Chronic and Acute Water-Soluble Microplastics Uptake and Effects on Growth and Reproduction of Daphnia magna

This study focuses on the evaluation of chronic and acute effects of the water-soluble microplastics polyvinyl alcohol (PVA) and polymethacrylic acid (PMA) on the growth and reproduction of Daphnia magna. Within the scope of this study, first of all, PVA and PMA microplastics structures were structurally, thermally, and morphologically characterized. The size distributions and dimensional stability of these structures were determined. Then, the microplastics structures, whose structural and dimensional properties were determined, were applied to the growth and reproduction environments of D. magna at different concentrations. The effects of these microplastics on survival parameters, population growth, morphometric data, and lethal concentration were evaluated through short (96-h) and long (21-day) term analyses. In the long-term study, reproductive strategies affecting population density were examined. Acute and chronic experiments were performed in parthenogenetic females. In chronic triplicate experiments evaluating the population structure from which the reproductive data were obtained, the male neonate was recorded only at a concentration of 5 mgL−1 MP-PVA. Decreased lifespan, ephippium production, embryo development, immature eggs, sexual differentiation, and morphologic deformations have been observed in D. magna due to different concentrations of microplastics polymers exposures.