Distribution and enrichment of six elements (iron, zinc, copper, lead, cadmium and manganese) in surface bed sediments, collected from seventeen selected locations during pre-monsoon and postmonsoon periods, of the tropical Chottanagpur plateau river Subarnarekha along with the ecological risks involved were investigated. Owing to the rich occurrence of mineral resources, the Subarnarekha river basin has a large scale presence of industrial and mining units especially in the Indian State of Jharkhand. An assessment, which involved examining distribution pattern of elements, comparative studies with sediment quality guidelines (SQGs) and geochemical background values and a sequential and integrated index analyses approach (containing contamination factor (CF), pollution load index (PLI), contamination degree (CD), enrichment factor (EF), geo-accumulation index (Igeo) and potential ecological risk index (PERI)), was followed to estimate enrichment and risks of elements in the bed sediments. Sediments collected from areas having abundance of population, industrial conglomerates and mining units recorded elevated element concentrations, which exceeded SQGs, and significantly higher values of CF, CD, PLI, EF, Igeo and PERI. Cadmium demonstrated surprising regularity in its enrichment; contributed most to the ecological risks; and high toxicity risks due to cadmium exceeded 64% of the sites. Moreover, chronic exposures of other elements would also lead to similar ecological risks. In addition to revealing potential ecological risks due to cadmium and other elements our investigation markedly highlighted anthropogenic control over sediment quality deterioration and some immediate sediment quality management strategies are needed to remediate and control river bed contamination.

The present manuscript is an account of the studies conducted on some well known surface water bodies in India, with special emphasis on the river systems, to evaluate their quality status. The review covers the water quality estimation and identification of sources contributing to water quality deterioration. Commonly employed physicochemical and biological parameters as indicators of water quality have been thoroughly discussed. Some possible measures to prevent and control pollution of water bodies have also been provided. The review also covers assessment of bed sediment environment of the surface water bodies. Many studies are available on quality assessment of surface waters and their bed sediments. However, currently, there is no literature available which compiles the works on some recent assessment of water bodies, commonly applied water quality indicators in research programmes, sources of pollution and possible pollution mitigation measures. This review is the first such attempt in this direction.

Ponds are an integral component of the hydrological system; and perform diverse roles in the biosphere. Studies on pond ecosystems are, however, often neglected, probably, due to their little size. There is no doubt that little things perform many important activities in our lives. The literature survey on pond environment studies shows very little investigative works in India; and there is no review publication on pond environment reports. In Europe, pond conservation initiative has, however, resulted in many studies on the subject. In Indian perspectives, when there is a dearth of studies on ponds, it is futile to say that there is any concrete institutional initiative on pond conservation. The 2010-2011 report of the Central Pollution Control Board (CPCB) shows that there are only 60 CPCB pond water quality monitoring stations in the country. In these scenarios, an attempt has been made in this manuscript to compile the reports on pond environment in India. The problems faced by ponds in India, mostly from pollution and encroachment, have been discussed in the text. Based on outcomes of different pond reports, some suggestions have been discussed in the end of the manuscript for an effective pond conservation initiative, and their sustainable management in India.

The Mayurakshi River system is an important interstate river system in India, and is widely exploited for various purposes. A preliminary assessment of the water quality of the Mayurakshi system, at eleven strategically selected locations in the West Bengal (India), was carried out. Most of the water quality parameters were found to be within the regulatory limits of the recommended standards and other indices, including water quality index (WQI). The WQI values varied from 70.45 to 84.09, and designated the Mayurakshi system ecologically in the range of good water quality type. Agglomerative hierarchical cluster analysis (AHCA) grouped the sampling sites into three clusters based on river water utilization criteria: degree of domestic use, agricultural practices, and fisheries. The study showed the utility of AHCA in decreasing the number of sampling sites and increasing the efficacy of continuous monitoring of the Mayurakshi basin. Overall the basin water quality was found ecologically sustainable with limited anthropogenic impact on the river water environment.

Aquatic insects are used as model organisms for assessing the health status of lenthic or lotic ecosystems. Biomonitoring using entomological indicators is one of the widely accepted tools to analyze the impacts of sewages in aquatic environment. The present study was aimed to assess the health status of a semi urban river system, Killiyar using entomological indicators. Season wise sampling of aquatic insects was done at four selected segments according to the rapid bioassessment protocol recommended by Environmental Protection Agency. The present study could identify 29 families of aquatic insects for screening the levels of pollution in Killiyar. Family Biotic Index (FBI) showed that there was a remarkable variation in water quality along the river. Hilsenhoff’s family biotic index obtained for river origin was in the range 4.40 - 5.02 indicating excellent water quality. High value of family biotic index, least occurrence of intolerant groups and dominance of tolerant taxa in the midstream and downstream segments showed that increased contamination of water by various sources. Immediate attention is needed to cease the degradation of this precious ecosystem.      Keywords: Aquatic insects, Biomonitoring, Family Biotic Index, Killiyar, Water pollution