Organotin and Imposex in the Littoral Zone in the Faroe Islands: Organotin og imposex í strandarøkinum í Føroyum

Abstract

Organotin may be found as a component in some of the coatings that are intended for ships. The effect of organotin is to prevent growth on the submerged part of the hull, and thus keep the surface smooth. A ship with a smooth 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 scraping 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 gastropods, especially the dogwhelk Nucella lapillus, is particularly sensitive to the organotin species tributyltin, TBT. The response of the dogwhelk to TBT is the development of male sexual characteristics in females, a state which is referred to as "imposex". In the most pronounced stage, imposex renders the female unable to reproduce.

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 imposex phenomenon in dogwhelks collected at seven locations on the Faroes Islands is shown.