Developmental Polyethylene Microplastic Fiber Exposure Entails Subtle Reproductive Impacts in Juvenile Japanese Medaka (Oryzias latipes)

Abstract

Microplastic pollution has been recognized as a potential threat to environmental and human health. Recent studies have shown that microplastics reside in all ecosystems and contaminate human food/water sources. Microplastic exposure has been shown to result in adverse effects related to endocrine disruption; however, data are limited regarding how exposure to current environmental levels of microplastics during development may impact reproductive health. To determine the impact of environmentally relevant, chronic, low‐dose microplastic fibers on fish reproductive health, juvenile Japanese medaka were exposed to five concentrations of polyethylene fibers for 21 days, and reproductive maturity was examined to assess the later life consequences. Fecundity, fertility, and hatching rate were evaluated to determine the organismal level impacts. Gonadal tissue integrity and stage were assessed to provide insights into potential tissue level changes. Expression of key reproductive genes in male and female gonads provided a molecular level assessment. A significant delay in hatching was observed, indicating cross‐generational and organismal level impacts. A significant decrease in 11‐beta‐dehydrogenase isozyme 2 (HSD11 β2) gene expression in male medaka indicated adverse effects at the molecular level. A decrease in male expression of HSD11 β2 could have an impact on sperm quality because this enzyme is crucial for conversion of testosterone into the androgen 11‐ketotestosterone. Our study is one of the first to demonstrate subtle impacts of virgin microplastic exposure during development on later life reproductive health. The results suggest a possible risk of polyethylene fiber exposure for wild fish during reproductive development, and populations should be monitored closely, specifically in spawning and nursery regions. Environ Toxicol Chem 2022;41:2848–2858. © 2022 SETAC

Microplastic Pollution: Threats and Impacts on Global Marine Ecosystems

“…Furthermore, the potential effects of microplastics on the genetic and physiological levels of marine organisms are a significant concern. Recent studies suggest that microplastic exposure may cause genetic alterations and affect the reproductive success of marine species [138][139][140].…”

The Positive Effects of In Vivo/In Vitro Suplementation of Nanoparticles on Semen

“…The exposure of larvae to polyethylene microplastics resulted in a noteworthy decrease in the gene expression of 11-beta-dehydrogenase isozyme 2 (HSO11β2), which is directly linked to sperm quality during the developmental stage. This decrease led to poor sperm quality in the affected individuals (DiBona, Haley et al 2022). Although it is encouraging that microplastics are not transmitted to the next generation, the increasing concentration of microplastics in freshwater and oceans is posing limitations on fish reproduction.…”

Low-Density Microplastics in Recreational Parks of Al Ain, United Arab Emirates: Abundance, Composition, and Potential Effects on Soil Health

“…Airborne plastic particles can be inhaled and may lead to disturbances in the respiratory system [11]. In various aquatic animals, such as brine shrimps [12], water fleas [13], pacific oysters [14], marine medaka [15], sea urchins [16], marine copepods [17], and zebrafish [18], exposure to MPs has been linked to reproductive toxicity. Recreational parks, characterized by the harmonious coexistence of human activity and biodiversity, serve as an ideal setting to investigate the extent and nature of microplastic contamination in such environments.…”