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Updated: Mar 8, 2026
Accumulation and Distribution of Fluorescent Microplastics in the Early Life Stages of Zebrafish
Published on: July 4, 2021
Assessment of microplastic-sorbed contaminant bioavailability through analysis of biomarker gene expression in larval
Victoria A Sleight1, Adil Bakir2, Richard C Thompson3
1School of Marine Science and Engineering, Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth PL4 8AA, UK; British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK; Institute of Life and Earth Sciences, School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh EH14 4AS, UK.
Abstract:
Microplastics (MPs) are prevalent in marine ecosystems. Because toxicants (termed here "co-contaminants") can sorb to MPs, there is potential for MPs to alter co-contaminant bioavailability. Our objective was to demonstrate sorption of two co-contaminants with different physicochemistries [phenanthrene (Phe), log10Kow=4.57; and 17α-ethinylestradiol (EE2), log10Kow=3.67] to MPs; and assess whether co-contaminant bioavailability was increased after MP settlement. Bioavailability was indicated by gene expression in larval zebrafish. Both Phe and EE2 sorbed to MPs, which reduced bioavailability by a maximum of 33% and 48% respectively. Sorption occurred, but was not consistent with predictions based on co-contaminant physicochemistry (Phe having higher log10Kow was expected to have higher sorption). Contaminated MPs settled to the bottom of the exposures did not lead to increased bioavailability of Phe or EE2. Phe was 48% more bioavailable than predicted by a linear sorption model, organism-based measurements therefore contribute unique insight into MP co-contaminant bioavailability.
