Time Scale Changes in the Water Quality of the Ganga River, India and Estimation of Suitability for Exotic and Hardy Fishes

Abstract

The water quality of rivers is an issue of serious concern today. Rivers are heavily impacted due to their use for carrying off the industrial, municipal, agricultural and domestic effluents. Water samples were collected for the present study from the Ganga River at Kanpur, Allahabad and Varanasi sites, during the period 2011-2012. The minimum temperature (17°C) was recorded in winter season. The pH, TDS, EC, sulphate, phosphate, nitrate, BOD and COD values exhibited their minimum at Allahabad site. The chloride and dissolved oxygen were recorded minimum at Kanpur site while alkalinity and total hardness had their lowest values at Varanasi site. The water quality of the Kanpur site was very poor compared to Varanasi and Allahabad sites. However, the Ganga river waters could host some tolerant fish species such as the exotic Cyprinus carpio and Oreochromis niloticus and also catfishes. All these species are very hardy, in respect of poor water quality, thus they (exotic species) have powerfully invaded in degraded systems worldwide.

Biodiversity: The Non-natives Species Versus the Natives Species and Ecosystem Functioning

“…Ecosystem functioning has also been affected by altering the size composition in functional sets. These fishes have developed their own strategy to survive with the poor water quality [69][70][71][72].…”

“…When too many species of the aquatic system have been losted, after that the ecosystem would be changed and would function in its own specialized behavior with the relation of ecosystem and remaining organisms. Individual species are as important for ecosystem processes as are mélange of species [32,71]. O. niloticus has modifying trophic web structure through competing with other indigenous fish and preying on juveniles of fishes [73,74], has stated along with evidence that there is a direct relationship between biodiversity and ecosystem functioning.…”

Invader Potential and Population Structure of Non-Native Fish Species, Cyprinus carpio with Respect of Climate from the Vindhya Region, India

“…The key scales were collected from the region just below the dorsal fin (3-4 rows) and above the lateral line and were thoroughly washed in tap water until all extra matter got completely removed and mounted intact in between two glass plates. The ring formation was determined according to the criterion suggested [6,7,18,19]. Almost all the annuli, except the one, appeared as light relatively transparent bands, concentrically arranged around the whole of the anterior sculptured part of the scales.…”

“…It is the only fish which has perhaps a globally distribution since the current century [4,5]. It is a hardy fish that is well suited for aquaculture and fast growing fish [6]. It dwells in lower reaches of rivers and shallow confined waters with slow flowing or standing water and soft bottom sediments [7,8].…”

“…It forms most productive fishery (riverine) in Central India with Oreochromis niloticus [10][11][12][13][14]. Their ability to thrive in new water bodies has caused many ecosystem management problems [15][16][17]. Common carp makes the most acceptable warmwater fish for commercial fish culture [15].…”