Gj. Nicholson et al., The value of imposex in the dogwhelk Nucella lapillus and the common whelkBuccinum undatum as indicators of TBT contamination, INVERTEBR R, 34(2-3), 1998, pp. 289-300
Measures of imposer in the Dogwhelk N. lapillus and the Common Whelk B. und
atum were used, together with analyses of butyltins in tissue and sediment
samples, to assess current levels of TBT contamination in four sealochs, wh
ich are subject to different kinds and intensities of boat use and fish far
ming. Imposer in N. lapillus is a specific response to TBT and some related
organotins and, as would be expected therefore, indices of; imposer correl
ated with concentrations of butyltins in tissues. Data from this species, a
nd sediments, indicate that TBT contamination in three of the sealochs (Loc
h Sween, Loch Crinan and Killary Harbour) is now low. It has decreased sign
ificantly in Loch Sween and Loch Crinan during the past decade. There were
higher levels of pollution in Sullom Vee, where oil tankers are a source of
TBT. This was reflected in measures of imposer and concentrations of butyl
tins in tissue samples but not of those in sediments, which were surprising
ly low. Imposer was recorded in most samples of B. undatum examined in this
study but it is not a useful indicator of butyltin contamination. The cond
ition was severe in some places where pollution was low and, conversely, ab
sent or poorly developed in others, where it was high. There was no correla
tion between the severity of imposer and tissue concentrations of butyltins
in this species.