A Study on Planktonic Status of Bansagar Dam,

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I. INTRODUCTION
Planktons exhibit a unity and are characterized by some extreme order lines in the variations of physico-chemical characteristics.Therefore, evaluation of composition of planktonic populations and their diversity and succession are very important aspects in monitoring the productivity and status of a water body.
Zooplanktons are known as heterogeneous assemblage of minute and microscopic floating animals found in natural waters.These organisms usually play role as primary consumers and constitute an important relation between primary producers and higher consumers in aquatic food chains.The zooplanktons consist of a wide array of animal groups but the members of protoza, rotifera, copepoda, cladocera and ostracoda are often found dominating.Gannon and Stemberger (1978) noted the occurrence of rotifera and Cladocera in highly eutrophic lakes.

II. HISTORY
Recently, many workers have studied the hydrobiology of different aquatic resources of India, i.e.Nagamani et al. (2015) analysed the physico-chemical factors of water samples of urban and rural area of Bangalore.Sagar et al. (2015) reported the physico-chemical parameters for testing water.Shrivastava et al. (2015) reported the water quality management plan for Patalganga River for drinking purpose and human health safety, which is located 60 km from Mumbai and is a significant source of water supply for Panvel, Alibaug and Rasayani.Various technical research papers on the assessment of water quality of different areas have been presented Danha et al. (2015) worked on physico-chemical analysis and fish pond conservation in Kano State, Nigeria, Elegbede et al. (2015) reported the effect of water quality characteristics of fish population of the lake Volta, Ghana, Zafar et al. (2015) analysed water and soil quality parameters of shrimp and prawn farming in the southwest region of Bangladesh.Sandhya and Benarjee (2016) worked on physico-chemical properties of some selected fresh water fish ponds in relation to fish production in Warangal area, Telangana State, India.Reda (2016) studied the physico-chemical properties of drinking water quality of Arbamich Town, Ethiopia.Querijero and Mercurio (2016) worked on water quality in aquaculture and non-aquaculture sites in Taal lake, Batangas, Philippines.Kashyap (2016)

Quantitative Analysis
Planktons were enumerated in the laboratory of Govt.Model Science College, Rewa (M.P.) using microscope by drop counting method (APHA, 1985) In this method one drop of the water sample is pipette out from a calibrated pipette on a glass slide and the planktonic organisms were counted in strips.The total area under the cover slip represents the number of organisms present per given volume of the sample.This volume expanded to an appropriate yield the organisms per liter of water for the Bansagar Dam.The results were presented as number of organisms per liter of original collected water sample.The counting of zooplanktons was also done with the help of Sedgwick-Rafter cell method (APHA, 1985).Since, the number of zooplanktons counted by Sedgwick-Rafter cell were related with 1 ml of concentrated sample, therefore, the observed number of zooplanktons were multiplied accordingly to get the results in number of organisms as per in original sample.

IV. RESULTS AND DISCUSSION 4.1 Annual Density of Phytoplankton
The mean annual density of four taxonomic groups of phytoplankton recorded during study period is represented in Table 1a, 1b, 2, 3 and Graph 1. Cynophyceae showed their dominance over the other groups of phytoplankton.The average annual density of Cyanohyceae was recorded as 2234 org/l with percentage contribution of 41.51% followed by Chlorophyceae with annual density of 1906 org/l and percentage contribution of 35.42%, Bacillariophyceae with annual density of 1156 org/l and percentage contribution of 21.48% and Euglenophyceae with annual density of 85 org/l and percentage contribution of 1.57 org/l during study period.
In the present study, a total of 27 phytoplankton species belonging to 27 genera representing 4 major classes were documented which indicate diverse nature of phytoplankton in general as well as of Bansagar Dam (Table 2 and 3).Among 27 species of phytoplankton, 08 belonged to Chlorophyceae, 10 to Cynophyceae, 07 to Bacillariophyceae and 02 to Euglenophyceae.The order of dominance was the Bacillariophyceae > Chlorophyceae > Cynophyceae > Euglenophyceae.Singh (1990) and Pillai et. al., (2011) were studied the variation and distribution of phytoplanktons in different water bodies, Pailwan et. al., (2008) and Baba and Pandit (2014) described the bimodal growth curve in their studies.The mean annual density of five taxonomic groups of zooplankton recorded during study period is represented in Table 4a, 4b, 5, 6 and Graph 2. Rotifera group showed their dominance over the other groups of zooplankton.The average annual density of Rotifera was recorded as 1044org/l with percentage contribution of 47.78% followed by Copepoda with annual density of 1587org/l and percentage contribution of 20.62%, Protozoa with annual density of 1044org/l and percentage contribution of 13.56%, Cladocera with annual density 932org/l 1 and percentage contribution 12.11% and Ostracoda with annual density of 455org/l and percentage contribution of 5.91%.The mean ±SD values of zooplanktons were recorded as 238±174.207org/lat station A, 165±110.967org/l at station B and 218±146.540org/l at station C with a mean value of 207±115.388org/lduring study period Table 4a.The maximum values of zooplanktons were recorded in summer season (328org/l), moderate in rainy season (181org/l) and minimum in winter season (103org/l) during study period (Table 4a,4b,5,6 Graph 2).
The minimum and maximum values of phytoplanktons fluctuated between 61 to 323org/l.The minimum values of phytoplanktons were recorded in the month of August and maximum in the month of April during study period.The mean ±SD values of phytoplanktons were recorded 149±85.875org/lduring study period.The maximum values of phytoplanktons were recorded in summer season (225org/l), moderate in rainy season (122org/l) and minimum in winter season (101org/l) during study period 4.2 Annual Density of Zooplankton

Table 1a :
Mean values of monthly and seasonal variations of Phytoplanktons (org./l) in three sampling stations of Bansagar Dam from November 2014 to October 2015

Table 1b :
Analysis of variance for Planktons.

Table 3 :
Annual density of phytoplankton in Bansagar dam from November 2014 to October 2015: Species composition of different phytoplanktons' group in Bansagar Dam from November 2014 to October 2015.

Table 4a :
Mean values of monthly and seasonal variations of Zooplanktons (org./l/) in three sampling stations of Bansagar Dam from November 2014 to October 2015.

Table 4b :
Analysis of variance for Zooplanktons.

Table 5 :
Genera and species percentage composition of different zooplankton classes in Bansagar Dam.

Table 6 :
Annual density of zooplanktons in Bansagar dam from November 2014 to October 2015: S. No. Taxonomic group Mean annual density (org/l) Nov. 2014 to Oct. 2015 Graph 2: Species composition of different zooplanktons' group in Bansagar Dam from November 2014 to October 2015.