Publication Abstract

Exploring the use of caged Nucella lapillus to monitor changes to TBT hotspot areas: A trial in the River Tyne estuary (UK)

A.J. Smith, J.E Thain and J. Barry 

The development of the condition known as imposex in female neogastropod molluscs is one of several well-documented affects of tributyltin (TBT) exposure. This paper looks at caged, previously unaffected populations exposed to ambient levels at several points along the River Tyne, a UK estuary known to have high TBT levels. Caged populations of dogwhelks were suspended in and around the estuary for six months in areas of moving water. The aim was to observe the induction of imposex caused by interaction with TBT in the water column and from the ingestion of mussels feeding in the same water column. After six months imposex levels in the whelks where calculated using the vas deferens sequence index (VDSI) and the relative penis size index (RPSI). Percentage occurrence was also recorded for each site. Tin levels in the whelks and mussels were analysed for each site. Sites within the estuary showed strong levels of induction, with low induction North of the mouth, and very low or no induction in the south site and the controls. This matched the pattern of TBT levels found in the dogwhelk and mussel tissues. The results and site locations are discussed in reference to the imposex and TBT levels found. Further monitoring work is suggested to observe the effects of new legislation.

Reference:

A.J. Smith, J.E Thain and J. Barry  (2006) Exploring the use of caged Nucella lapillus to monitor changes to TBT hotspot areas: A trial in the River Tyne estuary (UK). Marine Environmental Research, 62(2): 149-163