Spatiotemporal Trends Spanning Three Decades Show Toxic Levels of Chemical Contaminants in Marine Mammals

• Published in: Environmental Science & Technology
• Main Authors: Brownlow, A, Baillie, A, Barber, JL, Barnett, J, Davison, NJ, Deaville, R, ten Doeschate, M, Murphy, S, Penrose, R, Perkins, M, Spiro, S, Williams, R, Jepson, PD, Curnick, DJ, Jobling, S
• Format: Article in Journal/Newspaper
• Language: English
• Published: ACS ACS Publications (American Chemical Society) 2023
• Subjects: marine mammals; persistent organic pollutants; temporal trend; ecotoxicology; cetaceans; PCBs; POPs; polychlorinated biphenyls; Lagenorhynchus albirostris; Orca; Orcinus orca
• Online Access: https://bura.brunel.ac.uk/handle/2438/28570; https://doi.org/10.1021/acs.est.3c01881

Data Availability: Aggregated data that support the findings of this study are available to download as part of the Supporting Information. Some of the raw data (e.g., stranding location) cannot be made public due to challenges in ascribing ownership to multiple contributors who were funded through various grants, leading to complexities in the publication of the unprocessed data. However, all of the raw data are available from the authors on request. Supporting Information is available online at https://pubs.acs.org/doi/10.1021/acs.est.3c01881#article_content-right . P.D.J., D.J.C, and S.J. contributed equally to this work. Despite their ban and restriction under the 2001 Stockholm Convention, persistent organic pollutants (POPs) are still widespread and pervasive in the environment. Releases of these toxic and bioaccumulative chemicals are ongoing, and their contribution to population declines of marine mammals is of global concern. To safeguard their survival, it is of paramount importance to understand the effectiveness of mitigation measures. Using one of the world’s largest marine mammals strandings data sets, we combine published and unpublished data to examine pollutant concentrations in 11 species that stranded along the coast of Great Britain to quantify spatiotemporal trends over three decades and identify species and regions where pollutants pose the greatest threat. We find that although levels of pollutants have decreased overall, there is significant spatial and taxonomic heterogeneity such that pollutants remain a threat to biodiversity in several species and regions. Of individuals sampled within the most recent five years (2014–2018), 48% of individuals exhibited a concentration known to exceed toxic thresholds. Notably, pollutant concentrations are highest in long-lived, apex odontocetes (e.g., killer whales (Orcinus orca), bottlenose dolphins (Tursiops truncatus), and white-beaked dolphins (Lagenorhynchus albirostris)) and were significantly higher in animals that stranded on more ...