Dear colleagues, I hope this message findsyou well. Iam pleased to share two new contributions on food-web bioaccumulation modelingfor anthropogenic pollutants using marine mammalian food webs. Please, seebelow: Modeling 137Cs bioaccumulation inthe salmon–resident killer whale food web of the Northeastern Pacific followingthe Fukushima Nuclear Accident Science ofThe Total EnvironmentVolume 544, 15 February2016, Pages 56–67doi:10.1016/j.scitotenv.2015.11.097 Juan José Alava& Frank A. P. C. Gobas Abstract To track the longterm bioaccumulation of 137Cs in marine organisms off the PacificNorthwest coast of Canada, we developed a time dependent bioaccumulation modelfor 137Cs in a marine mammalian food web that included fish-eatingresident killer whales. The model outcomes show that 137Cs can beexpected to gradually bioaccumulate in the food web over time as demonstratedby the increase of the apparent trophic magnification factor of 137Cs,ranging from 0.76 after 1 month of exposure to 2.0 following 30 yearsof exposure. 137Cs bioaccumulation is driven by relatively rapiddietary uptake rates, moderate depuration rates in lower trophic levelorganisms and slow elimination rates in high trophic level organisms. Modelestimates of the 137Cs activity in species of the food web, based oncurrent measurements and forecasts of 137Cs activities in oceanicwaters and sediments off the Canadian Pacific Northwest, indicate that the longterm 137Cs activities in fish species including Pacific herring,wild Pacific salmon, sablefish and halibut will remain well below the current 137Cs-CanadaAction Level for consumption (1000 Bq/kg) following a nuclear emergency.Killer whales and Pacific salmon are expected to exhibit the largest long term 137Csactivities and may be good sentinels for monitoring 137Cs in theregion. Assessment of the long term consequences of 137Cs releasesfrom the Fukushima aftermath should consider the extent of ecologicalmagnification in addition to ocean dilution. Alava, J. J., Gobas, F. A. 2016. Modeling 137Cs bioaccumulation in the salmon-resident killerwhale food web of the Northeastern Pacific following the Fukushima NuclearAccident. Science of the Total Environment 544: 56-67doi:10.1016/j.scitotenv.2015.11.097 Free access to this articleis available from the following link and valid for 50 days, until January 22,2016: http://authors.elsevier.com/a/1S8a5B8ccV62y Alternatively,it can be found at:https://www.researchgate.net/profile/Juan_Jose_Alava/contributions Food Web BioaccumulationModel for Resident Killer Whales from the Northeastern Pacific Ocean as a Toolfor the Derivation of PBDE-SedimentQuality Guidelines. Archives of EnvironmentalContamination and ToxicologyFirstonline: 20 August 2015 pp 1-14 doi:10.1007/s00244-015-0215-y Juan José Alava, Peter S. Ross & Frank A. P. C. Gobas Abstract Residentkiller whale populations in the NE Pacific Ocean are at risk due to theaccumulation of pollutants, including polybrominated diphenyl ethers (PBDEs).To assess the impact of PBDEs in water and sediments in killer whale criticalhabitat, we developed a food web bioaccumulation model. The model was designedto estimate PBDE concentrations in killer whales based on PBDE concentrationsin sediments and the water column throughout a lifetime of exposure. Calculatedand observed PBDE concentrations exceeded the only toxicity reference valueavailable for PBDEs in marine mammals (1500 μg/kg lipid) in southernresident killer whales but not in northern resident killer whales. Temporaltrends (1993–2006) for PBDEs observed in southern resident killer whales showeda doubling time of ≈5 years. If current sediment quality guidelinesavailable in Canada for polychlorinated biphenyls are applied to PBDEs, it canbe expected that PBDE concentrations in killer whales will exceed availabletoxicity reference values by a large margin. Model calculations suggest that aPBDE concentration in sediments of approximately 1.0 μg/kg dw producesPBDE concentrations in resident killer whales that are below the currenttoxicity reference value for 95 % of the population, with this valueserving as a precautionary benchmark for a management-based approach toreducing PBDE health risks to killer whales. The food web bioaccumulation modelmay be a useful risk management tool in support of regulatory protection forkiller whales. Alava, J.J., Ross, P.S., Gobas, A.P.C. 2015. Food web bioaccumulationmodel for resident killer whales from the Northeastern Pacific Ocean as a toolfor the derivation of PBDE-Sediment Quality Guidelines. Archives of EnvironmentalContamination and Toxicology. doi: 10.1007/s00244-015-0215-y The article can be found at https://www.researchgate.net/publication/280740512_Food_Web_Bioaccumulation_... Or obtained from the publisher: http://link.springer.com/article/10.1007/s00244-015-0215-y?wt_mc=internal.ev... Best Wishes!!! Juan José Alava -----------------------------------------------------------------------Juan Jose Alava, PhD Adjunct Professor Resource and Environmental Management, Faculty of Environment, Simon Fraser University 8888 University Drive, Burnaby, British Columbia V5A 1S6,Canada E-mail: jalavasa@sfu.ca https://www.researchgate.net/profile/Juan_Jose_Alava/contributions?ev=prf_ac...