Cochin backwaters, a micro tidal estuary, undergo a characteristic transformation from a river dominated system during summer monsoon to a tide-dominant system during pre-monsoon season. The present study observes that as the river flow weakens after monsoon, the flushing of the estuary

Heterotrophic bacteria are accounted for the most important proportion of decomposers in the aquatic ecosystems, which are responsible for key process regulating the function and productivity of ecosystem through the microbial loop. Heterotrophic bacteria in the fresh water ecosystem form a major part of the food web and mediate important processes in the carbon budget. As in both fresh water and marine waters, the biomass and size distribution of bacteria are important parameters of ecosystem function.

Physico-chemical analysis of groundwater in Churu block was performed to have a clear picture of water quality so that remedial measures could be worked for. Fluoride higher thatn 2ppm may cause osteoporosis and fluorosis. High nitrate is alarming as it indicates possibility of seepage from sewage.

The surface water quality monitoring in a catchment is one of the most important tools for water management. The western zone of Virudhunagar district in south Tamil Nadu depends upon the surface water from Pillavakkal irrigation system, comprising a number of interconnected surface tanks. The increase in agricultural products and industrial zones in this terrain results in an essential investigation of the surface water quality and soil parameter.

Water quality monitoring of a central Himalayan river, river Kosi was done for a period of one year. The study was done to ascertain the suitability of its water for potable supplies and to generate benchmark data for the management of the river ecosystem, as the river has a great bearing on the socio-agricultural life of the region.

Underground drinking water samples at six different sites of hand pump at J.P. Nagar were collected and analysed for thirteen different water quality parameters following standard methods and procedures. Water quality index (WQI) has been calculated for all the sites using the statistical data of all thirteen parameters and WHO drinking water standards.