Predicting global killer whale population collapse from PCB pollution

New publication by Jean-Pierre Desforges, Ailsa Hall, Bernie McConnell, Aqqalu Rosing-Asvid, Jonathan L. Barber, Andrew Brownlow, Sylvain De Guise, Igor Eulaers, Paul D. Jepson, Robert J. Letcher, Milton Levin, Peter S. Ross, Filipa Samarra, Gísli Víkingsson, Christian Sonne-Hansen and Rune Dietz.

2018.10.09 | Peter Schmidt Mikkelsen

Abstract:

Killer whales (Orcinus orca) are among the most highly polychlorinated biphenyl (PCB)–contaminated mammals in the world, raising concern about the health consequences of current PCB exposures. Using an individual-based model framework and globally available data on PCB concentrations in killer whale tissues, we show that PCB-mediated effects on reproduction and immune function threaten the long-term viability of >50% of the world’s killer whale populations. PCB-mediated effects over the coming 100 years predicted that killer whale populations near industrialized regions, and those feeding at high trophic levels regardless of location, are at high risk of population collapse. Despite a near-global ban of PCBs more than 30 years ago, the world’s killer whales illustrate the troubling persistence of this chemical class.  

Science  28 Sep 2018: Vol. 361, Issue 6409, pp. 1373-1376. DOI: 10.1126/science.aat1953        

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