Dear Marmamers, My co-authors and I are pleased to share the recent publication of our paper "*Declining concentrations of chlorinated paraffins in endangered St. Lawrence Estuary belugas (Delphinapterus leucas): Response to regulations or a change in diet?*" in *Science of the Total Environment*.
Simond, A.É.; Ross, P.S.; Cabrol, J.; Lesage, V.; Lair, S.; Woudneh, M.B.; Yang, D.; Peng, H.; Colbourne, K.; Brown, T.M. (2023) doi:10.1016/j.scitotenv.2023.161488 <http://10.1016/j.scitotenv.2023.161488> . *ABSTRACT* Very high levels of industrial contaminants in St. Lawrence Estuary (SLE) beluga whales represent one of the major threats to this population classified as endangered under the Species at Risk Act in Canada. Elevated concentrations of short-chained chlorinated paraffins (SCCPs) were recently reported in the blubber of adult male SLE belugas. Recent regulations for SCCPs in North America, combined with their replacement by medium- (MCCPs) and long-chained chlorinated paraffins (LCCPs), highlight the importance of tracking this toxic chemical class. The objectives of this study were to evaluate (1) levels and profiles of chlorinated paraffins (CPs) in samples obtained from carcasses of adult male, adult female, juvenile, newborn, and fetus beluga, and (2) trends in adult male belugas between 1997 and 2018. Factors potentially influencing CP temporal trends such as age, feeding ecology and sampling year were also explored. SCCPs dominated (64 to 100%) total CP concentrations across all age and sex classes, MCCPs accounted for the remaining proportion of total CPs, and LCCPs were not detected in any sample. The chlorinated paraffin homolog that dominated the most in beluga blubber was C12Cl8. Adult male SCCP concentrations from this study were considerably lower (> 2000-fold) than those recently reported in Simond et al. (2020), likely reflecting a previously erroneous overestimate due to the lack of a suitable analytical method for SCCPs at the time. Both SCCPs and total CPs declined over time in adult males in our study (rate of 1.67 and 1.33% per year, respectively), presumably due in part to the implementation of regulations in 2012. However, there is a need to better understand the possible contribution of a changing diet to contaminant exposure, as stable isotopic ratios of carbon also changed over time. The paper can be accessed here: https://doi.org/10.1016/j.scitotenv.2023.161488 All the best, ****************************** *Antoine Simond, Ph.D.* Chercheur postdoctoral | Postdoctoral Research Fellow Simon Fraser University Resource & Environmental Management Pacific Science Enterprise Centre 4160 Marine Drive West Vancouver (BC), Canada V7V 1N6 Courriel | E-mail: [email protected] <[email protected]> ****************************** *I live and work on the unceded territories of the Coast Salish peoples of the šxʷməθkʷəy̓əmaɁɬ təməxʷ (Musqueam), S’ólh Téméxw (Stó:lō), Stz’uminus, Skwxwú7mesh-ulh Temíx̱w (Squamish), and Səl̓ilwətaɁɬ təməxʷ (Tsleil-Waututh) Nations.* *« We feel fundamentally disconnected from nature and therefore not responsible for the ecological consequences of our actions. Once we learn that our very being, essence, health and happiness depend on Mother Earth, we have no choice but to radically shift the way we treat her. » - *David Suzuki.
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