title: Spatial trends of dioxin-like compounds in Atlantic anguillid eels.
abstract: Several temperate freshwater eel stocks have experienced unsustainable declines, yet to be explained. The decline of lake trout (Salvelinus namaycush) in Lake Ontario has been linked to aryl-hydrocarbon receptor agonists such as polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs), and the question remains whether eels are affected similarly by these compounds. Concentrations of PCDD/Fs, dl-PCBs, and PCNs were determined in eels collected at seven locations in eastern Canada including L. Ontario, one location in New York, USA, and one location in Flanders, Belgium. Concentrations varied greatly among origins, indicating dissimilar historic loadings to local areas. The risk to eel reproduction was evaluated with 2,3,7,8-TCDD toxic equivalents, and increased by 10-fold from the least to most contaminated site. The risk to eel recruitment from dioxin-like compounds in American eel using available guidelines is low. The development of a more comprehensive model for eel recruitment risk assessment due to dioxin-like compounds, using eel-specific guidelines, is recommended. Toxic equivalents were 5-fold higher when based on mammalian toxic equivalency factors compared to fish values. About half of the eels captured in L. Ontario exceeded the Canadian guideline for fish consumption (20pg TEQ g(-1) ww), but there were no other exceedances in Canada. The current risk to eel consumers in Canada is low overall, except for highly urbanized and industrialized areas.
authors.affiliation: Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Byer
authors.forename: Mehran
authors.initials: M
authors.lastname: Alaee
authors.forename: R Stephen
authors.initials: RS
authors.lastname: Brown
authors.forename: Michel
authors.initials: M
authors.lastname: Lebeuf
authors.forename: Sean
authors.initials: S
authors.lastname: Backus
authors.forename: Michael
authors.initials: M
authors.lastname: Keir
authors.forename: Grazina
authors.initials: G
authors.lastname: Pacepavicius
authors.forename: John
authors.initials: J
authors.lastname: Casselman
authors.forename: Claude
authors.initials: C
authors.lastname: Belpaire
authors.forename: Kenneth
authors.initials: K
authors.lastname: Oliveira
authors.forename: Guy
authors.initials: G
authors.lastname: Verreault
authors.forename: Peter V
authors.initials: PV
authors.lastname: Hodson
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D001530:Belgium; D002170:Canada; D004147:Dioxins / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity; D004524:Eels / Q000378:metabolism*; D004784:Environmental Monitoring; D008401:Gas Chromatography-Mass Spectrometry; D060106:Lakes; D045483:Rivers; D014481:United States; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000493:pharmacokinetics / Q000633:toxicity
chemical_list: D004147:Dioxins; D014874:Water Pollutants, Chemical