Habitat suitability modeling of a conservation-significant fish species of the Kosi River,Uttarakhand, India

Water quality plays a vital role in the sustenance of aquatic life, including fish. Therefore, an inclusive understanding of water quality parameters can be considered an essential step in framing the conservation and management strategy of an aquatic ecosystem. This study examines the habitat suitability of a conservation-significant fish, the Tor putitora, and two associated fishes, the Labeo dyocheilus and the Garra gotyla, in relation to the water quality parameters of the Kosi River. Four crucial water quality parameters, water temperature, dissolved oxygen, electrical conductivity, and pH, were included in the QUAL2K modeling. Furthermore, hydrological processes were modeled using the soil and water assessment tool, and flow was used as an input in the QUAL2K model. The simulated water quality was correlated with fish habitat and analyzed through the analytical hierarchical process (AHP). Results suggested that the habitats of the Kosi were more suitable in the post-monsoon rather than pre-monsoon. Tor putitora, the flagship species of the Kosi, preferred the river habitats with a lower water temperature and higher dissolved oxygen for spawning. Thus, we recommend securing such habitats and managing them in collaboration with local communities for the long-term conservation of this endangered Himalayan species.