Document RJ6R6Z9omrBRyKoQeNGyREMwk

Monsanto W. B. PAPAOEOROE - ST. LOUIS JUNE 12, 1970 TO Hn. S?. BDEoRnGuEmNi W. S. CLARK E. V. JOHN R. E. KELLER - SECOND STREET J. MASON D. A. OLSON P. S. PARK W. R. RICHARD J. E. SPRINOOATE E. P. WHEELER --- Attached 1b a copy of the final report by the Natural Environment Reeearoh Council (u.K.) on the Investigation of the seal deathB which occurred last autumn off the Cornish coast. The report concludes that DDT and PCB were found In the seals, but were not responsible for the death of the animals. Death Is attributed to starvation whloh resulted when the seal pups were separated from the mother seals prematurely. ms Attachment MONS 099961 Sal Daatha in Cornwall Autumn 1969 HONS 099964 Foreword Tho occurrence of deaths amongst soal pups in Cornwall in the autumn of 19^9 was investigated by tho Seals Research Unit of M-B-R C. Tho Officer in Charge of the Seals Research Unit gave interviews to the press and informed them of the progress of these investigations. Now that these aro complete, we thought it would be in the best interests of everyone if an extensive account were produced. The following report is not in the strict form of a scientific papor and is somewhat more discursivoj it is hoped that those receiving it will bear this in mind. Nevertheless, the investigations reported and the con clusions reached have been pursued with the utmost soientifio rigour. Aoknowled.temsnts . The Natural Environment Research Council (N E R C.) and the Seals Resoaroh Unit are much indebted for the help they received from people mentioned in tha report, and in particular, for the oo-opergtion they received from Nr. Jones, who rune a seal sanctuary at St. Agnes in Cornwall, and the Royal Sooisty for the Prevention of Cruelty to Animals (R S P C A ). The facilities aooorded by the Ministry of Agrioulturs,.Fisheries and Food (M A F F ) locally were of great assistance and ws are particularly indebted to Mr. A.V. Holden of the Department of Agrioulture and Fisheries for Scotland Fisheries Laboratory at Pitlochry, and to Mr. S.S. Allen of tha Nature Conservancy'e Kerlewood Reeearoh Station for the chemioal analyses. MGNS 099965 Introduction Considerable public ooncern was expressed in the autumn of 1969 follow ing reports of dead and dying seals being washed up on Cornwall shores.. The reports referred mainly to young seals but also to adult seals suffering from lesions which were described as "burn marks". These reports followed closely on the reported deaths of around ten thousand guillemots and other birds of tfoe auk family in the region of the Northern Irish Sea in September and October. Soma of theoe birds were found on examination to have higher lcvelB of some organoohlorins compounds in their livers than are normally detected in routine monitoring, and this lead to suggestions that the seal deathe might be nlinilnrly oonneoted with pollution. The NERC Seale Researoh Unit investigated the event with the help of various other organisations and people. Most reports of seals were received through Mr. K, Jones, who for the past nine years has run a seal oanoturary at St, Agnes, and from Mr. 0. Orlffiths, RSPCA Inspsotor at Pensianco. The MAPS' Veterinary Investigation Centre at Truro carried out some of the post-mortem jxjminntions, was responsible for all the baoteriologoal findings and provided laboratory and offios facilities. Other organisations assisted with analyses of organs and tissues. The pups It hae been stated that more than 50 pup seals have been found dead or dying *n the Cornish ooast. Hr. Jones has given details of 21 reports of seal pups in difficulties, of which he has personally confirmed lfl. Pour pups are ntlll alive in his care. Mr. Orlffiths has recorded 113 seals, plus 4 passed to Mr. Jones. One sioh pup, whloh subsequently died, was reoeivsd from the Isles of Soilly. Thars is thus a total of 40 reports conoerning 36 seals which were either found dead or died Boon afterwards. There wore two reports from September, five from October and the remainder from November and the early part of December, figure 1 shows the distribution of the dead and dying pups. Mr. Jones says that ordinarily thera are reports of R or ? pupa in dlffloultlsB each year and Mr. Griffiths suggests a similar figure; thus reports for 1969 are more numerous than usual. It is not certain to what extent these reports Indicate a true inorease in the number of dead pups. The publicity in the looal and national press, and on television, had the additional effect of oausing a greater proportion of dead senlo to be reported. Dead seals are not usually reported to the RSPCA or Mr. Jones because they are past human aid. . Of the seals whioh died, 9 were subjected to a full post-mortem exami nation and 2 others were professionally examined. Pour living pup# were examined at Mr. Jones' seal sanctuary. One of theeo, collected at Portreath on 4 December, was a fat and healthy pup with an estimated weight of about 60 lbs; it appeared well able to fend for Itself. MONS 099966 A eeoond j>up (7789), capturod the same day at Codrevy, was in poorer condition. It wSighed 42 lbs and had ssvaral bite-markB on its body, similar to thosa inflicted by adult seals on pups not their own which solicit feed ing. There were no signs of gross infection. This seal would huve had small ohanoe of surviving in the wild. It died from aooidental onuses on 5 December. A third pup was captured at Newquay on 26 November and the fourth at St. Agnes on 16 November. These ware fed on a milk/margarine diet with mnokerel. Both were very much understood for weaned pups and probably weighed about 30 lbs. onoh. Mr Jones thought they were not putting on weight properly considering how muoh they ate. One had some superficial eye infeotion from whioh the organisms Corynebacterium pyogenes and Pseudomonas aeruginosa were isolated. Both pups produced a thiok nasal mucus (as did two older seals nt the sanctuary). ThlB muous yielded on oulture an organism of the genus Proteus and Escherichia poll. It is unlikely that any of these organisms was direotly responsible for the poor oondition of the pups. C. pyogenes Is often present normally on muooue membranes and skin; B. ooli and Proteus. both enterobacteria, are widely distributed as non-pathogenio organisms, but may oaues infections, as can Pseudomonne. The remains of a pup oaroass found at St, Agnee on 4 December were examined. The animal had been dead about six weeks and the head and the anterior part of the body were missing. Its weight at death was estimated at about 20 lbs. It was probably either a still-birth or a starveling which had received no milk from its mother. The findings of the post-mortem examination of ten other seals are summarised in Table I. One seal (7709) died from accidental asphyxia. One (6822) was found to be suffering from pneumonia, but only the lungs were available for examination. Two (6007 and 7620) were recorded as dying from, septicaemia. The cause of death of the remainder was diagnosed as atarvation. With the exception of 7709, whioh died from accidental causes, and 7620, the body weights of the remaining seven animals were all 35 lbs. or lose. The average weight of a Grey seal pup at birth is about 31 lbs. and, under normal feeding, it reaohes a weight of between 90 and 100 lbs. by its seventeenth day of life, when it is weansd (Couleon & llickling, I9C4). Most Grey seal pups in Cornwall and the eouth-weet generally are bom in late September and Ootober (Davies, 1997) so that it is highly probable all the pups examined were well past the age of normal weaning. Thus all pups weighed (except 7620) were grossly underfed. 7397. which weighed only 12 lbs, had the lowest weight ever recorded for a Grey oeal pup, ^6?0 was estimated to b 6$ lbs, but ths post-mortem report said there was "some degree of atarvation". Probably this estimate was muoh too high; a pup weighing 65 lho is plump and fat with a well-developed blubber layer and would show no signs of starvation. Various organisms were oultured from ths Baals examined. Escherichia ooli was reoovsrsd from five of the Bpaoimens, Proteus ep. from one and streptococci from two. These organisms are probably normally present as non-pathogens, but they oan lead to septicaemia (as in 6087) in an animal la poor oondition. rasturslla multoelda ( - P septioa ) is pathogenio for a large number of different animals. "Probably the most important role that Pasturslla multooida plays in disease is that of a secondary invader when ths rsoistanoe of the animal has been reduced by various stresses" (Merohant A Paoker, 1967 pp. 339-340). Pasturslla haemolytlca is also an Important secon dary Invader. As with P. multooida environmental faotors are thought to be Important in leading to infeotion. MOWS 099967 2 From four of the animals examined no organisms could be cultured. This waB probably due to tha antlblotlo therapy they had received while in I'r Janes' oare. Samples of tissues from specimens 7843. 7^47 and 7052 wars subjected to a viroloRlcal examination by the Veterinary Investigation Centre, Bristol. Results were all negative. The baotsriological findings show that seal deaths were not due to any epidemio disease. The pneumonia and eeptioaemia diagnosed probably ropre-- sented the terminal etages of a deoline due to lack of food, rather than the infection of an otherwise healthy animal. Diagnoses, weights and bacterio logical examinations indioats that the primary cause of death was malnutrition. As tha animals examined represent 25 per cent of the total reliably reported dead ( a very high percentage for an episode of this kind ) it is justifiable to extend thie oonolusion to the mortality as a whole. Possible causes of this starvation are diaouBsed later. The adult seals at the Lizard Reports wers received of sick adult seals at the Lizard. The Seals Research Offioer visltad tha Lizard and interviewed two people who had seon these seals) the following is a synopsis of their account. A member of the crew of the Lizard lifeboat saw a large seal, about 6 feet in length, on the old slip on the afternoon of 26 November, It appeared to be gasping through its mouth and its nostrllB were opening and closing. Thsre was some white mucus around the nostrils and mouth and the seal wiped at its faoe with its flippers. Patohes of fuel-oil wore present on the body (this ie usually seen on seals in this area) but on the sides of the neck was what Vtas described as a "burnt patch" where the fur had gone. Thie was not the sort of mark that could have been caused by entanglement with a rope. The following day a pup was seen on the slip. The pup appeared to have a aore eye surrounded by mattery grease but it was lively and snapped at the llfeboatman's beets. It is not usual to see eeal pups at the Lizard but Kynanoo Cove and Soapy Cove usually produce a few pupB each year. On 28 November a big seal was seen with a raw band around ito neck. Thiu seal was gasping and its back jerkod in a convulsive way. On the afternoon of 29 November a very big coal was seen on the alin and was approached to within two yarda. Ito upper lip was rolling book and its oyee had a glazed appearance. It wipod its face with itn flippers. The animal gave off steam from its skin. . On Sunday 30 November, throughout the low water in the middle of the day, a very large seal was aehore on a rook. Thia was approached to within three yards. The seal was lively and aggressive and barked at the lifoboatmon. On the right side of its neok was a patch about five or six Indies in diameter, from whloh the hair had gone. The skin was 'rising up' and though it waa not bleeding there was an ooze from it. It wae possible to see the flesh and white fibres. A companion of the llfeboatman, present at the time and who had been corroborating thia account, said that the lesion resembled an over grown cattle ring-worm. On the left side of the neck was a patch of about the same nize. Here the hair was present but was matted by a greasy and mattery discharge. The eeal rubbed at these patohes with its flippers from time to time, MONS 099960 The Ilfsboatroart thought that tha lasiono desoribed wore not ordinary blt wounds* Hs said ths skin had not been torn. He was sure that the adult seals sighted on these four oooasions were all separate animals. A looel fisherman gave a similar, but lesB extensive, account and Biiggenlod that t!' real seen on Sunday might have naught I'." wok lh a lobster pot or a wrsok when hunting for bream or conger. Hone of these seals was seen after Sunday 30 November, A report of seals with "burn marks" round tholr necks at land's End was made to the HSPCA Inspector at Penzance, but the animals could not be looatod. The description given of these lesions tallies with lesions observed by members of the Seals Researoh Unit on both Orey and Common seals off East Anglia and in the Wash. Their aetiology is unknown but their appear ance corresponds with a long-standing uloerative condition of the skin with baotsrial and possibly fungal infection. It is not possible to make a diagnosis of the condition reported in Cornwall as no speoimene have been secured and no qualified persons have seen these seals. A similar ulcerative lesion with neorotic areas has besn described from the dolphin lagenorhvnohus obllquidens (Johnson ft Ridgway, 1969). Pseudomonas aeruginosa was isolated from this lesion; the earns organism was idsntifled from the infected eye of a seal in the present investigation. It seems most likely that these lesions are due to secondary infeotion of a minor wound on a spal that 1b in poor condition. Supsrfloial wounds in seals take a long time to heal aa the lowered skin temperature oaused by immersion in water hinders tissue repair. If tha sealB seen at the Liaard were bulls, which seems likely as all ware deaoribed as large, then the neok lesions were on the area most often wounded during fighting in the breeding season. The signifloanoe of the gasping reported in two of the Beale ie not known. Seals sometimes suffer from lung-worms, but this would cause them to oough, not gasp. I~ ths seals were suffering from pneumonia, as a result of loss of condition and subsequent infection, they might show respiratory distress. Seals never normally inhale through the mouth. Some adult seals might be expected to be in poor condition st the end of the breeding season, but there is nothing to conneot the desoribed condition of ths adult seals at the Lisard with.the reports of dead and dying pups. *. ' Ths question of pollution Mention has been made of publio fears of environmental poisoning, aroused by the deaths of eea birds in the Northern Irish Sea earlier in the autumh of 1969. The existence of a Ministry of Defence (MOD) experimental establishment near Portreath naturally added to this specu lation about pollution. . With this in mind, signs of poisoning were especially looked for. No svidsnos has corns to light that either ths deaths of the pups or ths oendition of the Blok adult Beale were caused by pollution or poisoning, either ohronio or aoute. MONS 099969 5 There were no eigne of gastritis or enterltle (apart from that aeeooiated with eeptloaemia in two oaeee) in any of the pupa examined poot-mortsm. The description of the aidcadult aeala dose not allow diagnosis but it is very unlikely that the lesions observed oould have resulted in ohronio poisoning. It oould be speculated that they wore caused by acute oontaot with a corrosive substance, but it is impossible to substantiate or even Investigate auoh a suggestion with no specimens available, and it is thought probable that these lesions resulted from infeotion of wounds. Tineue samples from ^ of the Cornish eeal imps were analysed for organophosphorus and organoohlorine residues. !!o orgonophosphorus compounds were detected. Organoohlorine compounds lookod for were the pesticides dieldrin and DMT, tho breakdown products DDE and TDK, and a group of substances commonly know as polychlorinated biphenyls or PCDs. These compounds are nil highly lipophilic and hence found dissolved In the body fat. Previous assay for these substances in seals has been by analyeis of blubber samples, but the emaointed at, to or the Cornish seals allowed only liver to bo routinely usoil, though three blubber samples were also examined. Results for liver and blubber agree when corrected for fat content (See Table II). i suckling seal pup may beoaae contaminated with organoohlorinss from residues present in its mother's fat. Such reaiduas might paas through tha placenta to contaminate the .foetus before birth or the pup might bacons contaminated by drinking milk with organoohlorine-contaminated milk fat. The possibility of contamination through the akin exista, but the quantity whioh oould be involved in tha course of tha pup's Ufa would be minute. Although quantitative data are lacking it is believed that the great majority of the organoohlorines found in seal pups that have not begun to feed for themselves have been ingested with the milk and that the oontamination found in the pups therefore reflects the gendral contamination of the eeal stock. It follows from this that the amount of oontamination present In a suckling seal pup depends both on the degree of oontamlnetion of ite mother's milk and the amount of milk it has reoeirad. If for any reason less than the normal mount of milk is taken, tha total does of organochl'orinee obtainad from tha mothor will be smaller than if the pup hed taken a ffall ration of milk. However, if the deprived pup then subsequently starves it will use up what little fat it has but not the dissolved nrgonoohlorines. The result or this Is a rise in the concentration of orgonochlorinee in the fat. The situation is thus extremely complicated. True oorapariaons between organoohlorine concentrations can only be made if tha nutritional status of the animals compared is similar. As. all the Cornish material originated from starving pups, a olaos of animals not MUNS 099970 6 Investigated in earlier work, it was decided to compare the Cornish samples with material obtained from 5 seal pups, 3 well nourished and 2 starving, taken in January 1970 from another oolony. The results obtained (see Table Il)are not easy to Interpret. A comparison of values from the well nourished and starving seals from the Northern oolony shows that the concentration of organochlorines found is higher in the starving pups. As explained earlier this does not imply that the starving seals have received a greater quantity of organoohlorinos than the well nourished seals. In faot the opposite is the case, beoause the utilisation of fat by tho starving animals has oonoentrated the organoohlorlnes into tho small amount of fat remaining. As neither of the starving animals from the Northern sample was as amaoiated as any of the Cornish seals examined (except for 7799), the concentration effect is more marked in the Cornish seals. On the other hand, the well nourished animals from the Northern oolony, having reoeivad mors milk fat containing dissolved organoohlorlne compounds from their mothers* milk, have therefore received a higher total dose of organoohlorines. When the concentrations of the various compounds in the tissues are oompared it is found that dieldrln, DDT and its dsrivatlves DDE and TDE are found in similar concentrations In seal pups from both Cornwall and the Northern colony. Qeoause of tne concentration effect oaused by starvation it seams likely that dleldrin and HOT pollution in Cornwall is not as heavy as in the area from whioh the Northern seale were obtained. MONS 099971 The oaae appears different for FCBe, and CorniBh seals oontaln 3 to 10 times more than the seals from the North but considerably less than seals from East Anglia, where Gray and Coimion seals have been found to oontain between 330 and 520 p.p.m. PCB in their blubber. The difference found in Cornish seals is in the proportion of PCBb to other organoohlorines, but it should be emphasised that the sample is small and the material (starved pups) unusual so no definite oonolusion can be drawn. The toxioity of organoohlorines generally is very imperfectly known. It is believed that when an animal is well nourished, with ample fat reserves, considerable concentrations oan be tolerated. If the animal's nutritional status deolines, fat is metabolised and the dissolved organoohlorines ars released into the blood; such deleterious sffeots as are known concern DOT and dleldrin in birds. PCBs appear to be less toxio to birds than DDT. No information at all is available about the toxioity of organoohlorines to seals but even the most heavily contaminated animals studied, those from East Anglia which oontained 350-520 p.p.m, PCB, 30-36 p.p.m. DDT and 0.8-1.0 p.p.m. disldrin In thair blubber, did not appear to bs suffering from any symptoms that could bs osoribed to poisoning. Tha Ministry of Agrloulture, Fisheries and Food is currently carrying out u monitoring programme to determine the level of organoohlorine com pounds in marine organisms and fish in the South-west. So far no exceptionally high levels have been reported. Other contaminants Other tissus samples from the Cornish nsals were analysed for traces of the heavy metals, araenio, lead and mercury. The results, together with those from the oontrol sample of seals from the second oolony are sat out in Table III. The levels recorded are of the same order as has been reoorded from similar organs from other mammalB, though the mercury values appear higher, but there ars no data for normal levels in seals. Besides the three elements listed in the table, a qualitative scan was mads for other possible toxio elements, but nothing exceptional was dstsotsd. It had been suggested that the . MOD research establishment at Nanoekuke, on the oliffa above Portreath, might be the source of poisonous effluents, but all effluent from the laboratories at Nanoekuke is chemloally treated to render it innocuous, and it is held in tanks prior to disoharge Into ths sea. Tha effluent is monitored both chemically and biol ogically, using marine organisms, before It is discharged. The suggestion is thus quite unfounded. "What," asked one national newspaper, "is the nystorious red froth in the sea beneath Nanoekuke1!' These red waters, seen beneath Nanoekuke, at Qodrevy and elsewhere on the north Cornish coast, are caused by water running from ths adits of ths tin mines after rain. The phenomenon 1b well known to Cornishmen and the Red River, whioh discharges into St. Ivee Bay about a mile south of Qodrevy Point, has rsoeived its name from this. MQIkS 0999 7^ Reports of shoals of dead flah were oiroulatod. These all appear to relate to a ehoal of young pilchard, found ashore just to the west of Pendens by the keeper of the Pendene light-house on 29 October. These fish were examined by the Dietriot Inspeotor of fisheries at Newlyn, who sent speci mens to the MAff laboratory at Burnham-on-Crouoh, These were analysed for organoohlorlne oompounds, inoludlng PCBs, but no significant oonoentrations were found. It wss oonoluded that this shoal had stranded and subsequently dried out. A report of undersized pollack being oaught suffering from lesions desoribed as 'burns', both internal and external, has also been widely circu lated. The Inspeotor of fisheries oould not substantiate this report and no specimens were found. Cod and other gadoid fishes like pollack ere not infrequently found suffering from ulcerative lesions. In the oouree of the whole seal investigation only three dead eaa birds were found, and although birds were not especially looked for, this eeemn a very low figure for the time of the year. The lack of reports of dead birds in tha area auggaata there was no gross environmental pollution. Later obee rvatione at aaa To obeok whether the mortality at Cornwall in 1969 approaohed totality, a fishing vessel was ohartered on 11 Deoember to look for surviving pups at known brasdlng localities (figure 2) , The Carrack rooks, about 3 miles west of St. Ives, were first visited. This is a regular hauling plaoe for drey seals in the summer, but is not a breeding sits. No seals, either adult or pup, were seen at the Carracka but a very heavy ground swell whloh broke over the landing places would liave made it impossible for the seals to haul out. At the eastern limit of St. Ives Bay a young seal wno seen in tho water about 100 yards to the north of fiBhlng Cove; although stained with fuel-oil and rather thin about the neck it was not obviously siok. Another young seal was seen swimming vigorously in the surf to the weBt of Hell's Mouth. At Crane Island a young seal was seen close to the rocks, and another was seen off Samphire Island and two more sightings were made at Ralph's Cupboard. It is possible that these were of the same animal. Another young seal was seen Just to the west of Gull Rook. At dull Rook the tide forms an eddy where flotsam and tha bodies of dead animals aooumulate, aooording to fishermen with looal knowledge. No dead seal* were seen here, but two oiled guillemots were picked out of the sea. The sighting of six or more, probably seven, young seals off tha coast between Oodrevy Point and Portreath indioatee a fair survival of pups, on the baale of summer sightings of adults. Only one of the animals Been (the first sighted) did not appear to be in a perfeotly healthy oondltion, but son* further mortality of young might be expected in the course of the winter. No adult seals were seen during the trip; they were probably lying up in tho oaves MONS 099973 Plsousslon The primary oause of death of the seal pupa found on the Cornish ooaet Mae etarvatlon, thought to have been caused by the pups becoming separated from their mothers before' normal weaning time. The lactation period in drey seals is very short,lasting Issb than 3 weeks. The mother then deserts her pup which fasts and loses weight, before beginn ing to fend for itself. While it suckles the pup puts on weight at an astonishing rate, as muoh as 5.1 lbs/day being recorded (Coulson A Hiokling, 1964) though probably around 3-4 lbs/day is more usual. The link between the pup and its mother, its only souroe of food for the first three weeks of its life, is a delloate one and should it be broken early the pup's ohancea of survival are greatly deorsased. It is believed that a pup whioh has not reaohed a weight of around 65 lbs by its last milk feed is unlikely to survive the winter following its birth. Cow seals are known to lose oontaot with their pups as a result of bad weather or disturbance through orowding effeots or human interference. Crowding does not neoessarlly involve large numbers of seals; even a emll number of seals in a confined spaoe may oonstitute a orowd and disturbance to normal behaviour may follow, so that mortality through cows losing oontaot with their offspring is by far the commonest oause of pup death on drey seal breeding grounds. Starveling pups wander about trying to feed indiBoriminately from oows, or even bulls and other pups, and are frequently savagely bitten. Infeotlon of these wounds may 00cur as tjie pup's oonditlon falls and eventually death may result through septioaemia. The localities on the North Cornish ooast where Beals are found are all expoeed to northerly or westerly weather and most, if not all, the pups pro duced* in this area are born in the sea-oaves. Although the oaves offer some proteotion from the weather, the spaoe inside may be limited, particularly at high tide, and orowding of the type mentioned above may occur when even only half a dosen aeale uee a oave. A pup whioh strays outside its oave may well have great difficulty in finding its way baok again, particularly if the entranoe to the oave is beneath the water. It is probably the laok of good breeding sites whioh has limited the Orey seal population in Cornwall. Cray seals oocur most abundantly where the breeding females have sooees to sheltered beaohes or low grasslands behind a beaoh. By far the largest oonoentratlon of Orey seals in the South-west la that oentered on ths tip of Pembrokeshire, from Strumble Head to Caldey Island. This area, together with part of the Cardiganshire ooast, supports a population of about 300 pups, of whioh rather more than half are born on the islands of Ramsey and Skomer. About 200 Orey seals live on the Scilly Isles, mainly on ths rooky islets to the west of tho inhabited inlands and about 60 pups are produoed eaoh year. The numbers inhabiting Cornwall are less certain. Ths seals are considerably mors dispersed than at either tho Solllies or Pembroke and it eaerns likely that their numbers are added to in the Bummer by animals from the Pembrokeshire colonies. However, a figure of 200-250 seals for the Cornish ooast from Hartland Point round land's End to the Lizard seems reason able. Suoh a population would produoe about 60-75 pups eaoh year. MUNS 099974 Aa It wee oonoluded that about 40 pupa were reliably reported dead, and there were probably some dead animala which were not found (though it la thought that theae were vary few) thia would represent a high mortality if all the pupa oame from the Cornish stook. Orey eenla ore long-lived animala, life spans of up to 40 years being recorded. They have few predators other than man and the adult mortality rate, in the absence of human interferenoe, is thua very low. High juvenile mortality rates, on the other hud, are the rule at Cray seal breeding colonies. On the basis of existing life table data (Hewer 1964) it has bean assumed that on average 60)1 of all pups die in their first year, mostly soon after birth and weaning. There la, of oourse, year to year variation and populations breed ing at the foot of oliffe are very liable to total mortality of the pupa in bad weathsr. A spell of heavy westerly weather is believed to have killed nearly all the pups bora at a breeding site under the cliffs of Honas Hill in Shetland in 1969. In Cornwall, seals are very little, if at all, molested by man. Killer whales, virtually the only seal predator in English waters, are rarely seen off Cornish coasts. As the Cornish seal stocks do not show a rate of increase oomparable to that observed in the past quarter-century at other Cray seal colonies at, for example, the Fame Islands or the Orkneys, it is concluded that the juvenile mortality'rates in Cornwall must, on average, be high. The prob able reason for this is the laok of suitable breeding siteB on the inhospitable Cornish ooast. There is a possibility that not all the pups found dead originated from Cornwall, and the muoh larger Pembrokeshire population seems a likely source. Many young seals in Pembrokeshire were marked between 1992 and 1969 by the West Hales Naturalists' Trust and of the 62 marked animals recovered outside the marking area 20 have been recovered on the South-west Peninsula 1 one from the Scilly Isles, 15 from Cornwall and 4 from Devon. Of the 29 animals marked in I969 one has already been recovered from Cornwall. Table IV shows the lnoidenoe of winds of over 20 knots (corresponding to slightly more than Foroe 6 on the Beaufort scale) as reoorded at Milford Haven and St. Mawgan in September, October and November 19^9* Hinds of this speed oould oreate sea oondltlons bad enough to oause some pups in unfavourable sit uations to baoomo separated from their mothers. Between 7 and 9 November strong winds blew from between west and north (Table V) with speeds of up to 41 knots. All but 7 of the 40 reports of dead and dying pups follow this period of bad weather, so it seem likely that some of the animals reported could have been driven by the wind from Pembrokeshire to the Cornish ooast. It may be noted here that there was no similar reported mortality of seals from the Pembrokeshire ooast. Only two sickly pups had been noted at Dale Fort Field Centre by 10 Deoember and a representative of the Heat Halos Naturalists' Trust oonsiders that there are only five reliable records of dead or dying pupa, four from around Nanorbier and one from Tenby (Fig. l). It is highly likely ' that other deaths ooourrsd which were not reported but it is certain that there was no exceptional mortality in Pembrokeshire. MONS 099975 Smngary and Conclusion . About 40 reports of dsad or dying Orsy seal pups on the Cornish coast between Newquay and Fowey wars reoeivad In the autumn of 1969. Eleven of the dead seals were examined, of whioh 9 were subjects of full post-mortems. The oause of death was determined to be starvation) no evidenoe was found of an epldemio. Four adult seals seen at the Lizard at the end of November had lesions on their neoks. These lesions are believed to be the result of wounds, reoeived in fighting during the breeding season, becoming infected. Analyses of tissue samples of the dead Seals chow that the Cornish seal stocks, like those from elsewhere in the British Isles, are contuminated with organoohlorlne residues. The level of pentioido (DDT and dinldrin) contamination is relatively low but PCB contamination is relatively high, though muoh lower than in seals from East Anglia. The oonoentration of lead and arsenio in the Cornish seal pups is of the same order as that found in other mamalB. Mercury levels are higher. The seal pups whioh were found dead or dying had become separated from their mothers before the normal weaning time which is about three weeks after birth, and had been insufficiently developed to start feeding for them- eelveo. The separation was probably oaused either by disturbance or bad weather. Healthy pups were still to be found on the Cornish coast after the last of the reports was rsosivsd. ' Some of the pups reported from Cornwall may have originated from Pembrokeshire. A spell of high winds in early November might have caused pups to drift from Pembrokeshire to Cornwall. It is oonoluded that the deaths ware part of the normal juvenile mortality of the seals, always likely to be high In Cornwall, and that extraneous faotors such aa epldemios or pollution, ware not involved. W. Nigel Bonner Seals Research Offlosr Seals Research Unit Lowestoft. HONS 099976 labia I Summary of post-mortem reports on ten Gray seal duds Hof.No. Duto examined Sex Weight Diagnosis Organisms cultured 6822 27.10.69 F. lungs only Pneumonia 6087 27.10.69 M. 30 lbs. Septicaemia 7397 19.11.69 F. 12 lbs. Starvation 7620 28.11.69 F. (65 lbs) Septicaemia) some degree of starva tion 7634 29.11.69 - 25 lbs. Starvation (pneumonia) 7717 3.12.69 F. 22 lbs. Starvation 7789 7843 8.12.69 9.12.69 F. 42 lbs. Asphyxia F. 22 lbs. Starvation 7847 9.12.69 M. 35 lbs. Starvation 7052 9.12.69 U. 33 lbs. Starvation * eetimatedwjight Pasturella omltooida Pasturella multocida Esohoriohia coli - Escherichia coli - Fasteurella hasmolytlca Escherichia coli Streptococci Escherichia coli Proteus sp Escherichia coli Streptococci '- MQNS 099977 Tissue Cteigin fist content per cant Liver Cornish (fortham (well nour ished) northern (starving) 5-2 9-Q 7.6 Concentration in tissue, ppa wet weight Dieldrin ms THE IDT Total insecti cide organo chlorine PCS 0.08 1.9 o.3i 0.22 ` 2.51 46 0.07 0.07 0.5 0.09 0.5 1.0 0.15 0.9 1.16- 3.7 2.12 6.2 Cornish 16.7 0.25 6.7 0.69 3.7 11.34 160 Blabber Horthem (well nour ished) Northern (starring) 86.2 0.38 4.7 0.66 4.4 10.14 73-3 0.57 9-5 1.16 7.4 18.63 Table II Synopsis of concentrations of organochlorine caapoonds in seal tisane. (Tor full detailsy see Appendix). 3448 MONS 099978 TABLE III Concentrations of Arsenic, Load & Mercury in Seal tissues, expressed as miorograms per gram dry weight of tissue. (Analyses by S.E. Allen, Merlowood Research Station, Mature Conservancy. Grange-over-Sands, Lancashire) Concentration. dry weight Specimen No. (7843 ( 7847 | > 7852 ft ) J] 7620 3 [ 7634 | ( 7789 Sj (1) ( H06J ( > 11066 J5( II067 Si S> H064 JS} jjl 11065 Tissue Liver II Liver Kidney Liver it n Arsenio 20 54 3 15 8 1 10 29 Lead i <i i <i 5 4 3 2 Mercury 5 5 13 12 ' 8 9 7 11 Liver Kidney Liver Kidney Liver Kidney Liver Kidney Liver Kidney 17 42 <l l 3-5 3-5 20 <1 15 <1 2.6 3 4-9 5 3-5 6 2.2 <0.5 0.6 4 1.4 5 4.1 1 2.1 6 4-3 3 1.4 3 i........... . MOMS 099979 Table IV Number of hours In the month with recorded windspeeds of 20 knots or over at St. Hawgan and Milford Haven. (Bata from Meteorological Office) St. Uawgan Milford Haven September 3 30 October 31 20 November 171 78 Table V Average wind speed and direction for three days in November) 19^9. at St. Kawgan and Milford Haven. (Data from Meteorologloal Office) St.Mangan Speed Direction Milford Haven* Speed Direction 7 19.3 343 12.0 330 November t e 24.7 2ea 15.8 286 9 20.2 272 17.9 271 knots decrees knots decrees MONS 099980 List of Figures Flg.l. Map to show distribution of reports of dead and dying seals on the Cornish coast. Five similar reports from Pembrokeshire are also shown. Fig.2. The coast searohed for young seals. MUNS 099981 References Couloon J.C. 4 Hiokling G. 1964* Tho breeding biology of the Gray seal, Halichoerua arypua (Fab.) on the Foma Inlands, Northumberland. J.Anim.Eool.^ i 485-512 Davies J.L. 1957' The geography of the Grey seal. J.Mammal. J8 (3) t 297-310 Hewer H.Ii. I9S4. The Determination of age, sexual maturity, longevity and a life-table in the Grey seal (Halichoerua SMl) ,, ,, Proo. zool. Soe. bond. 142 (4) < 593-624- Johnston D.G. 4 Ridgway 3.H. 1969* Parasitism in some marine mammale. J. Amer. vet. med. Assoo. 155 IO64-IO72 Merchant I.A. 4 Packer R.A. 1967* Veterinary Bacteriology 4 Virology. Iowa State University Press. Amer. Iowa. 7th ed. 1967. A + 752 PP- MUNS 099982 Concentrations of organochlori.no compounds in seal tissues, expressed as parte per million, wet weight of tiaauo. * (Analyses by A.V. Holden, Freshwater Fisheries Laboratory, . Department of Agriculture 4> Fisheries for Scotland, Pitlochry, Perthshire.) Speoimen No. Tiesue Fat Content per oent Concentration in tioeue, p. p.m. wet weight Dieldrin DDE TDE DDT PCB ( 7843 ( 7047 7052 ( 7'*>20 g.) 7634 .1 M ' r*t AV verage 8 1 7843 ) 7847 ) 7852 Average Liver It |l II II Blubber II II 4-3 2.3 4.5 4.1 11.1 2.6 6.7 5-2 37.5 8.2 4*4 16.7 < 0.01 0.07 o.u 0.05 0.15 0.04 o.u 0.08 O.44 0.23 0.08 0.25 0.9 0.15 1.8 1.3 1.2 O.57 1.0 < 0.04 1.6 < 0.02 1.0 < 0.02 5.1 < 0.04 1.9 0.31 8.7 1.1 8.1 0.69 3.2 0.27 6.7 O.69 0.4 0.1 0.8 < 0,08 < 0.04 < 0.04 <0.08 0,22 4.5 5-0 1-7 3.7 17 36 77 31 43 26 90 46 173 187 118 160 ( H063 ) H066 ( H067 Liver II II Average (UO63 ) hg66 3 ( H067 9J (/Average 1 \ 8O64 3 ( HO65 0r (Average Blubber If If Liver 11 \ HO64 > HO65 Blubber If /Average 10.0 9.2 7.9 9.0 84.7 87.4 86.6 86.2 7-4 7.8 7.6 80.4 67.1 73.8 0.04 0.7 0.09 0.7 5-2 ) 0.11 0.5 0.09 0.4 3.8 0.07 0.3 0.09 0.3 2.2) 0.07 0.5 0.09 0.5 0.37 6.0 0.06 6.5 O.58 4.9 0.65 4.1 0.20 3.3 O.46 2.6 0.33 4-7 0.66 4.4 0.05 0.7 0.09 0.6 0.08 1.3 0.21 1.2 44 1 1 34 M 25 3 )m 34) 3.9) 8.4) 0.07 1.0 0.15 0.9 6.2 j. 0.54 10.3 1.17 7.6 0.59 0.6 1.15 7.2 5 )!! 46 0.57 9.5 1.16 7.4 ` 40 j MQNS 099983 .RjT. t& sAe-W feparfk O^ dul * setdi <n\ fee Corvv\Ck Coat. five SjVii'Uv -Te|>o*t J.w>~v Qmfcvnleilwve, *ve. a-fce> S fcev^v. 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