Dear Marman colleagues, I hope everyone is doing well. I am pleased to share on behalf of my co-authors, our new paper on "Polycyclic aromatic hydrocarbon (PAH) source identification and a maternal transfer case study in threatened killer whales (Orcinus orca) of British Columbia, Canada". This full text of the article is available as an open-access publication at the following links: https://www.nature.com/articles/s41598-023-45306-whttps://rdcu.be/dtYrx Abstract The northeastern Pacific (NEP) Ocean spans the coast of British Columbia (Canada) and is impacted by anthropogenic activities including oil pipeline developments, maritime fossil fuel tanker traffic, industrial chemical effluents, agricultural and urban emissions in tandem with stormwater and wastewater discharges, and forest wildfires. Such events may expose surrounding marine environments to toxic polycyclic aromatic hydrocarbons (PAHs) and impact critical habitats of threatened killer whales (Orcinus orca). We analyzed skeletal muscle and liver samples from stranded Bigg’s killer whales and endangered Southern Resident killer whales (SRKWs) for PAH contamination using LRMS. C3-phenanthrenes/anthracenes (mean: 632 ng/g lw), C4-dibenzothiophenes (mean: 334 ng/g lw), and C4-phenanthrenes/anthracenes (mean: 248 ng/g lw) presented the highest concentrations across all tissue samples. Diagnostic ratios indicated petrogenic-sourced contamination for SRKWs and pyrogenic-sourced burdens for Bigg’s killer whales; differences between ecotypes may be attributed to habitat range, prey selection, and metabolism. A mother-fetus skeletal muscle pair provided evidence of PAH maternal transfer; low molecular weight compounds C3-fluorenes, dibenzothiophene, and naphthalene showed efficient and preferential exposure to the fetus. This indicates in-utero exposure of PAH-contamination to the fetus. Our results show that hydrocarbon-related anthropogenic activities are negatively impacting these top predators; preliminary data found here can be used to improve oil spill and other PAH pollution management and regulation efforts, and inform policy to conserve killer whale habitats in the NEP. Citation: Lee, K., Raverty, S., Cottrell, P., Zoveidadianpour, Z., Cottrell, B., Price D., Alava, J.J. 2023. Polycyclic aromatic hydrocarbons (PAHs) in threatened killer whales (Orcinus orca) of British Columbia, Canada: Contaminant source identification and a maternal transfer case study. Scientific Reports 13 (2258): 1-14 https://doi.org/10.1038/s41598-023-45306-w A media release news via the University of British Columbia (UBC) is also available at the following link: Toxic chemicals found in oil spills and wildfire smoke detected in killer whaleshttps://urldefense.com/v3/__https://news.ubc.ca/2023/12/19/toxic-chemicals-f... A previous paper on a similar topic regarding contaminants of emerging concern in killer whales from the Northeastern Pacific was also published early this year: Lee, K., Alava, J. J., Cottrell, P., Cottrell, L., Grace, R., Zysk, I., Raverty, S. 2023.Emerging Contaminants and New POPs (PFAS and HBCDD) in Endangered Southern Resident and Bigg’s (Transient) Killer Whales (Orcinus orca): In Utero Maternal Transfer and Pollution Management Implications Environmental Science & Technology 57 (1): 360-374. https://doi.org/10.1021/acs.est.2c04126 Wishing you all Hally Holidays and a Happy New Year 2021! Juan José ------------------------------------------------------ Juan Jose Alava, Ph.D. (he/el/him/his) Honorary Research Associate Principal Investigator, Ocean Pollution Research Unit (OPRU) Institute for the Oceans and Fisheries, The University of British Columbia AERL 2202 Main Mall | Vancouver, BC V6T 1Z4 Canada OPRU: https://oceanpollution.oceans.ubc.ca http://oceans.ubc.ca/juan-jose-alava/ https://twitter.com/UBC_OPRU https://www.facebook.com/ubcoceanpollution I acknowledge being grateful and humble located on the traditional, ancestral, and unceded territory of the xwməθkwəy̓əm (Musqueam), Skwxwú7mesh (Squamish) and Səl̓ílwətaɬ (Tsleil-Waututh) Nations.