Ganga River Cleanup Yields Major Ecological Gains, Study Finds
Sustained efforts by the Central and state governments to clean the Ganga River are now demonstrating clear and measurable ecological improvements, according to a comprehensive study conducted by the Prayagraj-based Central Inland Fisheries Research Institute (CIFRI). The research highlights a marked enhancement in the river's aquatic ecosystem, with significant shifts in fish populations serving as key indicators of improved water quality.
Indian Major Carps Thrive as Water Quality Improves
The study has revealed a substantial increase in the population of Indian Major Carps (IMCs), which are known to thrive exclusively in clean, pristine waters. This positive trend strongly suggests that the Ganga's water quality has improved significantly following years of dedicated cleanup initiatives under the National Mission for Clean Ganga.
Senior scientist and head of CIFRI, Dr. Balasaheb Ramdas Chavan, elaborated on the findings, stating, "Approximately 230 species of fish inhabit the Ganga's aquatic ecosystem. Our research shows a notable rise in the population of IMCs, which comprise four prominent species: Rohu, Catla, Mrigal (Nayan), and Kalbasu. Equally significant is the rapid decline observed in populations of exotic carp species like Common Carp and Tilapia, which typically flourish in polluted waters."
Dramatic Shift in Fish Population Composition
Dr. Chavan provided detailed comparative data illustrating this ecological transformation. Until 2016, IMCs constituted a mere 12% of the total fish catch from the Ganga River. In stark contrast, exotic carp species accounted for 40% during that period, with the remaining 48% consisting of other fish varieties.
The current scenario presents a dramatically different picture. Exotic carps now make up only 20% of the catch, while the population of Indian Major Carps has surged to over 24%. The remaining 56% comprises other indigenous fish species.
"Research and analysis clearly indicate that the population of Indian Major Carps has grown just as rapidly as the population of exotic carps has declined," Dr. Chavan emphasized. "This inverse relationship serves as a crucial biological indicator that the water quality of the Ganga has improved significantly through sustained conservation efforts."
Long-Term Research Under National Clean Ganga Mission
Dr. Dharmanath Jha, another senior scientist at CIFRI, explained that this research has been systematically conducted at various riverbanks in the Sangam region since 2017, operating under the aegis of the National Mission for Clean Ganga.
"Indian Major Carps perform a vital ecological function," Dr. Jha noted. "They feed on decaying vegetation, flowers, leaves, and other organic debris present in the river, effectively acting as natural cleaners for the waterway. Furthermore, a single fish of these species can spawn approximately 250,000 to 300,000 offspring, contributing to rapid population growth."
Broader Ecological and Economic Implications
The increasing population of Indian Major Carps carries important implications beyond water quality indicators. The dolphins found in the Ganga survive primarily by preying on these very fish species. Consequently, researchers anticipate that the rise in fish populations will likely lead to corresponding increases in dolphin numbers, supporting broader biodiversity conservation goals.
This ecological development also holds significant economic promise for local fishing communities. Compared to other fish varieties, there is exceptionally high market demand for Rohu, Catla, Mrigal, and Kalbasu due to their superior nutritional value and better taste. The surge in their population has already led to increased sales for fishermen, with expectations that this trend will substantially improve the economic conditions of communities dependent on the river.
Conservation Efforts Include Strategic Fish Releases
As part of the comprehensive cleanup program, CIFRI has periodically released Indian Carp fingerlings into the Ganga River to bolster native populations. Between 2024 and 2026 alone, approximately nine lakh (900,000) fingerlings have been introduced into the ecosystem. These fish are now successfully multiplying, contributing to the positive population trends documented in the study.
The research from CIFRI provides concrete, scientifically validated evidence that the multi-year, multi-agency efforts to restore the Ganga River are yielding tangible ecological results. The shifting balance from pollution-tolerant exotic species to clean-water-dependent native fish represents a significant milestone in one of India's most ambitious environmental conservation initiatives.
