title: A twenty-one year temporal trend of persistent organic pollutants in St. Lawrence Estuary beluga, Canada.
abstract: Persistent organic pollutants (POPs) were measured in blubber from 144 stranded adult belugas (Delphinapterus leucas) found on the shores of the St. Lawrence Estuary (SLE) between 1987 and 2007. Temporal trends of POP concentrations (ln transformed) in beluga were described by three models, zero slope (ZS), linear (L) and two-segment piecewise (PW). Often two but sometimes all three models were equivalent in describing temporal trends based on Akaike's Information Criterion for small sample sizes. Over this 21-year time period, concentrations of most legacy POPs, including PCBs, DDTs and HCHs, exhibited relatively weak (≤11% per year) but significant decreasing trends in beluga. For PBDEs, temporal trends were best described by a PW model, characterizing a rapid increase until 1997-1998 followed by a slower increase for males and a steady-state for females. Potential cofactors such as blubber lipid content and carcass state of preservation did not show any significant temporal trends over the time period considered. Nitrogen stable isotope ratios (δ(15)N) in beluga liver, a proxy of trophic level, could not be associated to any effect on temporal trends of POP concentrations in beluga. Several POPs exhibited significant relationships with age of beluga and data were age-adjusted. Temporal trends of POP concentrations adjusted for age of beluga were reassessed but results were essentially identical as those obtained with the original POP data. Overall, POP temporal trends observed in SLE beluga are consistent with changes expected from regulations and restrictions in the use of these compounds in developed countries.
authors.affiliation: Department of Fisheries and Oceans, Maurice Lamontagne Institute, 850 Route de la Mer, Mont-Joli, Québec, Canada. Electronic address: michel.lebeuf@dfo-mpo.gc.ca.
authors.forename: Michel
authors.initials: M
authors.lastname: Lebeuf
authors.affiliation: Department of Fisheries and Oceans, Maurice Lamontagne Institute, 850 Route de la Mer, Mont-Joli, Québec, Canada.
authors.forename: Lena
authors.initials: L
authors.lastname: Measures
authors.affiliation: Department of Fisheries and Oceans, Maurice Lamontagne Institute, 850 Route de la Mer, Mont-Joli, Québec, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Noël
authors.affiliation: Department of Fisheries and Oceans, Maurice Lamontagne Institute, 850 Route de la Mer, Mont-Joli, Québec, Canada.
authors.forename: Meriem
authors.initials: M
authors.lastname: Raach
authors.affiliation: Department of Fisheries and Oceans, Maurice Lamontagne Institute, 850 Route de la Mer, Mont-Joli, Québec, Canada.
authors.forename: Steve
authors.initials: S
authors.lastname: Trottier
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D050643:Beluga Whale / Q000378:metabolism*; D002170:Canada; D004784:Environmental Monitoring; D063366:Estuaries; D005260:Female; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism; D008297:Male; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D055768:Halogenated Diphenyl Ethers; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls
keywords: Beluga whale; Models; Persistent organic pollutants; St. Lawrence Estuary; Stable isotope; Temporal trends