Pune, India has experienced a significant 27% decline in snail biodiversity over the past six decades, primarily attributed to rapid urbanization, according to a recent study.
Conducted by researchers from Pune, Karnataka, and a Canadian university, the study highlights the serious threat this decline poses to the aquatic ecosystem in the Pune metropolitan area. The loss of snail diversity is expected to have a cascading effect on freshwater fish populations.
Published in the journal Biodiversity, the study identifies increasing water pollution levels as a major cause of the extinction of local gastropods, which are typically found in streams and rivers. Urban runoff, sewage influx, and garbage dumping are significant contributors to this alarming trend.
Researchers sampled snails from 24 urban locations in Pune and Pimpri-Chinchwad between 2021 and 2023, recording only 16 species from eight families, a decline from 22 species observed in earlier surveys in 1963 and 1979. Notably, 41% of the observed species were classified as rare, with Racesina luteola being the most abundant.
The study also found three invasive snail species, including Physella acuta, which were primarily located in the Mutha River. The highest species richness was observed at the Pavana River.
Increased human activity has led to habitat destruction and pollution, causing a decline in habitat specialist snails like Paludomus sp. and Paracrostoma sp., while generalist species like Racesina luteola thrive in polluted waters.
Researchers emphasize that gastropods serve as indicators of habitat health, making their preservation crucial for maintaining ecosystem balance. Effective pollution management is essential to mitigate the impacts of urbanization on freshwater biodiversity.
Moreover, the study warns that urbanization has introduced non-native species, which pose a serious threat to local flora and fauna. Awareness campaigns are necessary to prevent the release of invasive species, such as the golden apple snail, into natural water bodies.