Effect of Climatic Changes on Aquatic Fauna of District Shahjahanpur, Uttar Pradesh, India

Abstract

District Shahjahanpur, situated in the Rohilkhand region of Uttar Pradesh, is drained by the Garha, Khannaut, Deoha, Kali Nadi, and Kathna rivers, along with numerous seasonal streams, oxbow lakes, and ponds. These aquatic ecosystems harbour rich freshwater biodiversity including ichthyofauna, amphibians, molluscs, and crustaceans. The present study (2020–2024) investigates the multifaceted impacts of climate change on the aquatic fauna of the district through field surveys, water quality monitoring, hydrological records, and socio-ecological interviews. Results indicate a mean annual temperature rise of 1.4°C over two decades, a 27% reduction in mean annual river discharge of the Garha River, a threefold increase in dry-bed days per year, and dissolved oxygen decline of 25% during the pre-monsoon period. These changes correlate with significant population declines (38–62%) in ecologically sensitive species including Tor tor (mahseer), Mystus seenghala, and Bagarius bagarius. Breeding phenology shifts, thermal kill events, and habitat fragmentation are documented as key mechanisms of impact. Conservation recommendations are provided including minimum environmental flow mandates, riparian buffer restoration, seasonal fishing bans, and wetland protection under the Wetlands Rules, 2017.