My research explores how zooplankton interact with small microplastics (SMPs; < 300 um) in marine ecosystems, focusing on ingestion, selectivity, and the environmental drivers of exposure. Zooplankton occupy a key position at the base of aquatic food webs, and understanding how they encounter and ingest MPs provides critical insight into the biological pathways through which plastics enter trophic systems.
Through extensive field-based surveys and laboratory analyses, I investigate how environmental conditions—such as stratification, salinity gradients, and particle availability—shape the composition and size of MPs ingested by dominant copepod species. These studies integrate ecological observations with advanced spectroscopic analyses (µFTIR) for accurate polymer identification and quantification.
A central component of my work involves method development for the detection and characterization of MPs in zooplankton. This includes the refinement of sample preparation protocols, contamination control, and particle isolation techniques to improve detection limits and ensure comparability across studies. I also work toward the standardization and harmonization of ingestion analyses, contributing to global initiatives that aim to align laboratory workflows, data reporting formats, and QA/QC procedures.
Key Publications
Alfonso M.B., Nakano, H., Jandang, S., Chavanich, S., Viyakarn, V., & Isobe, A. (2024). Small microplastic ingestion by the calanoid Centropages furcatus in the Gulf of Thailand. Science of the Total Environment, 930, 172837.
Alfonso, M. B., Lindsay, D. J., Arias, A. H., Nakano, H., Jandang, S., & Isobe, A. (2023). Zooplankton as a suitable tool for microplastic research. Science of the Total Environment, 167329.
Related Projects and Grants
- KAKENHI (JP22K21328): “Microplastic pollution impact on the Gulf of Thailand: insights from water samples assessment and ingestion by zooplankton as complementary tools” (2022–2023)
- KAKENHI (JP23K17048): “Assessing the rainfall and tide effect on the presence and exposure of microplastics to zooplankton in subtropical estuaries intensely polluted by plastics” (2023–2024)
- KAKENHI (JP25K21393): “The effect of plankton dynamics on characteristics and vertical distribution of ocean small microplastics” (2025–2026)
- SATREPS Japan–Thailand Project (2022-2026)
