Review on the ecotoxicological impacts of plastic pollution on the freshwater invertebrate Daphnia

Abstract

The environmental impacts of plastic pollution have recently attracted universal attention, especially in the aquatic environment. However, research has mostly been focused on marine ecosystems, even though freshwater ecosystems are equally if not more polluted by plastics. In addition, the mechanism and extent to which plastic pollution affects aquatic biota and the rates of transfer to organisms through food webs eventually reaching humans are poorly understood, especially considering leaching hazardous chemicals. Several studies have demonstrated extreme toxicity in freshwater organisms such Daphnia. When such keystone species are affected by ambient pollution, entire food webs are destabilized and biodiversity is threatened. The unremitting increase in plastic contaminants in freshwater environments would cause impairments in ecosystem functions and structure, leading to various kinds of negative ecological consequences. As various studies have reported the effects on daphnids, a consolidation of this literature is critical to discuss the limitations and knowledge gaps and to evaluate the risk posed to the aquatic environment. This review was undertaken due to the evident need to evaluate this threat. The aims were to provide a meaningful overview of the literature relevant to the potential impact of plastic pollution and associated contaminants on freshwater daphnids as primary consumers. A critical evaluation of research gaps and perspectives is conducted to provide a comprehensive risk assessment of microplastic as a hazard to aquatic environments. We outlined the challenges and limitations to microplastic research in hampering better‐focused investigations that could support the development of new plastic materials and/or establishment of new regulations.

Polystyrene microplastics induce autophagy and apoptosis in birds lungs via PTEN/PI3K/AKT/mTOR

“…Plastic is everywhere: the sea, wastewater treatment plants in oceans, lakes, rivers, estuaries, air, sediment, landfills, and water 6,7 . The existence of polystyrene microplastics (PS‐MPs), which is as a new environmental pollutant because of their potential toxic effects on humans and ecosystems, is causing concern 8 . The invertebrates of aquatic organisms, poultry, birds, vertebrates, and other invertebrates often mistake PS‐MPs for food, thus, causing them to accumulate along the food chain to threaten human health 9,10 …”

“…6,7 The existence of polystyrene microplastics (PS-MPs), which is as a new environmental pollutant because of their potential toxic effects on humans and ecosystems, is causing concern. 8 The invertebrates of aquatic organisms, poultry, birds, vertebrates, and other invertebrates often mistake PS-MPs for food, thus, causing them to accumulate along the food chain to threaten human health. 9,10 Compelling evidence shows that ingested PS-MPs lead to various aspects of tissue or organ dysfunction in vitro and vivo.…”

Potential for high toxicity of polystyrene nanoplastics to the European Daphnia longispina

“…Amme 12, Amme 3, Amme 51. galeata × longispina) (Griebel et al, 2015). Thus, genetic variation in responses to plastic particle exposure helps to explain some of the contradictory results among Daphnia studies based on single genotypes (reviewed in (Samadi et al, 2022)). This clone-speci c nature of Daphnia responses to nanoplastics demonstrates that there might be potential for evolutionary selection and adaptations of populations in contaminated sites.…”

Polystyrene nanoplastics differentially influence the outcome of infection by two microparasites of the host Daphnia magna

“…Owing to their status as a widely used model for ecotoxicological studies and their excellent suitability for advanced ecotoxicogenomics [17,18], zooplankters of the genus Daphnia have contributed to an impressive body of work on this matter. Over the course of the past decade, numerous publications have addressed the implications of microplastic particles [19,20] and, more recently, NPs [21][22][23] on the lifehistory and physiological responses of this freshwater model (reviewed in [24]). Besides frequent adverse effects on parameters of individual performance, such as longevity, body size and lifetime offspring production [14,25], typical responses of Daphnia to polystyrene NPs include enhanced production of reactive oxygen species, increased AMP kinase activity and direct changes in the levels of gene transcription, including stress defence-related loci [26][27][28].…”