A new actor on the stage of global change: A multi-level perspective on the toxicity of microplastics pollution in amphibians

• Applicant: Dr. Katharina Ruthsatz
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Animal Physiology and Biochemistry
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 533973724

Microplastics (MP) are one of the fastest-growing sources of environmental pollution due to the increase in plastic consumption and a poor plastic waste management. Continuous release, worldwide distribution, and long-term environmental persistence of MP in all ecosystems have recently increased attention on the ecological significance and consequences of plastic pollution. In living systems, MP ingestion can trigger a variety of harmful effects on digestive, endocrine, and nervous systems which might ultimately impair all vital rates. MP can also be accumulated and transferred through the food chain. Considering that amphibian population declines are at the forefront of the biodiversity crisis, understanding the (eco-)toxicological risks posed by MP to amphibians is a highly important research topic for their conservation. However, such risks are still mostly unknown for amphibians. Similarly, research on the effects of the ecologically relevant biofilm colonized MP on animal health is scarce and completely missing for amphibians. The proposed project aims to determine the toxicity of MP pollution in amphibians. In particular, this project will investigate multi-level (i.e., molecular, cellular, organ, and individual) effects of MP ingestion in amphibians at and across different life stages (i.e., larvae, metamorphs, juveniles) on development and growth by analyzing various biomarkers and collect data on size-dependent translocation ability of MP particles and thus, accumulation capacity in order to assess the ecological significance of MP pollution in amphibians across life stages. Also, this study aims to explore the interplay of environmental factors, biofilm formation on MP, and effects of biofilm colonized MP on amphibian health. The project is based on three work packages conducted as laboratory experiments: (WP1), examining the effect of particle size and temperature on biofilm colonization of MP particles, (WP2), investigating the effects of MP ingestion in relation to temperature on the physiology and metabolic health during and after amphibian metamorphosis as well as possible translocation of MP and concomitant long-term accumulation of MP in amphibians across life stages, and (WP3), assessing the MP intake and short-term accumulation at different amphibian life stages. The laboratory study will use the African clawed frog (Xenopus laevis), a well-established model species in (eco-)toxicological studies. The results of this study will enable us to understand the effects of MP on amphibians more holistically and to draw first conclusions on the possible threat of MP on amphibian populations. Further, the results of this study might serve as a basis for appropriate conservation strategies in order to reduce the release of plastic debris into the environment.

• DFG Programme: Research Grants