AUTHOR=Richon Camille , Gorgues Thomas , Paul-Pont Ika , Maes Christophe TITLE=Zooplankton exposure to microplastics at global scale: Influence of vertical distribution and seasonality JOURNAL=Frontiers in Marine Science VOLUME=Volume 9 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.947309 DOI=10.3389/fmars.2022.947309 ISSN=2296-7745 ABSTRACT=Microplastics (MP) are ubiquitous contaminants in the ocean. Zooplankton are thus widely exposed to MP ingestion. Here, we use a global coupled physical-biogeochemical model enriched with a 3D representation of MP to assess the global zooplankton exposure to MP. As expected, our results indicate that water MP concentration is highest in the surface layers of subtropical gyres and coastal areas close to major MP sources, which is mostly due to floating MP, while neutral MP contaminate the mesopelagic zone. Additionally, we showed that floating MP may be also transported to the mesopelagic waters during the seasonal deepening of the mixed layer depth. We then estimate zooplankton exposure to MP based on water MP concentrations, plankton biomass and zooplankton grazing rate. Two main drivers lead to high zooplankton exposure to MP: 1) high water MP contamination and 2) intense grazing activity. Seasonally, re-stratification of surface waters may lead to MP vertical concentration coinciding with planktonic blooms, thus increasing contamination risk.