Ecosystem studies on upper region of Ganga River, India

Nutrient and microbial water quality of the upper Ganga River, India: identification of pollution sources

The Ganga River is facing mounting environmental pressures due to rapidly increasing human population, urbanisation, industrialisation and agricultural intensification, resulting in worsening water quality, ecological status and impacts on human health. A combined inorganic chemical, algal and bacterial survey (using flow cytometry and 16S rRNA gene sequencing) along the upper and middle Ganga (from the Himalayan foothills to Kanpur) was conducted under pre-monsoon conditions. The upper Ganga had total phosphorus (TP) and total dissolved nitrogen concentrations of less than 100 μg l^-1 and 1.0 mg l^-1, but water quality declined at Kannauj (TP = 420 μg l^-1) due to major nutrient pollution inputs from human-impacted tributaries (principally the Ramganga and Kali Rivers). The phosphorus and nitrogen loads in these two tributaries and the Yamuna were dominated by soluble reactive phosphorus and ammonium, with high bacterial loads and large numbers of taxa indicative of pathogen and faecal organisms, strongly suggesting sewage pollution sources. The high nutrient concentrations, low flows, warm water and high solar radiation resulted in major algal blooms in the Kali and Ramganga, which greatly impacted the Ganga. Microbial communities were dominated by members of the Phylum Proteobacteria, Bacteriodetes and Cyanobacteria, with communities showing a clear upstream to downstream transition in community composition. To improve the water quality of the middle Ganga, and decrease ecological and human health risks, future mitigation must reduce urban wastewater inputs in the urbanised tributaries of the Ramganga, Kali and Yamuna Rivers.

Bibliography of environmental studies in natural characteristics and anthropogenic influences on the Ganga River

During the second half of the 20th century, the Ganga River ecosystem has been continuously altered by several ongoing anthropogenic processes, accommodating multi-dimensional pressure due to increase of nearly four-fold human population. For solution of any environmental issues of the river, the Earth System Science approach is required to have maximum socio-economic benefits to millions of people living in Indian and Bangladesh. A bibliography containing more than 250 references on environmental studies of the Ganga River was prepared to preserve its ecosystem by providing the baseline support in this regard.