Dear MARMAM colleagues, On behalf of my co-authors, I am excited to share our new publication. We measured the microplastic exposure of Bryde’s and Sei whales in the Hauraki Gulf of New Zealand and inferred whether this exposure comes from the environment or the food. Zantis L.J., Bosker T., Lawler F., Nelms S.E., O’Rorke R., Constantine R., Sewell M. and E.L. Carroll, 2021. Assessing microplastic exposure of large marine filter-feeders. Science of the Total Environment, 151815, http://dx.doi.org/10.1016/j.scitotenv.2021.151815 Abstract: Large filter-feeding animals are potential sentinels for understanding the extent of microplastic pollution, as their mode of foraging and prey mean they are continuously sampling the environment. However, there is considerable uncertainty about the total and mode of exposure (environmental vs trophic). Here, we explore microplastic exposure and ingestion by baleen whales feeding year-round in coastal Auckland waters, New Zealand. Plastic and DNA were extracted concurrently from whale scat, with 32 ± 24 (mean ± SD, n = 21) microplastics per 6 g scat sample detected. Using a novel stochastic simulation modeling incorporating new and previously published DNA diet information, we extrapolate this to total microplastic exposure levels of 24,028 (95% CI: 2119, 69,270) microplastics per mouthful of prey, or 3,408,002 microplastics (95% CI: 295,810, 10,031,370) per day, substantially higher than previous estimates for large filter-feeding animals. Critically, we find that the total exposure is four orders of magnitude more than expected from microplastic measurements of local coastal surface waters. This suggests that trophic transfer, rather than environmental exposure, is the predominant mode of exposure of large filter feeders for microplastic pollution. Measuring plastic concentration from the environment alone significantly underestimates exposure levels, an important consideration for future risk assessment studies. Full text and PDF are available at: https://www.sciencedirect.com/science/article/pii/S0048969721068911?via%3Dih... Please feel free to contact me at zantislaurajulia@gmail.com<mailto:zantislaurajulia@gmail.com> if you have any questions or comments, or would like a copy of the PDF. Best wishes, Laura Zantis PhD Candidate, Department of Environmental Biology Institute of Environmental Sciences (CML) | Leiden University e: l.j.zantis@cml.leidenuniv.nl<mailto:l.j.zantis@cml.leidenuniv.nl> | t: @ZantisLaura w: https://www.universiteitleiden.nl/en/staffmembers/laura-julia-zantis