Spatial and seasonal variations in nutrient load and trophic status of Ganga and Yamuna rivers in Uttar Pradesh, India

Abstract Nutrient loading in aquatic systems from anthropogenic sources is a worldwide concern. The Ganga the most important river India, but pollution currently severely threatening its biodiversity and long-term environmental viability. Water samples were taken 36 locations along length of Yamuna rivers Uttar Pradesh analysed for nutrient concentration to evaluate load, eutrophication danger, trophic status. average NO3-N, PO4-P, NH4-N, SiO2-Si exceeded values unpolluted rivers, indicating contribution sources. NO3-N NH4-N showed significant spatial variation, PO4-P seasonal variation study area. DIN/DIP ratio area 16:1, phosphate-limiting condition phytoplankton development. DSi/DIN value declining trend downstream region both with <1, nitrate leading eutrophic conditions. Indicator Coastal Eutrophication Potential (ICEP) positive value, that due nitrogen pollution. Trophic State Index (TSI) indicated super-eutrophic conditions existed River (65.62) hypereutrophic (75.55) Pradesh.