Fróðskaparrit - 01.01.1998, Page 61

67
Organotin and Imposex in the Littoral Zone
in the Faroe Islands
Organotin og imposex í strandarøkinum í Føroyum
Norunn Følsvik1, Einar M. Brevik1, John Arthur Berge1 and Maria Dam2
1. Norwegian Institute for Water Research, Box 173, Kjelsás, N-0411 Oslo, Norway
2 Food- and Environmental Agency, Debesartrøð, FO-IOO Tórshavn, Faroe Islands,
Phone +298 31 53 00, Fax +298 31 0508, e-mail:mariadam@hfs.fo
Úrtak
Organotin kann vera í evnum, sum eru ætlað at klæða
skip við. Arinið av organotin er, at tað forðar fyri gróðri
á tí partinum av skrokkinum, sum er undir, so at yvir-
flatan verður verandi sløtt. Eitt skip við slættari y virflatu
glíður lættari gjøgnum sjógvin, og tað brúkar tí minni
brennievni til sigling. Sama ávirkan kundi verið fingin,
um botnurin á skipinum varð skavaður við hond, men
tað bæði tekur tíð og krevur arbeiði, og tí er tann evna-
frøðiliga loysnin framvegis vanlig í dag. Tfverri hevur
tað víst seg, at summar havgastropodir, serstakliga
purpurkúvingur Nucella lapillus, eru serliga viðbreknar
fyri organotinsløgunum tributylin, TBT. Purpur-
kúvingur verður ávirkaður av TBT á tann hátt, at kall-
ynseyðkenni mennast f kvenndýrunum, ein støða, sum
verður umtalað sum »imposex«. Á tí sjónskasta stignum
av imposex eru kvenndýrini ikki før fyri at fjølgast. Tað
hevur víst seg, at imposex er vanligt í heldur fjølbygdum
strandarsamfeløgum og eisini fram við siglingarleiðum
’ á landi. Hend greinin lýsir, hvørjum støði organotin-
sløgini eru á í strandarøkinum í Føroyum, og hvat árin
tey hava á tað. Urslitini av greiningunum av organotin-
sløgum í purpurkúvingi, Nucella lapillus, kræklingi,
Mytilus edulis, og í fliðu, Patella vulgata, verða løgd
fram. Ovumøgdin av fyribrigdinum imposex í purpur-
kúvingum, sum eru savnaðir á sjey støðum í Føroyum,
verður víst.
Abstracts
Organotin may be found as a component in some of the
coatings that are intended for ships. The effect of organ-
°tin is to prevent growth on the submerged part of the
■vall, and thus keep the surface smooth. A ship with a
moo,h surface slides more easily through the water and
therefore uses lesser amounts of fuel for propagation.
This same effect could be obtained with a manual scrap-
ing of the bottom of the vessel, but this takes both time
and labour, hence the chemical way is prevailing today.
Unfortunately it has appeared that certain marine gas-
tropods, especially the dogwhelk Nucella lapillus, is
particularly sensitive to the organotin species tributyltin,
TBT. The response of the dogwhelk to TBT is the de-
velopment of male sexual characteristics in females, a
state which is referred to as “imposex”. In the most pro-
nounced stage, imposex renders the female unable to re-
produce. Imposex has been found to be widespread in
the more densely populated coastal communities and
also along ship lanes offshore. The present paper
desribes the levels and effects of organotin species in the
littoral zone on the Faroe Islands. The results of the
analyses of organotin species in dogwhelk, Nucella
lapillus, common mussel, Mytilus edulis, and in limpets,
Patella vulgata, are given. The abundance of the impo-
sex phenomenon in dogwhelks collected at seven loca-
tions on the Faroes Islands is shown.
Summary
The use of organotin compounds as an-
tifouling agents, fungicides, insecticides
and bactericides has increased dramatically
over the last 30 years. They are considered
among the most toxic compounds intro-
duced to the marine environment, where
the main focus has been on the extremely
effective antifouling agent tributyltin
(TBT).
Unintended environmental effects from
tributyltin in antifouling paints were first
Fróðskaparrit 46. bók 1998: 67-80