|Spatial and temporal evolution of imposex in Nucella lapillus (L.) populations from North Wales|
de Carvalho Benta Santos Oliveira, I.M. (2007). Spatial and temporal evolution of imposex in Nucella lapillus (L.) populations from North Wales. MSc Thesis. Universidade de Aveiro. Departamento de Biologia: Aveiro. 113 pp.
|Available in|| Author |
VLIZ: Non-open access 240776
|Document type: Dissertation|
|Author|| || Top |
- de Carvalho Benta Santos Oliveira, I.M.
Imposex - superimposition of male characters onto prosobranch females - in the dogwhelk Nucella lapillus is a highly specific biological response to organotin exposure and has been used for monitoring TBT and TPT pollution throughout Atlantic coasts. A cause-effect relationship between TBT and imposex was already reported by many authors. However, recent field studies have suggested the hypothesis that there could be different sensitivities in the imposex response of dogwhelks from two different sites in Ria de Aveiro. In order to clarify this hypothesis, dogwhelks from both sites were exposed, at the laboratory, to a nominal concentration of 100ng TBT-Sn/L for 45 days. TBT caused the development of imposex in both groups of animals but no significant different responses were observed between them. These results support the concept of a geographical uniformity of dogwhelks’ imposex response to TBT pollution. Spatial and temporal evolution of imposex around North Wales was investigated through the assessment of N. lapillus imposex, between November and December of 2006 along North Wales’ coast (with respective organotin analysis of the dogwhelk female tissues) by the comparison of these data with data reported in similar previous studies of other authors. The effectiveness of the TBT restrictive measures in the UK were corroborated by the decreasing imposex values from 1987 to 2006.