Persistent Pollutants in Audouins Gull Larus audouinii) in the WesternMediterranean A Case-study with Wide Implications

byM F I J BIJLEVELD PhD (Amsterdam Free University)

Programme Officer IUCN 1110 Morges Switzerland

P GOELDLIN PhD (Lausanne)

Zoological Museum Lausanne Switzerland

amp

J MAYOL

Grupo Ornitologia Balear Palma de Mallorca Spain

INTRODUCTION

The world population of the rare and specializedAudouins Gull Larus audouinii) is restricted to theMediterranean region (Voous 1960) and is now esti-mated to number only about 2000 pairs of which thewestern Mediterranean harbours some 80 Although anincrease appears to have occurred in the latter area inrecent years (Mayol 1978) the species is rightly includedin the IUCN Red Data Book (Figs 1 amp 2)

In 1978 a survey of the species was carried out in theframework of project No 1413 in the conservation pro-gramme of the International Union for Conservation of

Nature and Natural Resources (IUCN) the World Wild-life Fund (WWF) and the International Council for BirdPreservation (ICBP) During this survey some eggs thathad not hatched were collected and their contents wereanalysed at the Cantonal Laboratory of the Canton deVaud Epalinges Switzerland The shells have been de-posited in the Zoological Museum Lausanne

METHODS

Three of the unhatched eggs of Audouins Gull werecollected in the southern Mediterranean region off the

Fig 1 Adult Audouin s Gulls (Larus audouinii) Total length (tip of bill to tail) 49 cm Photo Helmar Schenk

139

Environmental Conservation Vol 6 No 2 Summer 1979mdashcopy1979 The Foundation for Environmental ConservationmdashPrinted in Switzerlandhttpswwwcambridgeorgcoreterms httpsdoiorg101017S0376892900002642Downloaded from httpswwwcambridgeorgcore University of Basel Library on 11 Jul 2017 at 121501 subject to the Cambridge Core terms of use available at

140 Environmental Conservation

Fig 2 Flock of adult Audouins Gulls on an island off the coastof Morocco Photo Joan Mayol

Moroccan coast the other four being collected in the

northern Mediterraneanmdashin the Balearic Islands where

also were collected one unhatched egg each of the Medi-

terranean Herring Gull (Lams argentatus michahellis)

and the Black Vulture (Aegypiusmonachus) Only addled

eggs that had failed to hatch were taken and therefore

these do not constitute an unbiased sample

The qualitative and quantitative analyses of organo-

chlorine insecticide and polychlorobiphenyl residues

have been accomplished througha) Extraction from samples by employing the

method of Langlois etal (1964)

b) Clean-up of the extracts by absorptive chroma-

tography on a column of florisil and

c) Determination of the residues by gas chromato-

graphy on two columns of different polarities employing

electron capture detection

The determination of total mercury was carried out

by flameless atomic absorption spectrophotometry (cold-

vapour system)

RESULTS AND DISCUSSION

The results of the analyses are presented in Table I

Chemicals detected included mercury DDE (dichloro-

phenyl-dichloroethylene) PCBs (polychlorinated bi-

phenyls) HCB (hexachlorobenzene) dieldrin and HE

(heptachlor-epoxide) On average levels were lowest for

dieldrin heptachlor-epoxide and hexachlorobenzene

The difference between average levels of DDE PCBs

and mercury in Audouins Gulls in the northern and

southern parts of the western Mediterranean is striking

DDE levels averaged from 194 ppm in the south to

367 ppm in the north

A strong correlation was found between the amount

of DDE (metabolite of DDT) in eggs with reproductive

success or decline of the Brown Pelican (Pelecanus

occidentalis) in South Carolina (Blus et al 1974)

Reproductive success was normal in those nests in which

sample eggs contained 25 ppm DDE or less while in

those with eggs exceeding that level no downy young

were produced (Ibid) Similar relationships were found

in Ospreys (Pandion haliaetus) in Connecticut at average

levels of 89 ppm DDE in sample eggs whereas Ospreys

in Maryland hatched normally at an average level of

24 ppm DDE in sample eggs (Wiemeyer etal 1975)

Lincer (1975) came to similar conclusions with regard to

the American Kestrel (Falco sparverius) Koeman et al

(1972) concluded that DDE was most likely to be the

major cause of the lack of reproductive success in Sea

Eagles (Haliaetus albicilla) in Schleswig-Holstein Fed-

eral Republic of Germany where an average of 1012

ppm DDE has been found in eggs that did not hatch

The average levels of pollutants found in the southern

part of the western Mediterranean region still seem to

fall within the range where normal reproduction can be

expected (cf Figs 3 amp 4)Although the failures of hatching may have resulted

from disturbance or some other cause the average level

foundmdashespecially in the north of the western Mediter-

ranean where maximum levels reach 415 ppm and 544

ppmmdashgive reason for concern as they approach or have

already reached the level where only diminished repro-

duction can take place In this context the fact that two

of the sample eggs from the northern Mediterranean con-

tained embryos may have some significance (cf Blus

etal 1974)

Average levels of PCBs also appear to be much higher

in the northern than in the southern part of the western

Fig 3 Nest and eggs of Audouins Gull (Larus audouinii) on a

Balearic island Eggs approx 62 X 43 mm Photo Joan Mayol

Fig 4 Audouins Gulls (Larus audouinii) in first-year plumage

These specimens are not yet fully grown Photo Xese Moll

httpswwwcambridgeorgcoreterms httpsdoiorg101017S0376892900002642Downloaded from httpswwwcambridgeorgcore University of Basel Library on 11 Jul 2017 at 121501 subject to the Cambridge Core terms of use available at

Bijleveld et al Persistent Pollutants in Audouin s Gull (Larus audouinii) in the Western Mediterranean 141

TABLE I Residues of Organochlorine Pesticides PCBs and Mercury in Eggs of Audouins Gull Herring Gull andBlack Vulture 1978

Species Collection area Residue concentration ppm (net-weight)

DDE Dieldrin HE HCB PCB Hg

Remarks

Larus audouiniiLarus audouiniiLarus audouinii

Chafarinas IslandsChafarinas IslandsChafarinas IslandsAverage

102195284

004600780050

tr0013ndt

194 0058

002800340027

0030

314242

070063095

382 076

Larus audouiniiLarus audouiniiLarus audouiniiLarus audouinii

Balearic IslandsBalearic IslandsBalearic IslandsBalearic Islands

220544290415

0104013801300120

0031nd+

00290023

0055008501580080

128206160176

087100139122

tr = trace I nd = not determined

embryonated

embryonated

Larus argentatus subsp

Aegypius monachus

michahellis

Average

Balearic Islands

Balearic Islands

367

355

020

0123

0062

nd+

0021

0007

0008

009

0053

0012

1675

110

04

I

1

0

12

20

15

Mediterranean being 1675 ppm and 382 ppm respec-tively In general however there are no indications asyet that PCBs are involved in any reduction of reproduc-tion in birds The levels found are relatively low in com-parison with some of those found for example in NorthGerman Sea Eagles (Koeman et al 1972 Blus et al1974)

Dieldrin levels ranging from averages of 0058 ppm inthe south to 0123 ppm in the north can be regarded astoo low to influence reproductive success Blus et al(1974) found that reproduction in the Brown Pelicanwas still normal in eggs containing lt054 ppm of dieldrin

As could be expected lower levels of mercury (average076 ppm) were found in the south of the western Medi-terranean than in the northern portion (112 ppm)However these levels are not likely to influence repro-ductive success (J H Koeman 1979 pers comm)

The levels of residues of organochlorine pesticidesfound in an egg of the Mediterranean Herring Gull in theBalearic Islands equal the average level of DDE found inthe eggs of Audouins Gull whilst levels of dieldrinHE HCB and PCBs are considerably lowermdasha fact thatmay be related to Audouins Gull being more exclusivelya fish-eating species

The analysis of the contents of an unhatched egg ofthe Black Vulture from the Balearic Islands revealed ex-tremely low levels of all organochlorine compounds andof mercury The hatching failure of this egg is thereforelikely to be due to other factors The extreme differencesfound between levels in this terrestrial species and thetwo marine species all of them placed at the end of food-chains well illustrate the contamination of the marineenvironment

CONCLUSION

The levels of DDE found in the eggs of AudouinsGull especially in the western Mediterranean give reason

for concern about the reproductive success of the specieswhich could be impeded by further contamination ofthis marine environment by DDT These findingsmdashthefirst that are known to us on marine birds eggs in theMediterraneanmdashcomplement similar findings of hifhlevels of organochlorine compounds in a wide variety ofspecies elsewhere in the Mediterranean (CIESM [Com-mission internationale pour lexploration scientifique dela Mediterranee] 1979)

ACKNOWLEDGEMENTS

We are indebted to Drs A Etournaud and A Ramuzof the Cantonal Laboratory of the Canton de Vaud forcarrying out the analyses and to the World WildlifeFund Switzerland for making this financially possibleTo Professor Dr J H Koeman of the Agricultural Uni-versity Wageningen Netherlands and to Dr P HunkelerIUCN Morges Switzerland we are grateful for theirhelpful advice given on reading an earlier draft of themanuscript

SUMMARY

The possibility of persistent pollutants playing anadverse role in the reproductive success of AudouinsGull in the western Mediterranean was examined throughchemical analyses of 7 eggs of this species that did nothatch Residues of organochlorine compounds and mer-cury were found

The conclusion has been reached that a further in-crease of present levels of DDE may well lead to a declineof the reproductive success of the species in the westernMediterranean especially in the northern part Theseobservations although limited could have implicationsfor further species as is already indicated by other workcited

httpswwwcambridgeorgcoreterms httpsdoiorg101017S0376892900002642Downloaded from httpswwwcambridgeorgcore University of Basel Library on 11 Jul 2017 at 121501 subject to the Cambridge Core terms of use available at

142 Environmental Conservation

REFERENCES

BLUS L J NEELY B S BELISLE A A amp PROUTY R M(1974) Organochlorine residues in Brown Pelican eggsRelation to reproductive success Environ Pollut 7 pp81-91

CIESM (1979) IVesJournees dEtude sur les Pollutions Marinesen Mediterranee Workshop on Pollution of the Mediter-ranean Antalya 24-27 November 1978 Commission Inter-nationale pour lexploration scientifique de la Mediter-ranee Monaco 681 pp

KOEMAN J H HADDERINGH R H amp BIJLEVELD M F IJ (1972) Persistant pollutants in the White-tailed Eagle(Haliaetus albicilla) in the Federal Republic of GermanyBiol Conser 4 (5) pp 373-7

LANGLOIS B E STEMPAR A R ampLISTA B J (1964)Rapid clean-up of dairy products for analysis of chlorinatedinsecticide residue by electron capture gas chromatographyJ Agr Food Chem 12 p 243

LINCER J L (1975) DDE-induced eggshell-thinning in theAmerican Kestrel A comparison of the field situation andlaboratory results Appl Ecol 12 pp 781-93

MAYOL J (1978) Las Colonias de Gaviota de Audouin en elMediterraneo occidental en 1978 Stencilled report IUCN1110 Morges Switzerland 32 pp

VOOUS K H (1960) Atlas of European Birds Nelson LondonUK 284 pp illustr

WIEMEYER S N SPITZER P R KRANTZ W C LAMONTT G amp CROMARTIE E (1975) Effects of environmentalpollutants on Connecticut and Maryland Ospreys J WildManage 39 (1) pp 124-39

International Effort to Study Causes of Monsoons

The largest scientific venture ever undertaken jointlybetween the United States and South-east Asia has beenlaunched as part of a year-long effort to determine whatcauses the erratic behaviour of monsoons that are apt todevastate large areas of the world One goal of the inter-national project is to hasten the day when scientists willbe able to forecast monsoons accuratelymdasha capabilitywhich has been described as among mankinds most im-portant single predictions

The project called MONEX for monsoon experimentwas started on 1 December 1978 in Kuala Lumpur thecapital of Malaysia The US portion of the project isbeing coordinated by the National Science Foundation(NSF) and is considered a major expression of goodwillbetween the US and the South-east Asian countries wherethe winter phase of MONEX is being concentrated OtherUS agencies taking part in the project are the NationalOceanic and Atmospheric Administration (NOAA) andthe National Aeronautics and Space Administration(NASA)

Monsoons which vary in time and intensity from yearto year can bring life-giving rains or cause devastatingdroughts in South-east Asia and West Africa They arethe basis for the rich agriculture of this vast region and amajor factor in the feeding of hundreds of millions ofpeople who inhabit the area The improved forecastswhich may result from this project could be of specialbenefit to farmers and fishermen enabling the former tomake suitable decisions on when to plant their seeds orto harvest their crops (eg avoiding inclement weatherconditions that could affect yields) while the latterwould be able to plan their voyages on the open seas bullwith a minimum of risks of encountering bad storms

The behaviour of large-scale Asiatic monsoons islinked to global circulations which bring weather andpossibly weather anomalies to the United States A betterknowledge of the Asian monsoon as a major regionalenergy source is essential to an improved understandingof global weather and climate Extended forecasts overall areas of the world are probably not possible withoutdetailed knowledge of the weather in the tropics and itswide-ranging effects In addition to the United Statesand Malaysia almost every country in South-east Asia isparticipating in the project

Because of the natural division of the monsoon into awinter and a summer phase and because of the regionaldistinctions in the monsoon between the eastern andWestern regions of Asia two separate efforts are re-quiredmdasha winter MONEX and a summer MONEX Thesummer phase is scheduled to start on 1 May 1979 andto continue for four months with its activities centredat New Delhi India Both efforts are designed to obtaina more comprehensive understanding of the regional andseasonal fluctuations of the Asian monsoon and of itseffect on global atmospheric circulation than has hithertobeen available

For these purposes ships and aircraft will gather datafrom an area of some 74 million square kilometres overthe Indian Ocean Arabian Sea the Bay of Bengal South-east Asia and the South China Sea In addition MONEXscientists will get data from two geostationary weathersatellites one of which is being provided earily in 1979over the Indian Ocean in a cooperative effort by theNSF NOAA and NASA while the other has alreadybeen made operational to the south of Japan by theJapanese

MONEX is one of three regional experiments organizedwithin the framework of the Global Weather Experimentthe other two are the West African Monsoon Experimentand the Polar Experiment The Global Weather Experi-ment in which more than 140 nations are participatingis part of the Global Atmospheric Research Programmea joint effort of the World Meteorological Organizationand the International Council of Scientific Unions TheGlobal Weather Experiment is a year-long internationalprogramme of research and data-gathering whose ultimategoal is to make possible longer-range weather predictionsand to study the underlying causes of climate changes

Ralph KazarianNational Science Foundation1800 G StreetWashingtonDC 20550USA

A referee points out the importance here of policy on acqui-sition storage and importmdashEd

httpswwwcambridgeorgcoreterms httpsdoiorg101017S0376892900002642Downloaded from httpswwwcambridgeorgcore University of Basel Library on 11 Jul 2017 at 121501 subject to the Cambridge Core terms of use available at