title: Detection of temporal trends of α- and γ-chlordane in Lake Erie fish communities using dynamic linear modeling.
abstract: Dynamic linear modeling (DLM) analysis was performed to identify the long-term temporal trends of two toxic components of the technical chlordane pesticide, α- and γ-chlordane, in skinless-boneless muscle tissues of a number of sport fish species in Lake Erie. Our analysis considers the fish length as a covariate of the chlordane concentrations. The α-chlordane models for the coho salmon, channel catfish, rainbow trout, and common carp showed continuously decreasing trends during the entire 30+ year survey period (1976-2007). The γ-chlordane models demonstrated similar trends for the coho salmon, channel catfish, and common carp. These fish species had higher levels of α- and γ-chlordane in their muscle tissues. The α- and γ-chlordane levels in freshwater drum, smallmouth bass, walleye, white bass, whitefish, and yellow perch decreased until the mid-1980s and hovered at levels around the detection limits for the remaining period. The pesticide biotransformation process, the reduction of contaminant emissions to the environment, the feeding habits of the different fish species, and the food-web alterations induced by the introduction of aquatic invasive species are some of the hypotheses proposed to explain the observed temporal trends in different fish species in Lake Erie.
authors.affiliation: Ecological Modeling Laboratory, Department of Physical and Environmental Sciences, University of Toronto, Toronto, Ontario, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Ekram Azim
authors.forename: Michelle
authors.initials: M
authors.lastname: Letchumanan
authors.forename: Azzam
authors.initials: A
authors.lastname: Abu Rayash
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimoda
authors.forename: Satyendra P
authors.initials: SP
authors.lastname: Bhavsar
authors.forename: George B
authors.initials: GB
authors.lastname: Arhonditsis
mesh_terms: D000818:Animals; D002347:Carps / Q000378:metabolism; D002706:Chlordan / Q000032:analysis / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D005399:Fishes / Q000378:metabolism*; D005618:Fresh Water / Q000737:chemistry*; D007306:Insecticides / Q000032:analysis / Q000378:metabolism*; D058865:Introduced Species; D016014:Linear Models; D009132:Muscles / Q000378:metabolism; D010471:Perches / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D007306:Insecticides; D014874:Water Pollutants, Chemical; D002706:Chlordan