Impacts and transport of microplastics: Population dynamics in frogs and the transfer between aquatic and terrestrial...

Increased plastic production has led to severe environmental issues, with microplastics (MPs) becoming widespread contaminants. Amphibians, particularly frogs, are crucial bioindicators because of their permeable skin and biphasic life cycles, making them highly vulnerable to pollutants. This study examined the effects of MPs on Dryophytes japonicus, focusing on hatching, survival, growth, and metamorphosis. We also explored how frogs facilitate the transfer of MPs from aquatic to terrestrial environments. Using an individual-based modeling (IBM) approach, nine male-female pairs were observed in controlled breeding environments. Survival probabilities were analyzed using Kaplan-Meier estimates, and population dynamics were simulated for over 20 years under varying resource conditions. The results demonstrated significantly lower survival rates in the MP-exposed groups. Simulations indicated that exposed populations declined continuously under resource limitation, whereas MP transfer was the highest under high-density, resource-rich conditions. The control groups had larger populations, but were more vulnerable to extinction, whereas the treatment groups showed resilience to resource stress. Frogs may act as vectors, spreading MPs into terrestrial ecosystems, and contributing to soil contamination and trophic disruption. To mitigate these effects, conservation strategies such as habitat restoration, pollution control, and disease management are essential for preserving amphibian populations and ecosystem balance.