (rango). n number of samples
SAMPII
EICMENT n Zn
UNITS Cd
Su;i water Gairlignn ? O' liny (09 -6 0)
Sim water Conway fsluaiy Sea WflU,'l, Othri sues
3 0 (n 1) (1 20)1
3 6" (2 3--4 9)
3 6 (n 1) (35-8)$
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)
{0 02--0 17)1
Bodies of seven spent's of crustaceo (Irish Sir.O Bodies of two sgunes of ccustac.ea (Luplish south and oast coasts) Bodies ol twelve
sperms ol mollusc (lush Sen) Bodies of four species of mollusc (I nglish south and nasi coasts)
36 0 (n 7) (1 2-240)
(b(i- 100) (n 26)i|><t>
50 (n 12) (3-270)
(10-4000) (n 30)<f>4>4>
2 0 (o 7) (0 38-13)
72 (n= 7) (53--99)
1-6 (n 7) (0 48-4 6)
(6-- 16) (n 26)4>4>
(55- 200) (o- 26)$$
12 7 (n 12) (0-76-42)
(10 -- 50) (n 30)4>4)4>
345 (n 12) (84--940)
(10-10,000) (n -30)$$$
12 3 (n =12) (1 2--73)
Parts per million (ppm) dry weight
Bodies ol low species ot fish (Irish Sea) Mackerel. (Irish Son) Cud, (North Sou)
Whiling, (North Sea) Mm.koiol (English Channel)
(6 2-10) (n 4) (7 5 10) (o 10) (5 -8 5) (n 20) (5 - 17 5) (n 20) (5--12-5) (n -20)
(0-5-B) (n4) 50 (n 10) 50
(o 20) 50
(o- 20) (2 5-12 5) (n 20)
(62-110) (0 4) (25--60) (0- 10) (11--18)' (0 "20) (13-34)
<o- 20) (26-5-60)
(n 20)
(0--1 5) (n-4)
--
-- -- --
_
--
Parts per million (ppm) dry weight
* Menu figuios of measurements made at twelve sites round Cardigan Bay. ' Riley & Skirrow.. Choroical Oceanography (1965), Range quoted taken from a large number of
determinations over a period. 4> Hiloy ft Skirrow (1965). Figures obtairmd in 1938 and now considered tc be over-estimates
4 llui 26 samples in this case comprised 16 lobsters and 10 samples ot shrimps. <j>^4>1he samples in each case included 5 or 6 individuals. Note tint in the thud section, the sample numbers represent the number of fish analysed.
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APPENDIX III
Element Concentrntiorts in Sea Bird Tissues (bracketed figures are numbers of samples analysed)
SAMI'lt (MDORATOHtl
lit MINT CONCtNTRAllONS IN MICROGRAMS/GRAM DRY (M| OR WIT (8) WHGHt Pb At Hq Sb it, Cu
Cd
Dead guillemots
(Mmlewood)
liver,M>
08
Kidney ,Ml
(22) 24-
<">
40 0-1-38 0 1-23 .0 2-- 41011-600 1-100
(21)
(21)
(21)
(21)
(22)
40 0 1 8 9 0 1-7 2 0 2- 62 76 1000 26 76
(14)
d)
(13)
(12)
(14)
0 2-13 (21) 1 0-12 (12)
Shot guillemots
(Merlewaod)
llVIM
02
p)
Kidney IM'
17
(M
20
0 7 -20 (7)
01
(1)
0 11--2 (7)
01
(D
0 2-7 (7) 16
(1)
48--98 (7) 72
(1)
1 9-25 (7)
1
(1)
0 1-13 (7) 02
(1)
Dead guillemots
(Nrltiisl)
livrf ,u*
0 5 0 0-9-0 - - -- --
_
(6) (10)
kidney t"1
0-5 0 0 2--14 -
--
--
--
--
(6) (4)
Ni 0 42-0 84 (4)
0 34- 0 75 (4)
_ --
Shot guillemots
(OelUst) llVUI
0
0-7--1 4 -- -- -- --
Kidney
(21 (2) 0 20 0 2--0 3 - -- -- --
(2) (2)
Wet weight date ,M) may be converted to dry weight tM> by multiplying by 4 6.
-- --
--
APPENDIX IV
' SAMCil
Sea water
Estimated concentrations of organochlorine residues in sea wator and invertebrate marine life
LOCALITY ANO (IAT1
NUMSfROF SAMPLES ANALYSED
CONCtNTRAllONS: MICROGRAMS/UTRt OR KILOGRAM PCS DlllDRIN b TOTAL DOT
Irish Sea 23-30 Oct 69 Futh ol Clyde 1 Dec 69
53
- 0 01
0 001-0 005
Zooplankton
S E Islo 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
,, Noiway lobster tnsh Sea Oct 69
Clyde Oct 69
3 (11 specimens)
'10--100
10-100
W Coast Scotland Oct 69 14 .............
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a a 3 a 3
a a
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i . --- --
O
- Zi l-l--M. --J
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APPENDIX V
R/m^o of connontrafions of orynnochlorlne riiiduot in fiah tissue* (brncketod figures am numbers of samples and total numbers of individuals sampled)
samph
iocauit amd wmnn
CONCINTMTIONS IN MICROGFMMS/KIIOGRAM WtT WflGHT pcb dihuhin b tout ooi
Herring
Muscle I.IVCI
Irish Sen -Clyde before Oct 69 Other mens before Oct 69 tush Sen - Clyde before Oct 69 Othci areas tvcloro Oct 69
10-- 1.500 100- 5,000 100- 2.600 10- 100
(4:32) (8:64 (3 22)
(1:1)
10-90 10--100-
900 (4 32) 300 (8:64) 800 (4:32)
300 (5:4))
Minting
Muscle livCf Whole Pish
Irish Sen- during and after Ocl 69 Ollier areas--during and after Oct 69 Irish Sen- during and alter Oct 69 Other areas -during and after Ott 69 Irish Sea -during and after Ocr G9
<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 Oct G9 Ollier areas- before Oct 69 lush Sen - hetorc Oct 69
Other areas before Oct (>9
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)
Whiting
Muscle Liver
liish Sea- during and after Oct 69 lush Son -during and after Oct 69
10- 400 (3:18)
10
(1:5)
1,000-- 7,000 (235) 1,000- 2.000 (1:5)
Cod
Musclo
Irish Sea -before Oct 69
Liver
lush Sea -Ircfore Oct 69
300 1.800 (1 :5)
400- 520 (1 :5)
4.500-60.000 (1 :5) 2.300 - 12.400 (1 :5)
Other fish * Muscle l.ivor Whole hsh
lush Sen -during and after
Ocl 69 lush Sea -during and after Oct 69 Irish Sea during and after
Oct 69
5-- 400 (6:44) 150-- Q.000 (5:41) 100-- 1,000 (3 :B3)
10 100 (6:44) 30-- 2,000 (3:18) 40- 1.000 (3:53)
'Includes sprat. sandeol. whiting mackerel, long rough dab and grey mullet.
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APPENDIX VI
Concentrations of oryanochlorine residues in guillemot livers o number of birds eNamined, moan, number of samples and (range) given
lUCAl'TY PM! ill CmitCIJON AMO NUMBIH OF BIHDS IxAMINID
Argyll
28/ 9-21/10 n
ESTIMATED DflGANUCHt QUINE CONCENTRATIONS IN MICROGRAMS/KILOGflAM WIT MIGHT PCD 001 OlllDAIN
3 2.000 (3 samples)
--
-
Clyrio
1/10-23/10 n 19
129.000
(8.000-880.000) (19 samples)
9.900
(1.700-17.000) (11 samples)
North- Last hufnnri
14/10 -29/10 n
S 14,000 (8.000-20.000) (5 samples)
6.400 (2.300-11.000) (5 samples)
250 (200-300) (4 samples)
l.tsutrn lush Sen
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)
Northwest 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 Walos 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 samples)
APPENDIX VII
Estimated levels of organoehlorine pesticide residues and PCBs in livers of seabirds.
SPICKS
LOCALITY
OAK FOUND
ESTIMATED LEVELS OF ORGANOCHLQRINES (IN PPM) PCD DDE NfOO (OIHDRINI
Razorbill Rnrorbill Razorbill Ruxorbill Razorbill Ra/orbill Rarorhrll
Cumberland Cumberland Cumberland Cumberland Cumberland Anglesey Pembroke
12 11.69 12.11.69 13.11.69 14.11.69
14.11.69 25.10.69
4.11.69
20 44 16 40 10 2 12
12 9 5
10 6
-- 4
<1 <1 <1 <1 <1 --
<1
Mute Swan
Anglesey
25 10.69
2
-
-
Kittiwaka
Co. Down
28.10.69
10
0*4 0-1
Black* headed Gull
Cheshire
1 11.69
6
0*5 11
Shay
Co. Down
2810.69
0
Where a dash appears, substance concerned was not looked for. Multiply figures by 1,000 to give micronrnms per kilogram.
0-1
01
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___
35 zYih~TF~r~xszzbrr.--
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APPENDIX VIII
Concentration of organochlorine raeidune in tissues and whole birds (guillemots).
SAMPII
CONCENTRATION IN PPM (WET WEIGHT) (EACH FIGURE IS THE ARITHMETIC MEAN OF FIVE RESULTS RANGE IN BRACKETS) fCB DOE 0IE10RIN
Shoi buds Buds found dead
Liver Rest of body Liver Rum of body
0-4 (2-0) 3 4 P-1) 56 (200-10) 3? (10-1)
0 24 (0 4--01) 1 46 (3*1--0 6) 10 80 (25--4-5) 092 (2-04)
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
ESTIMAItn TOTAL BDOY CONTENT (MICROGRAMS) MLANS ANO (RANGES) PCS ODE
OIEIORIN
Guillrmols found dead
2.700 (600--6900)
673 (314-1535)
62 (6-232)
(iinHtmiou. attot
3,BOO (800-7.200)
1.484 (468-3.211)
545 (155-990)
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1'ttnir.l At the S*tuni I MWtttnmrnf lirtentrh ('nwiti'W, Athamhrg House. 77JJ Chanti/t ( >> HuoJ I*4 m w t ` 1 7
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