Journal of Environmental Biology ©Triveni Enterprises, Lucknow (India) Free paper downloaded from: www. jeb.co.in September 2008, 29(5) 747-752 (2008) For personal use only Commercial distribution of this copy is illegal Studies on phytoplankton diversity in response to abiotic factors in Veeranam lake in the Cuddalore district of Tamil Nadu R. Senthilkumar and K. Sivakumar* Department of Botany, Directorate of Distance Education, Annamalai University, Annamalainagar - 608 002, India py (Received: September 01, 2006; Revised received: May 15, 2007; Accepted: June 05, 2007) Abstract: The phytoplankton samples were collected from the Veeranam lake for a period of one year from March-2005 to February-2006. The physicochemical parameters of water such as air-temperature, water temperature, pH, salinity, dissolved oxygen, electrical conductivity and total dissolved solids were observed and their ranges were: 30.1-36.5oC, 29.0-34.4oC, 7.9-8.4, 1.2-2.5 mgl-1, 7.6-9.2 µS and 2.5-5.2 mgl-1. Totally 160 species of phytoplankton belonging to different taxonomic groups were identified. Among these 74 species to belong to Bacillariophyceae, 43 species to Chlorophyceae, 38 species to Cyanophyceae and 5 species to Euglenophyceae. The phytoplankton density was high (1705 cells l-1) during the summer season and low (760 cells l-1) during the winter season. Bacillariophyceae formed the dominant group. Species diversity index (H’), species richness (SR) and species evenness (J’) were calculated. Co Key words: Phytoplankton, Physico-chemical parameters, Veeranam lake PDF of full length paper is available with author (*[email protected]) of Chidambaram taluk and southern half of Kattumannarkoil taluk in the Cuddalore district. The lake is being used for multipurpose utility such as irrigation, fish catching washing and bathing. This lake is one of the major water resource supply to the Chennai metropolitan city corporation. The lake covers on water spread 15 sq miles (38.85 sq km) area of length 15 km from North-South, 5 km width from East-West, minimum depth 5.43 m, water storing capacity 45.50, ft = 990 mct (0.99 TMC) (mean sea level), = 990 mct (0.99 TMC) with 34 sluices irrigated land area approximately 45,000 acres. On lin e Introduction The Veeranam Lake is oldest and largest lake of Tamilnadu. This is a very significant lake in south India, and nearly 45,000 acres of agricultural land areas are irrigated by this lake and in addition since-2004 the lake supplies the large quantity of water for Chennai metropolitan city for drinking purpose. Phytoplankton forms the vital source of energy as primary producers and serves as a direct source of food to the other aquatic plants and animals. Assessment of water quality by algal community used for of Harambaeredam and Mossam rivers of Maharashtra were made by Nandan and Ahur (2005). Systematic and ecological studies on Chlorophyceae of North India and their relationship with water quality was made (Dwivedi et al., 2005). Algal biodiversity in fresh water and related physico-chemical factors were studied by Veereshakumar and Hosmani (2006), which dealt substantially for the organic production of waters ways. They will give information about the productivity of the environment. In India, many such lakes and reservoirs have been studied for the water quality and fisheries (Nautiyal et al., 1988; Kartha and Rao, 1992; Pandey, 1993; Ravikumar et al., 2006; Nurulalom and Zaman, 2006; Tiwari and Shukla, 2007; Tiwari and Chauhan, 2006; Sridhar et al., 2006; Tas and Gonulol, 2007). But still there are many such aquatic ecosystems that remains unexplored. The Veeranam lake is one among them which has not received due attention. Hence, the present work is an attempt to study the influence of physico-chemical parameters of water on phytoplankton population, species composition and community organization. History and morphometric of Veeranam lake: The Veeranam lake (Lat. 11o17’N); Long. 79o32’E) is situated in the Cuddalore district of Tamil Nadu state, India (Fig. 1). It was formed by the Prince Rajathithar son of Paranthaga Cholan during the 9th century and as on date its age is 1038 years. The lake is located in the western half Materials and Methods Water samples were collected from Veeranam lake at monthly intervals for a period of one year from March-2005 to February2006 for the analysis of air temperature, water temperature, pH, salinity, dissolved oxygen, electrical conductivity and total dissolved solids. The physico-chemical parameters were analyzed by water and soil analysis kit model 1160-E. Phytoplankton samples were collected by towing a plankton net (mouth diameter 0.35 mm) made up of bolting silk (no.30; mesh size 48 µ) for half an hour. The samples were collected in black polythene bags and immediately preserved with 4% formalin for quantitative and qualitative analysis. Plankton counting was made by drop method. Some of the specimens were fixed in 3% glutaroldehyde in 0.1 M phosphate buffer at (pH 6.8) for scanning electronmicroscopic studies. Specimens were then dehydrated through a graded series of acetone 12-15 min interval at 4oC upto 70% of acetone. Then dehydrated phytoplanktons treated with critical point drier (CPD) were on a stub and the specimens were coated they were examined with Joel JSM-56010 LV with INSA-EDS, photomicrographs were taken selectively from the computer screen (Hayet and Falk, 1980). Phytoplankton was identified by consulting the workers of Desikachary (1959), Prescott (1964), Anand (1998), Cox (1996). Species diversity index (H’) was calculated using Shannon and Weiner’s (1949) and Pielous Journal of Environmental Biology September, 2008 748 R. Senthilkumar and K. Sivakumar Andhra Pradesh Karnataka Pondicherry Bay of Bengal Indian Ocean py Arabian sea India Cuddalore district Tamil Nadu Co (1966) formulae respectively. Species richness (SR) was calculated as described by Simpson index (Simpson, 1949). Sampling stations of Veeranam lake On lin e Results and Discussion Monthly variations in physico-chemical parameters of Veeranam lake are depicted in Table 1. The seasonal variation of productivity is related to variation in temperature and the photic conditions. Similar findings were also reported by Sondergaard and Sand Jensen (1979) and Spencer and King (1989). Temperature is an important factor, which regulates the biogeochemical activities in the aquatic environment. Maximum temperature was recorded during May and June and minimum in September and October. The variation in the water temperature in present investigation may be due to the difference in sampling time and the effect of season (Jayaraman et al., 2003; Tiwari et al., 2004). Water temperature influences aquatic weed, algal blooms (Zafer, 1968) and surrounding air temperature (Gupta and Sharma, 1993). All metabolic and physiological activity and life processes such as feeding, reproduction, movements and distribution of aquatic organisms are greatly influenced by water temperature. The pH varied from 7.9 to 8.4 (alkaline range) with a minimum in August and maximum in April. Wani and Subla (1990), reported that the pH values above 8 in natural waters were produced by photosynthetic rate that demands more CO2 than quantities furnished by respiration and decomposition. pH is one of the most important factors that serves as an index of the pollution. The water body registered an alkaline pH with the values ranging from 7.45 to 8.1 (Ranjan et al., 2007). pH value of majority of lakes and reservoirs in India has been found between 6 to 9. The higher range of pH indicates higher productivity of water (Khan and Khan, 1985). Salinity acts as major ecological factor controlling the phytoplankton population of freshwater as well as brackish water species, which appeared or disappeared depending upon the salinity condition. The range of salinity during the present study was maximum in summer season and minimum in monsoon period. Journal of Environmental Biology September, 2008 Fig. 1: Location map of Veeranam lake The maximum electrical conductivity was observed in January and minimum in May. A sudden rise in conductivity in water during monsoon and post monsoon season indicates addition of some pollutants (Trivedy and Goel, 1984). High value EC designates pollution status of the lake (Kadam, 1990). The maximum dissolved oxygen was recorded in November (monsoon period) and minimum in June (summer). Dissolved oxygen is governed by the Phytoplankton biodiversity in lake 749 Table - 1: Physio-chemical parameters of Veeranam lake during March 2005 to February 2006 Summer Parameters Air-T ( C) Water-T (oC) pH Salinity (gl-1) DO (mgl-1) EC (µS) TDS (mgl-1) Monsoon Post-monsoon Mar. Apr. May Jun. Jul. Aug. Sept. Oct. Nov. Dec. Jan. Feb. 32.1 32.1 8.3 2.3 3.53 7.8 4.0 34.2 32.2 8.4 2.4 3.45 7.8 4.1 36.3 34.3 8.2 2.5 4.01 7.6 5.0 36.5 34.4 8.2 1.7 2.62 8.5 5.2 35.1 33.1 8.2 1.2 3.41 8.5 4.5 34.3 33.1 7.9 1.2 3.47 9.1 4.5 31.0 29.0 8.0 1.2 4.15 8.2 3.5 32.1 29.0 8.1 1.2 4.20 8.5 3.0 32.1 30.1 8.0 1.3 4.34 9.0 3.0 30.1 29.0 8.3 1.3 4.15 9.0 2.8 31.5 30.0 8.4 1.5 4.10 9.2 2.5 32.3 30.3 8.3 1.6 4.07 9.1 2.6 py o Pre-monsoon All the parameters are in triplicate values - DO = Dissolved oxygen, EC = Electrical conductivity, TDS = Total dissolved solids 2000 1.6 [a ] [b ] 1.5 1600 1.4 1200 Co 1.3 800 1.2 400 1.1 1 0 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mar Jan Feb Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Diversity Density 0.8 1 [ c ] [d ] 0.8 0.6 lin e 0.6 0.4 0.4 0.2 0.2 0 0 Mar Apr May Jun Jul Aug Sep Oct Richness Nov Dec Jan Feb Apr Fig. 2: Monthly variations in phytoplankton photosynthetic activity and aeration rate (Gautam, 1993). It appears that the distribution of dissolved oxygen in the reservoir water is governed by a balance between input from the atmosphere, rainfall and photosynthesis and losses by the chemical and biotic oxidations. The values of total dissolved solids in water varied from a minimum of 2.5 mgl-1 (January-2006) to a maximum of 5.2 mgl-1 (June). The highest average value for total dissolved solid might be due to accumulation of the anthropogenic activity which hampered the quality of water. A total of 160 species of phytoplankton were represented by diverse groups Bacillariophyceae (74), Chlorophyceae (43), Cyanophyceae (38) and Euglenophyceae (5). The percentage composition showed marked variation with Bacillariophyceae On Mar May Jun Jul Aug Sep Oct Nov Dec Jan Feb Evenness occupying dominant position of 46.25%. Some species of phytoplankton were observed by scanning electronmicroscopy (Fig. 3) such as (a) and (b) Oscillatoria sancta (higher magnification), (c) and (d) Syndra ulna (upper view), (e) Pinnularia microstauron, f. Nitzschia palea, (g) Stauroneis sp and (h) Cyclotella meneginiyana and population density ranged between 760 and 1705 cellsl -1 (Fig. 2a) with maximum production in summer. Species such as Chlamydomonas globosa, Scenedesmus dimorphus, Pediastrum simplex and Closterium acerosum occurred in all the seasons. During summer season Euglena spirogyra and Phacus acuminatus were observed abundantly. Species diversity of the area ranged between 1.14 and 1.52 (Fig. 2b). The maximum diversity was during post-monsoon Journal of Environmental Biology September, 2008 750 On lin e Co py R. Senthilkumar and K. Sivakumar Fig. 3: Some phytoplankton species as seen under electron microscope a = Oscillatoria sancta (Kuetz.) Gom b = Oscillatoria sancta (Luetz.) Gom (higher magnification) c = Syndra ulna (Nitz.) Ehr. d = Syndra ulna (Nitz.) Ehr. (upper view) Journal of Environmental Biology September, 2008 e = Pinnularia microstauron (Ehr.) Cl. f = Nitzschia palea (Kuetz.) W. Sm g = Stauroneis sp h = Cyclotella meneginiyana (Kuetzing) Phytoplankton biodiversity in lake 751 Table - 2: List of recorded phytoplankton species at Veeranam lake On py 36 C. tumidum Gay 37 Cosmarium botrytis Menegh 38 C. subcostatum Nordst 39 C. depressum (Naeg.) Lund Order: Zygnematales 40 Spirogyra varians 41 Netrium digitus (Ehr.) Itz & Rothe 42 Staurastrum hexaserum (Ehr.) Wittr. 43 Euastrum insulare (Wittr.) Roy Cynophyceae Order: Chroococcales 1 Microcystis flos-aquae (Wittr.) Kirchner 2 Aphanocapsa litroralis Hansgirg 3 A. banaresensis Bharadwaja 4 A. pulchra (Kuetz.) Rabenh 5 A. grevillei (Hass.) Rabenh 6 Chroococcus disperses (V. Keissler) Lemm. 7 C. tenax (Kirchn) Hieron 8 C. prescottii Drouet & Daily 9 C. turgidus (Kuetz.) Naeg. 10 Gloeocapsa magma (Breb.) Kuetz. 11 G. nigrescens Naeg. 12 Synechocystis aqualis Saun 13 S. crassa Woromich 14 Polycystis aeruginosa Naeg 15 P. incerta 16 Synechococcus aeruginosus Naeg. 17 Merismopedia elegans G.M. Smith 18 M. glauca (Ehr.) Naeg. 19 Tetrapedia reinschiana 20 Coeolophaerium dubium Grun 21 Gomphosohaeria aponina (Kuetz.) 22 Marssoniella elegans Lemm. Order: Hamaesiphonales 23 Mixosarcina amethystine J.J. Copeland 24 Stichosiphon regularis Geitler. Order: Oscillatoriales 25 Spirulina major (Kütz) Gomont 26 S. meneghiniana Zanard ex Gomont 27 S. princeps West. et West 28 S. subsalsa Oerst. ex Gom. 29 Oscillatoria subbrevis Schmidle F. Crassa 30 O. curviceps Ag. ex Gomont 31 O. chlorina Kuetz. ex Gomont 32 Arthrospira platensis (Nordst) 33 A. jenneri Stizenb. et Gomont Order: Nostocales 34 Anabaena spiroides Klebahn 35 A. circinalis Robenhorst ex Born et Flah. 36 A. constricta 37 Nostoc pruniforme Ag. 38 N. carneum Ag. ex Born et. Flah Euglenophyceae 1 Euglena spirogyra Ehr. 2 E. viridis Ehr. 3 Phacus acuminatus Stokes 4 P. longicauda Ehr. 5 P. pleuronectes Dujardin Co 57 C. alpina Grun 58 C. turgida (Greg) Cleve 59 C. cymbiformis Kuetz. 60 C. tumida (Breb.) 61 Nitzschia vitrea Norman 62 N. plana Wm. Sm. 63 N. amphibia Grun 64 N. palea (Kuetz.) 65 N. palaceae (Kuetz.) 66 Nitzschia brebissonii W. Smith 67 Gyrosigma acuminatum (Kuetz.) Rabh. 68 Neidium iridis (Ehr.) Pfitzer 69 Tabellaria fenestrata 70 Melosira granulata (Ehr.) Ralfs 71 Stauroneis parvula var. Prominula Grun 72 Surirella elegans Ehr. 73 Eunotia pectinalis (Kuetz.) Rabenh. 74 E. monodon Ehr. Chlorophyceae Order: Volvvocales 1 Chlamydomonas globosa Snow. 2 C. fasciata 3 C. reinhardi (Dang) 4 C. polypyrenoideum Presc. 5 Pendorina morum Bory 6 Eudorina elegans Ehr. 7 Haematococcus lacustris (Girod.) Rostaf. 8 Palmella miniata Lieb. 9 Tetraspora lubrica (Roth) Ag. 10 Chlorosarcina consociate (Klebs) G.M. Smith Order: Chlorococcales 11 Coleochaete suluta (Breb.) Pringsheim 12 Chlorococcum humicola (Naeg.) Rabenh 13 Coelastrum microporum Naeg. 14 Chlorella ellipsoidea Gerneck. 15 C. protothecoids 16 C. vulgaris Beyernick 17 C. pyrenoidosa Chick 18 Westella botryoides (W. West) 19 Ankistrodesmus falcatus (Corda) Ralfs 20 Selenastrum gracile Reinsch 21 S. biraianum Reinsch 22 Tetraedron trigonum (Naeg.) Hansg 23 Scenedesmus quadricauda (Turp.) Breb. 24 S. dimorphus (Turp.) Kuetz. 25 S. bijiuga (Reinsch) 26 S. armatus (Chodat) Smith 27 Pediastrum boryanum (Turp.) Menegh 28 P. biradiatum Presc. 29 P. simplex Meyen 30 P. tetras (Ehr.) Ralfs 31 P. duplex Meyen Order: Cladophorales 32 Cladophora crispate (Roth) Kuetzing 33 C. glomerata (L.) Kuetz. Order: Conjucales 34 Closterium acerosum (Schrank) Ehr. 35 C. purvulum Nageli lin e Bacillariophyceae Order: Centrales 1 Cyclotella meneghiniana Kuetzing 2 C. stelligera c.l.u. Grun 3 Sceletonema costatum (Grev.) Cleve 4 Chaetoceros orientalis Schiller 5 Thalassiosira marginata Sp. Nov. Order: Pennales 6 Fragillaria brevistriata Grun 7 F. ratonensis Grun 8 F. intermedia Grun 9 Synedra ulna (Nitz) 10 Mastogloia exigua Lewis 11 M. dolosa Venkataraman 12 M. brauni Grun 13 M. smithii Thwaites 14 M. apiculata Wm. Sm. 15 Achnanthes hauckiana Grun 16 A. inflata Kuetz. 17 Cocconeis placentula Cleve 18 Diploneis subovalis Cleve 19 D. ovalis (Hilse) 20 D. interrupta (Kuetz.) 21 Anomoeneis sphoerophora (Kuetz.) 22 A. serians (Breb.) Celve 23 Stauroneis anceps Ehr. 24 Navicula cuspidate Kuetz. 25 N. peregrina Kuetz. 26 N. lacustris Greg 27 N. cincta Kuetz. 28 N. rostellata Kuetz. 29 N. laterostrata Hust 30 N. radiosa Kuetz. 31 N. pycmae Kuetz. 32 N. rectangularis Kuetz. 33 N. acicularis Kuetz. 34 N. capitatoradiata Kuetz. 35 N. mutica Kuetz. 36 N. hasta Pant. 37 Pinnularia gibba Ehr. 39 P. acrosphoeria Breb. 40 P. interrupta W. Smith 41 P. braunii (Grun) 42 P. viridis (Nitzsch) Ehr. 43 Amphora coffoeformis Ag. 44 A. ovalis Kuetz. 45 Gomphonema intricatum (Kuetz.) 46 G. lanceolatum Ehr. 47 G. parvulum (Kuetz.) 48 G. vibrio Ehr. C.G. Augur Ehr. 49 G. herculeana (Ehr.) Cleve 50 G. acuminatum Ehrench 51 Calonies silicula (Ehr.) Cleve 52 Actinella punctata Lewis 53 Frustulia rhomboids (Ehr.) De Toni 54 Pleurosigma delicatulum W. Smith 55 P. salinarum Grun 56 Cymbella naviculiformis Auersward Journal of Environmental Biology September, 2008 752 R. Senthilkumar and K. Sivakumar The population condition was stable during the months of April and May. The density slowly declined during June and premonsoon period and the lowest value was observed during the month of December-2005. In the present study, the phytoplankton production was coinciding with the optimum water depth of 1 m. This is an agreement with the earlier works of Sukumaran and Das (2001) in some freshwater reservoir of Karnataka. 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The ranges of species richness and evenness were: 0.45-0.60 and 0.57-0.76 respectively (Fig. 2c, 2d). The population density trend showed gradual increase during post-monsoon and summer season and attained the peak during the month of April2005 which was due to nutrient richness and the moderate temperature (Sukunan, 1980).
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