title: Evaluation of toxicity in tributaries of the Mersey estuary using the isopod Asellus aquaticus (L.).
abstract: Increasing numbers of industrial, agricultural and natural chemicals are present in sewage effluent and are known to elicit toxic effects in laboratory exposures, but little is known of their combined sub-lethal effect in the field. In this study, a combination of esterase activity and ventilation rate assays was performed to determine the neurological and physiological function of the freshwater crustacean Asellus aquaticus (L.) at sites above and below a sewage treatment works (STW). Cholinesterase and carboxylesterase activities were significantly inhibited (n=8, P<0.05) and ventilation rates increased (n=8, P=0.0001) in A. aquaticus at STW sites compared to those from reference sites, indicating a decrease in neurological and physiological function. The ecological relevance of these findings for the population dynamics of the organisms in the field is discussed.
authors.affiliation: School of Biological Sciences (PERC), University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK. a.oneill@plymouth.ac.uk
authors.forename: A J
authors.initials: AJ
authors.lastname: O'Neill
authors.forename: T S
authors.initials: TS
authors.lastname: Galloway
authors.forename: M A
authors.initials: MA
authors.lastname: Browne
authors.forename: A
authors.initials: A
authors.lastname: Dissanayake
authors.forename: M H
authors.initials: MH
authors.lastname: Depledge
mesh_terms: D015415:Biomarkers; D043182:Carboxylesterase / Q000378:metabolism; D002802:Cholinesterases / Q000378:metabolism; D004739:England; D004784:Environmental Monitoring; D005618:Fresh Water / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D033321:Isopoda / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D010100:Oxygen / Q000032:analysis; D012722:Sewage / Q000032:analysis*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D012722:Sewage; D014874:Water Pollutants, Chemical; D043182:Carboxylesterase; D002802:Cholinesterases; D010100:Oxygen