Scientists have highlighted the potential of freshwater sponges and their associated microbial communities as effective tools for tackling heavy metal pollution in aquatic ecosystems.
According to a recent study, freshwater sponges—among the earliest multicellular organisms—can act both as bioindicators and natural absorbents of toxic metals such as arsenic, lead and cadmium. By filtering large volumes of water, these sponges play a vital role in maintaining ecosystem health and could offer promising solutions for bioremediation.
The findings are based on a study conducted by researchers from the Bose Institute, an autonomous institute under the Department of Science and Technology (DST), who examined freshwater sponges from the Sundarban delta. The research, published in the journal Microbiology Spectrum of the American Society for Microbiology, provides new insights into the ecological role of sponge-associated microbes in polluted environments.
The study revealed that microbial communities living within sponges are distinct from those in the surrounding water and are shaped by both species and habitat. Importantly, the sponges were found to accumulate significantly higher concentrations of toxic metals compared to their environment, highlighting their strong bioaccumulation capacity.
Dr Abhrajyoti Ghosh and his team from the Department of Biological Sciences demonstrated that sponge-associated bacteria are functionally enriched with genes related to metal ion transport, metal resistance and antimicrobial resistance. These traits enable the microbial communities to survive in contaminated habitats while actively contributing to detoxification processes.
The research, supported by the DST-Science and Engineering Research Board National Post-Doctoral Fellowship awarded to Dr Dhruba Bhattacharya, is the first to report on the bacterial diversity of freshwater sponges in the Sundarban region, an area that remains largely underexplored.
Given the widespread heavy metal pollution across the Gangetic plain, scientists say freshwater sponges and their microbial partners could serve as effective bioindicators for monitoring water quality and offer sustainable approaches for managing pollution in estuarine and freshwater ecosystems.
