Predictors of pesticide concentrations in freshwater trout - The role of life history.
Concentrations of halogenated pesticides in freshwater fish can be affected by age, size, trophic position, and exposure history. Exposure history may vary for individual fish caught at a single location due to different life histories, e.g. they may have hatched in different tributaries before migrating to a specific lake. We evaluated correlations of pesticide concentrations in freshwater brown trout (Salmo trutta) from the Clutha River, New Zealand, with potential predictors including capture site, age, length, trophic level, and life history. Life history was determined from otolith (fish ear bone) strontium isotope signatures, which vary among tributaries in the region of our study. Variability in pesticide concentrations between individual fish was not well explained by capture site, age, length, or trophic level. However, hexachlorobenzene (HCB) and chlorpyrifos concentrations were distinct in lake-based trout with different life histories. Additionally, one of the riverine life histories was associated with relatively high concentrations of total endosulfans. Linear models that included all potential predictor variables were evaluated and the resulting best models for HCB, chlorpyrifos, and total endosulfans included life history. These findings show that in cases where otolith isotope signatures vary geographically, they can be used to help explain contaminant concentration variations in fish caught from a single location.
Department of Chemistry, University of Otago, Dunedin 9016, New Zealand.
Rachel C
RC
Scholes
Department of Chemistry, University of Otago, Dunedin 9016, New Zealand. Electronic address: khageman@chemistry.otago.ac.nz.
Kimberly J
KJ
Hageman
Department of Zoology, University of Otago, Dunedin 9016, New Zealand.
Gerard P
GP
Closs
Department of Chemistry, University of Otago, Dunedin 9016, New Zealand; Centre for Trace Element Analysis, University of Otago, Dunedin 9016, New Zealand.
Claudine H
CH
Stirling
Department of Chemistry, University of Otago, Dunedin 9016, New Zealand; Centre for Trace Element Analysis, University of Otago, Dunedin 9016, New Zealand.
Malcolm R
MR
Reid
Department of Zoology, University of Otago, Dunedin 9016, New Zealand; Cawthron Institute, Nelson 7010, New Zealand.
Rasmus
R
Gabrielsson
Department of Zoology, University of Otago, Dunedin 9016, New Zealand.
Jason M
JM
Augspurger
D000818:Animals; D004726:Endosulfan / Q000032:analysis; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry; D006581:Hexachlorobenzene / Q000032:analysis; D008018:Life Cycle Stages; D009520:New Zealand; D010037:Otolithic Membrane / Q000737:chemistry; D010575:Pesticides / Q000032:analysis* / Q000378:metabolism; D045483:Rivers / Q000737:chemistry; D013325:Strontium Isotopes / Q000032:analysis; D014337:Trout / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
D010575:Pesticides; D013325:Strontium Isotopes; D014874:Water Pollutants, Chemical; D006581:Hexachlorobenzene; D004726:Endosulfan
Chlorpyrifos; Endosulfan; Fish migration; Hexachlorobenzene; Isotopes; Strontium