1986-1989 England, Wales and Scotland report on TBT contamination of Nucella lapillus dataset https://portal.medin.org.uk/portal/start.php?tpc=010_d212fa5f6b87e907ce15b84b8cf517f8 Nucella lapillis presence records from around Great Britain. Presence records part of a more extensive set of surveys investigating TBT contamination of Nucella lapillus. Three reports have been compiled to date using data collected from the autumn of 1986 to summer 1989. The first interim report (Spence et al., 1987) was an extensive essentially qualitative survey to identify at what sites dogwhelks occur, areas of absence and low density adjacent to boating activity and population structure of those dogwhelks present. In the second report (Hayter, 1988) significant changes in population structure were found at a number of sites but changes in protocol, timing and surveyors precluded accurate assessment of recovery following legislation to restrict the use of TBT. The third report (Spence et al., 1990) was essentially the same as the second, building up a database and allowing comparisons over a three year period. 19901231 19891231