Prayagraj: Sustained efforts by Centre and state govts to clean the Ganga are showing clear ecological gains, with a marked improvement in the river’s aquatic ecosystem, says a study by the Prayagraj-based Central Inland Fisheries Research Institute (CIFRI).The study has revealed that population of Indian Major Carps (IMCs)– which thrive in clean, pristine waters– has increased in the river indicating that the water quality of the Ganga has improved significantly.Senior scientist and the head of the institute, Dr Balasaheb Ramdas Chavan, said, “Approximately 230 species of fish are found within the Ganga’s aquatic ecosystem. The study shows that there is a rise in the population of IMCs that comprises four prominent species – Rohu, Catla, Mrigal (Nayan) and Kalbasu. Another significant aspect of these findings is the rapid decline in the population of exotic carp species like the Common Carp and Tilapia, which flourish in polluted waters.”He said until 2016, IMCs constituted a mere 12% of the total fish catch from the Ganga. In contrast, exotic carp species accounted for 40%, while the remaining 48% consisted of other varieties. Currently, however, exotic carps make up only 20% of the catch, whereas the population of IMCs has surged to over 24%. The remaining 56% comprises other fish species.“Research and analysis indicate that the population of IMCs has grown just as rapidly as the population of exotic carps has declined. This serves as a key indicator that the water quality of the Ganga has improved significantly,” he said.Dr Dharmanath Jha, a senior scientist at CIFRI, said the research has been underway at various riverbanks of the Sangam region since 2017, under the aegis of the National Mission for Clean Ganga.Jha said, “IMCs feed on decaying vegetation, flowers, leaves and other organic debris present in the river and act as natural cleaners for the waterway. A single fish of these species can spawn approximately 2,50,000 to 300,000 offspring. The dolphins found in the Ganga survive by preying on these very fish. Consequently, it is anticipated that the increase in the fish population will also lead to a rise in the dolphin numbers.”Another significant aspect of this development concerns the local fishermen.Compared to other varieties, there is an exceptionally high market demand for Rohu, Catla, Mrigal and Kalbasu due to their superior nutritional value and better taste. Consequently, the surge in their population has led to increased sales, a trend that is expected to improve the economic condition of the local fishermen.Jha said, under the programme, CIFRI has periodically released Indian Carp fingerlings into the river. Between 2024 and 2026 alone, approximately nine lakh fingerlings have been released. These fish are now multiplying.
