Acute and multigenerational toxicity of polylactic acid microplastics on a copepod bioindicator

Bioplastics such as polylactic acid are actually promoted as eco-friendly alternatives to fossil fuel-derived plastics, yet bioplastic toxicity remains poorly known. Here we studied the acute and multigenerational effects of polylactic acid microplastics on the copepod Eurytemora affinis, a bioindicator species of zooplankton. Results on acute toxicity revealed that lethal concentration values are higher for adult males, of 134.6 mg microplastic/L, than for adult females, of 106.9 mg/L. In multigeneration exposure, 400 µg/L polylactic acid microplastics induced higher mortality, production of smaller-sized eggs, elongation of the naupliar phase, and offspring with lower fitness. This led to reduction in female body size, including prosome length, width, and volume. Noteworthy, we also observed a recovery in copepod survival and reproductive parameters in the fifth filial generation.