The Ganges basin fish Cirrhinus mrigala (Cypriniformes: Cyprinidae): detection of wild populations stock structure with landmark morphometry

Cirrhinus mrigala (Hamilton, 1822) is an Indian major carp originally inhabitant of the Ganga river system in Northern India. No information is available on morphometric variation in natural populations of C. mrigala from Ganga river basin. Therefore, to promote management optimization, this study was undertaken to evaluate the population structure on landmark-based morphometric variations of this commercially important species in Ganges. A total of 381 fish samples of C. mrigala were collected from 10 locations of 10 rivers belonging to Ganges basin. A 12-landmark truss network system was used to generate 66 morphometric variables were transformed (standard length was excluded from the final analysis retaining 65 variables). Transformed measurements were employed to univariate analysis of variance, principal component analysis (PCA) and discriminant function analysis (DFA). Univariate analysis of variance showed significant differences in all the 65 transformed morphometric characters studied. Eight principal components were extracted from 65 significant characters accounting for 94.1 % of the variation. Forward stepwise discriminant function analysis of the 65 significant variables produced eight discriminating variables. DFA extracted eight discriminating functions contributed overall to the variance. The first discriminant function (DF) accounted for 37.9 % while second DF accounted for 23.5% of the among-group variability. In DFA, 45.7 % original while 39.1 % of cross-validated grouped cases were correctly classified in the overall assignment of individuals, indicating low distinction among the stocks of all the species i.e. low isolation of the stocks for the morphometric measurements. Common ancestry in the prehistoric period and migration of individuals between the rivers could be the possible reason for the observed low level of morphometric differentiation among wild mrigal populations. In future, the application of molecular genetic markers along with morphometric studies would be an effective method to examine the genetic component of phenotypic relatedness between geographic regions and to facilitate the development of management recommendations.

Cirrhinus mrigala es una carpa originaria del sistema fluvial del río Ganges al norte de India, de cual no hay información sobre la variación morfométrica de sus poblaciones naturales en esta cuenca. Por lo tanto, para promover la optimización de su manejo, se evaluó la estructura poblacional usando morfometría basada en puntos de referencia de C. mrigala. En total se midieron 381 individuos de C. mrigala, recolectados en 10 puntos de 10 ríos de la cuenca del Ganges. Se utilizaron 12-puntos de referencia de sistema de redes truss para generar 66 variables morfométricas, de donde se excluyó la longitud estándar y se utilizaron 65 variables. Las medidas transformadas se utilizaron para un análisis de varianza univariado, análisis de componentes principales y análisis de función discriminante. El análisis de varianza mostró diferencias en todos los 65 caracteres morfométricos estudiados. Se extrajeron ocho componentes principales de los 65 caracteres, que suman el 94.1 % de la variación. El análisis de función discriminante de las 65 variables produjo ocho variables discriminantes que contribuyeron en la varianza a nivel general. La primera función discriminante representó 37.9 %, mientras que la segunda 23.5 % de la variación entre grupos. En el análisis de función discriminante, 39.1 % de lo agrupado por validación cruzada fue correctamente clasificado en la asignación general de individuos, lo que indica baja diferenciación entre las poblaciones, lo que puede ser un bajo aislamiento de las poblaciones para las medidas morfométricas. Otra posible razón para la baja diferenciación morfométrica es la existencia de un ancestro común en el periodo prehistórico y la migración de individuos entre ríos. En el futuro, la aplicación de marcadores genéticos moleculares junto con estudios morfométricos será un método efectivo para examinar el componente genético de la relación fenotípica entre áreas geográficas y facilitar el desarrollo de recomendaciones de manejo.

The Physiochemical, Biological Quality and Seasonal Variability of River Ganges in Varanasi, Uttar Pradesh, India

Background: The Ganga River is a life-line, a symbol of purity and virtue for countless people of India. Nearly all the sewage, industrial effluent, runoff from chemical fertilizers and pesticides used in agriculture within the basin, and large quantities of solid waste, including thousands of animals carcasses and hundreds of human corpses are dumped in the river everyday which posed a considerable public health threat to the religious bathers and a large number of people living along the river who uses Ganges water for drinking and other household purposes. Objective: To assess the physiochemical and biological quality of river Ganges water and to study the seasonality pattern of pollution of River Ganges. Materials and Methods: Two points namely Samne ghat and Rajghat (entry and exit point of Ganga into the city) were selected as the first and the last sampling stations, beside 8 other intermediate sampling stations to assess the physiochemical and biological quality of River Ganga water. The study was conducted from April 2013 to March 2014 and this period was crudely divided into three seasons viz Winter, Summer and Rainy season for the purpose of studying seasonality pattern of pollution. Results: As the river progress through city of Varanasi, Total dissolved solids (TDS), Chloride, Conductivity, Biochemical Oxygen Demand (BOD), Nitrate, Nitrite and Most Probable Number (MPN) increases, DO decreases progressively and Temperature and pH remain same. Conclusion: As far as quality of water with regard to recreational and industrial purposes are concerned, Ganges water may be considered useful but most of the parameters observed across different seasons indicates that it may not be used as potable water.

Assessment of Leachate Pollution Index and Greenhouse Gas Emission at MSW Dumpsites along Ganga River at Varanasi, India.

Recent scientific attention has shown serious concern towards municipal solid wastes (MSW) as a source of greenhouse gases and concentrated leachate. We studied the leachate pollution index (LPI) and emission fluxes of two greenhouse gases (CH4 and CO2) at two municipal solid waste dumpsites situated along the Ganga River at Varanasi (India). The LPI is a quantitative tool by which the leachate pollution data of dumping sites can be reported uniformly. Concentration of nutrient ions (Ca2+, Mg2+, Na+, K+, NO3 -, Cl-, PO4 3- ) and heavy metals (Cd2+, Fe2+, Cu2+, Pb2+, Ni2+ ,Zn2+, Co2+, Mn2+ ) in leachate varied with season with values being highest in rainy season. Total dissolved solids, conductivity and salinity in leachate showed a similar trend. Leachate pollution index was found to be 87.19 and 82.56 at KZP and BPS sites respectively. The LPI was much higher than the permissible limit at both the sites indicating high contamination potential for surface and ground water and risk to human health. Among all the study metals, Pb was found in abundance at Site 1. The emission flux of CH4 ranged from 10.73 to 96.74 mg m-2 h-1 and that of CO2 from 17.28 to 321.89 mg m-2 h-1. Emission flux of both the greenhouse gases increased with rising moisture and temperature. The rates were higher at young landfill site and between-site differences in the emission of CH4 and CO2 were significant. The study has relevance establishing landfill associated contamination to Ganga River and reducing uncertainties in greenhouse gas emission estimates in India.