Browne_2015_Environ.Pollut_203_208

Detecting impacts of organophosphorus biocides (OP) is facilitated by analysing "biomarkers" - biological responses to environmental insults. Understanding is hampered by studying biomarkers in isolation at different levels of biological response and limited work on ecologically-important species. We tested the relevance of esterases as biomarkers of OP-exposure in limpets (Patella vulgata), abundant prosobranchs that structure the assemblages on rocky shores through their grazing. We characterized esterases in haemolymph and tissue, and quantified their dose-dependent inhibition by chlorfenvinphos (0.1-3.0 mM) in vitro. To determine whether esterases are useful biomarkers we exposed limpets to chlorfenvinphos (0-10 mug L(-1)). Despite reduced tenacity (ability to stick to a surface) and haemocyte-viability, esterases remained unaffected. Tenacity was reduced by >50% at 5 mug L(-1) and by 95% at 10 mug L(-1), whilst haemocyte-viability was more sensitive with >40% reductions at concentrations of 0.5 mug L(-1) and above. We discuss results in relation to linking sub-lethal and ecological impacts at contaminated sites.