The intricate network of rivers that winds through Uttarakhand is a lifeline for its rich fauna. The state’s biodiversity is a testament to its natural beauty and ecological significance, thanks to its rivers. These vibrant ecosystems provide a home and water security for over 102 mammal species, 623 bird species, 124 fish species, 69 reptile species, and 19 amphibian species.
Numerous studies have documented the significant diversity of aquatic life. Uttarakhand’s rivers, due to their relatively good water quality and perennial flow, support diverse fish species like Snow Trout and Mahseer, including Golden Mahseer which is a state fish of Uttarakhand. A survey carried out by WWF-India recorded three endemic fish species which are only found in this region.
The Ganga basin and its tributaries, such as Alaknanda, Mandakini and Nandakini, exhibit the highest fish diversity.
Golden Mahseer (Tor putitora) is economically, culturally and ecologically significant. As apex predators, Mahseer fish play a crucial role in maintaining the ecological integrity of river ecosystems. In addition, the presence or absence of Mahseer can be used as a bio-indicator of water quality and overall ecosystem health. Their sensitivity to pollution and habitat degradation makes them valuable indicators of environmental changes.
In addition to fish diversity, a recent survey by the Uttarakhand forest department offers promising news for the state’s other aquatic life. The report estimates 77 gharials (Gavialis gangeticus), 194 otters and 451 muggers (marsh crocodiles) thriving in the state’s rivers.
Previous observations, visual signs and community discussions suggest the presence of three otter species in Uttarakhand—the Eurasian otter (Lutralutra), smooth-coated otter (Lutrogale perspicillata) and Asian small-clawed otter (Aonyx cinerea).
The Eurasian otter is listed as Near Threatened as per IUCN Red List category, while the smooth-coated and Asian small-clawed otters are classified as Vulnerable. A study of four rivers—Kosi, Ramganga, Kho and Song—assessed otter presence outside protected areas. Habitat degradation due to declining flows, increased siltation from land use changes, abstraction of river bed material and other anthropogenic pressures adversely impact fish.
Habitat degradation and unsustainable fishing practices contribute to declining fish catch. Communities report that these factors, along with the low flow due to anthropogenic pressures, consumptive water uses and climate change, have negatively affected fish and their riverine habitats.
Uttarakhand’s rivers are more than just waterways; they are vibrant ecosystems with diverse aquatic floral and faunal biodiversity. Understanding appreciating these aquatic treasures can ensure their continued survival and safeguard the ecological health of these vital freshwater sources. Various studies offer hope for the future of Uttarakhand’s aquatic species. Continued support is crucial to ensure their long-term survival and the health of the state’s vital freshwater ecosystems and their dependent biodiversity. Concerted efforts alone can bring about positive change in the conservation of the state’s aquatic biodiversity.
Dr Vivek Chauhan, Reckitt India Project Lead, with contribution from WWF-India
