Researchers have detected microplastics in frog tadpoles and their natural pond habitats in the Amazon Rainforest for the first time, highlighting the growing spread of plastic pollution across one of the world’s most biodiverse ecosystems.
The study was conducted by ecologist Fabrielle Barbosa de Araújo and researchers from the Federal University of Pará in Brazil. The team collected water samples and tadpoles from five temporary rainwater ponds located in Gunma Ecological Park in Pará state during April 2025.
The ponds serve as important breeding and larval development sites for amphibians in the Amazon region.
Researchers examined 100 tadpoles from each pond belonging to the Venezuela snouted treefrog, a species commonly found across forests and urban environments in South America. Microplastics were found in every pond sampled and in all tadpoles analysed during the study.
Most of the particles identified were transparent, blue and black plastic fibres made primarily of polyester and similar synthetic materials. According to the researchers, such fibres are commonly linked to untreated sewage, synthetic textiles and fishing-related waste already reported across the Amazon basin.
Araújo said the extent of contamination was particularly concerning because the study area has low human population density and is considered relatively well preserved.
She noted that previous studies had already documented microplastics in Amazon fish, invertebrates, soil and water systems, but this is the first evidence showing contamination in amphibian tadpoles from the region.
The researchers warned that microplastic exposure could pose serious risks to amphibian health. According to the study, the particles may cause genetic and morphological damage, including alterations in blood cells and DNA. Scientists also noted that microplastics can accumulate in tissues and trigger long term physiological changes.
The team believes the tadpoles likely ingested the particles while feeding on algae, fungi and eggs present in pond water.
Freshwater ecologist Jess Hua, who was not involved in the research, described the findings as significant because amphibians are among the world’s most threatened vertebrate groups.
She said freshwater microplastic contamination remains far less studied than marine pollution and stressed that understanding such threats is important for amphibian conservation efforts.
Researchers say the study adds to growing evidence that microplastic pollution has become widespread throughout the Amazon ecosystem reaching even remote freshwater habitats previously considered relatively undisturbed.
The team plans to continue monitoring microplastic contamination in Amazon amphibians to better understand how plastic pollution is affecting biodiversity in the region.