Received Date: December 21, 2015; Accepted Date: February 06, 2016; Published Date: February 08, 2016
Citation: Dwivedi AC, Mishra AS, Mayank P, Tiwari A (2016) Persistence and Structure of the Fish Assemblage from the Ganga River (Kanpur to Varanasi section), India. J Geogr Nat Disast 6: 159. doi:10.4172/2167-0587.1000159
Copyright: © 2016 Dwivedi AC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Visit for more related articles at Journal of Geography & Natural Disasters
Fish assemblages are an important component of aquatic ecosystems. Present investigation was undertaken to study the Persistence, structure and abundance of fishes from the Ganga river (site 1: Kanpur, site 2: Allahabad and site, 3: Varanasi section), India. The Ganga river is a back bone of Indian fishery. The samples were collected monthly during the period June 2011 to May 2013. Canonical correspondence analysis (CCA) indicated that axis 1 and 2 accounted for 67% and 33% variance for species and environmental relation, respectively. Structure of the fish assemblage of the Ganga at Kanupr to Varanasi harbors of 102 fish species belong to 8 orders and 28 families. 74, 89 and 82 fish species were recorded at Kanpur, Allahabad and Varanasi sites, respectively. Cypriniformes and Cyprinidae were the most rich fish species order and family in all sites. At total stretch, Cypriniformes order was shared 49 species, followed by Siluriformes 26 species and Perciformes 17 species. Orders Clupeiformes shared 5 species. Abundance was dominated by Eutropiichthys vacha compared to Clupisoma garua and Sperata seenghala. According to abundance, Cyprinus carpio var. communis (9.64%) and Oreochromis niloticus (9.19%) were powerfully invader in the Ganga river. Exotic species is alarming for indigenous species biodiversity. C. carpio var. communis and O. niloticus are frequently recorded in the Ganga river. Total hardness, alkalinity and dissolved oxygen were responsible for the presence of Catla catla, Rita rita and Sperata aor, while Labeo calbasu, Cyprinus carpio and Cirrhinus mrigala preferred nitrate, phosphate and total dissolved solid for their abundance. Oreochromis niloticus preferred high biological oxygen demand and lead while Zn and Sulphate were responsible for abundance of L. rohita. For conservation point of view C. carpio var. communis and O. niloticus species should be monitored in the Ganga river. Both species are very harmful for fish biodiversity in the Ganga river. Fish assemblage and their abundance know the health of ecosystem.
Fish assemblage; Exotic fish species; Abundance; Ganga river; India
Freshwater fishes are important and valued property for income, human food, sport and ornament. Overexploitation occurs around the world with the use of more and more refined fishing equipment, and the decrease of many fish stocks has been documented as a result of expanding fisheries [1,2]. Illegal fishing using dynamite, pesticides, electrofishing, etc. are also major threats to fish biodiversity all over the world .
Fish assemblages are recognized as responsive indicators of habitat degradation, natural condition degradation, environmental contamination, and overall ecosystem productivity. Freshwater fishes are the most imperiled vertebrate group with a projected extinction rate of five times that of terrestrial fauna and three times that of marine mammals [4-6]. The world natural fishery systems are collapsing as a direct result of overfishing and overcapacity of fishing fleets [7,8]. Biodiversity is essential for stabilization of ecosystem, protection of overall environmental quality for understanding intrinsic worth of all species on the earth . Biodiversity of fishes are suffering day by day in 21th century. Main regions are availability of water in river/stream (for shelter), water abstraction, industries and private use [10,11], habitat destruction and defragmentation [12,13], pollution level , introduction of alien/exotic species  and impacts of global climate changes specially rainfall [16,17]. Distribution patterns of organisms are controlled by dispersal mechanism, historical factors (connecting pathways, dispersal barriers) and tolerance to environmental factors [18,19].
Biodiversity is the quantity, variety and distribution across biological scales ranging through genetics and life forms of populations, species, communities and ecosystems . Biodiversity affects the capacity of living systems to respond to changes in the environment, underpins ecosystem function and provides the ecosystem goods and services that support human well-being (e.g., nutrient cycling, clean water) [21,22]. Fragmented information is available of the fish fauna in the Ganga river by Sinha et al.,  Lakra et al.,  Montana et al.,  and Nautiyal et al., . This section (Kanpur to Varanasi section) of the river is middle stretch which is most important for fisheries and human interference. But no information is available on Canonical Correspondence Analysis (CCA) in the Ganga river especially from Kanpur to Varanasi section, India (Map 1).
The objective of the present study was to give Canonical Correspondence Analysis (CCA) of the Ganga river at Kanpur to Varanasi section, aiming to contribute a better knowledge to structure of the fish assemblage and abundance of commercially important fishes from the Ganga river and a tool for conservation planning of aquatic environments in this region.
The samples were collected monthly during the period August 2012 to July 2013 from the three sites of the Ganga river namely Kanpur (Latitude- 260 27’ 16” N, Longitude- 800 20’ 58”), Allahabad (Latitude- 250 45’ 27” N, Longitude- 810 59’ 31”) and Varanasi (Latitude- 250 19’ 01” N, Longitude- 820 58’ 15”). Present stretch is about 370 km. Human activities and industrial influent maximum reported in these sites of the river. The Ganga river is a holy river of India and has been declared as a national river by the government of India. The Ganga is a perennial river which originates as a stream called “Bhagirathi” from Gaumukh (Himalaya) in the Gangotri glacier at 30° 55' N, 79° 7' E, some 4100 m above mean sea level. Ganga river basin is the largest river basins in India and the fourth largest in the world, with a basin (catchment area) covering 8, 61,404 sq km. It has a total length of 2525 km with two countries (India and Bangladesh). It is backbone for irrigation, agriculture, industrials purpose and fisheries point of view.
Canonical correspondence analysis and related methodology has found wide-spread use in aquatic sciences. Canonical Correspondence Analysis (CCA version 4.5) was used to examine the factors response for the abundance of fish abundance .
The collected samples were preserved in 10% formalin and brought to the laboratory for further study. The fish was identified using Day , Talwar  and Jayaram  books and standard keys. The meristic and morphometric characters collected fishes were measured and counted and identified up to the species level.
The relative abundance was estimated only for commercially and economical important fishes, which preferred by consumer. The relative abundance of individual species was calculated by the following formula:
Canonical correspondence analysis (CCA)
We analyze data in all three sites as a whole stretch because we estimated a comply results for all sites. A CCA diagram does not need to contain all the elements (species, sites, environmental variables). To avoid overcrowding of points, species and sites are often shown in separate diagrams that can, in principle, be overlain. Alternatively, selected points or variables are displayed. Canonical correspondence analysis (CCA) indicated that axis 1 and 2 accounted for 67% and 33% variance for species and environmental relation, respectively. The biplots metrics generated for all three stations by CCA, suggested that total hardness was most important factor at axis 1, while Nitrate and Phosphate were also important at the same axis. At axis 2, pH was most important factor followed by dissolved oxygen, water temperature and Zink metal (Table 1). These variables were correlated significantly (p=0.6660, F-value=0.67) for axis 1 and 2. Total hardness, alkalinity and dissolved oxygen were responsible for the presence of Catla catla, Rita rita and Sperata aor, while Labeo calbasu, Cyprinus carpio and Cirrhinus mrigala preferred nitrate, phosphate and total dissolved solid for their abundance. Oreochromis niloticus preferred high biological oxygen demand and lead while Zn and Sulphate were responsible for abundance of L. rohita (Figure 1).
|Axis variables||Correlation coefficient|
|Total Dissolved Solid (mgl-1)||0.5334||-0.8459|
|Total Hardness (mgl-1)||-0.9966*||0.0828|
|Dissolved Oxygen (mgl-1)||-0.3241||0.9460*|
|Biological Oxygen Demand (mgl-1)||-0.8142||-0.5806|
Table 1: Canonical correlation matrix with two axis of the environmental variables in the canonical correspondence analysis (CCA) for three sites in the river Ganga.
Ordination analysis revealed that environmental variables influence substantially the fish fauna in the Ganga river; total hardness, nitrate, phosphate, DO, pH and water temperature and Zn metal were most important variables for the abundance of L. rohita, L. calbasu, C. catla, C. mrigala, R. rita and C. carpio. O. niloticus was heavy metal preferred fish. Environmental conditions influence fish distributions, communities and seasonal movements. To minimize energy expended for survival, species typically favor areas that optimize their physiological processes . Moyle et al. , Bain et al. , Lobb et al.  also reported water depth, current velocity and substratum as important factor for the abundance of R. alburnoides and L. pyrenaicus in the American rivers.
Structure of the fish assemblage
Fish assemblages in the Ganga river network are influenced by both restricted habitats and larger landscape patterns and water management system. Major local factors are 1) availability of different types of habitats condition, 2) availability of different types of food organisms and resources, and 3) interactions with other aquatic species (e.g., predation, competitive interactions). About half of Indian fishes are in the minnow family (Cyprinidae). During the study period different fish varieties have been recorded in the Ganga river at Kanpur, Allahabad and Varanasi sites, India. Human activities and industrial influent maximum reported in these sites of the river, so we have chosen these sites. The result showed that the area was rich in fish diversity. Fish biodiversity of the Ganga river from Kanupr to Varanasi harbors of 102 fish species (with variety) belong to 8 orders and 28 families (Table 2). Cypriniformes and Cyprinidae were the most rich species order and family. At total stretch, Cypriniformes order was shared 49 species (48.04%), followed by Siluriformes 26 species (25.49%) and Perciformes 17 species (16.67%). Orders Clupeiformes shared 5 species (4.90%) (Figure 2).
|6||Tenualosa (Hilsa) ilisha||+|
Table 2: Biodiversity of fishes from the Ganga River at Kanpur to Varanasi, India.
At Kanpur site, 74 fish species were recorded with 6 orders. Cypriniformes order was shared 32 species (43.24%) followed by Siluriformes 21 species (28.38%) and Perciformes 15 species (20.27%). Order Clupeiformes shared 3 species (4.05%) (Figure 3). At Allahabad site, 89 fish species were recorded with 8 orders. Cypriniformes order was shared 41 species (46.07%) followed by Siluriformes 25 species (28.09%) and Perciformes 14 species (15.73%). Order Clupeiformes and Osteoglossiformes shared 4 species (4.49%) and 2 species (2.25%), respectively (Figure 4). At Varanasi site, 82 fish species were recorded with 7 orders. Cypriniformes order was shared 39 species (47.56%) followed by Siluriformes 23 species (28.05%) and Perciformes 13 species (15.85%). Order Clupeiformes and Osteoglossiformes shared 3 species (3.66%) and 2 species (2.44%), respectively (Figure 5). Cyprinus carpio var. communis and Oreochromis niloticus are frequently recorded in the Ganga river. Both species had large dispersal capacity. Both species are exotic/alien fish species for India. For conservation point of view C. carpio var. communis and O. niloticus species should be monitored in the Ganga river. Both species are very harmful for fish biodiversity in any large water bodies as like rivers, lakes and reservoirs. Fishes are threatened by channelization of rivers/streams beds.
More species are needed to insure a stable supply of ecosystem goods and services as spatial and temporal variability increases, which typically occurs as longer time periods and larger areas are considered . Each natural habitat has a variety of species, which differ in their relative abundance. No community consists of species of equal abundance. Some species are rare, others are common and still others may be abundant . Nautiyal et al.  recorded 122 fish species from the Ganga river (Haridwar to Kanpur section). Menon  has listed 207 species of fish from the Gangetic plains which belong to 29 families and 82 genera. According to another estimate, the Gangetic system alone harbours not less than 265 species of fish . Freshwater biodiversity has declined faster than either terrestrial or marine biodiversity over the past 30 years [37,38]. Introductions of non-indigenous fishes can reduce diversity and modify local community dynamics in freshwater systems . The physical and biological characteristics of riverine systems have been shown to shape fish community .
Abundance of some important fishes
Abundance was recorded only commercially important fish species, which preferred by consumer and had high market price. Out of 102 species, species having higher economic value are C. catla, L. rohita, C. mrigala, L. calbasu, S. aor, S. seenghala, W. attu, R. rita, E. vacha. C. garua and C. carpio var. communis and O. niloticus had moderate economic value. C. catla, L. rohita, C. mrigala, L. calbasu are herbivorous in feeding while S. aor, S. seenghala, W. attu, R. rita, E. vacha. C. garua are carnivorous in feeding. C. carpio var. communis and O. niloticus are omnivorous in feeding.
Canonical correspondence analysis confirmed statistically highly significant differences (P<0.0001) between fish abundance of the individual site. In total, 21.2% of fish assemblage variability is explained by this pattern, as it roughly summarises differences in environmental conditions of individual site. C. carpio var. communis and O. niloticus both species are invader species in the Ganga river. According to pooled abundance E. vacha was dominated fishes in the total stretch from the Ganga river. Indian major carp abundance was poor at present work. Catfishes were dominated in carp groups. Abundance of exotic species was also very high. At Kanpur site, S. seenghala (15.76%) was dominated compared to C. garua (14.67%) and E. vacha (13.95%). Its appeared 2.32%, 3.56% and 4.55% of C. catla, L. rohita and C. mrigala, respectively. C. catla, L. rohita and C. mrigala abundances were strongly correlated with temperature. At Allahabad site, E. vacha (18.69%) was dominated compared to C. garua (17.00%) and S. seenghala (15.17%). At Varanasi site, E. vacha (20.19%) was dominated compared to C. garua (19.09%) and S. seenghala (14.94%). Present study indicated that the O. niloticus strongly associated with high biological oxygen demand and lead. Lakra et al.  observed relative abundance 1.33, 2.75, 1.21 and 0.34 of C. catla, L. rohita, C. mrigal and C. carpio from the Betwa river. O. niloticus and C. carpio powerfully invaded in the Ganga river [15,41] and its largest tributary the Yamuna river . Exotic species may become invasive and are capable of spreading exotic diseases, decreasing biodiversity through competition, predation and habitat degradation, genetic deterioration of wild populations through hybridization and gene introgression in short or long course of time [42,43].
The authors are highly thankful to Head of Central Inland Fisheries Research Institute (ICAR), Allahabad for providing laboratory facilities and suggestion.
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals