ABSTRACT
Investigations were carried out on the diversity of phytoplankton in relation to physico-chemical parameters with respect to pollution status of two perennial ponds of Sattur area, Tamil Nadu. Fifty species were identified belonging to Chlorophyceae, Bacillariophyceae, Cyanophyceae and Euglenophyceae. High value of physico-chemical parameters and low phytoplankton diversity were recorded in the Chinnapperkovil pond, whereas low value of physico-chemical parameters and high phytoplankton diversity were recorded in the Nallanchettipatti pond. Class Chlorophyceae qualitatively and quantitatively dominated in both the habitats when compared to other taxa. Present study revealed that phytoplankton species richness (R1 and R2) was comparatively higher (R1: 5.43±0.53; R2: 3.00±0.27) in Nallancheettipatti pond. The species diversity was high (H’: 3.08±0.37; N1: 14.05±0.63; N2: 12.55±0.94) in Nallanchettipatti pond compared to Chinnapperkovil pond (H’: 2.25±0.15; N1: 12.59±0.80; N2: 8.54±0.61). Anabaena aequalis, Nitzschia bilobata, Navicula membranacea, Scenedesmus annatus, Pediastrum leonensis, Frustulia rhomboides, Microcystis aeruginosa, Oscillatoria angusta, Closterium acerosum species dominated in Chinnapperkovil pond and Spirogyra maxima, Zygnema caeruteum and Fragilaria oceanica dominated in Nallanchettipatti pond. Abundance of such specific taxa (e.g. Closterium acerosum, C. dianae, C. lineatum, Anabaena aequalis, Oscillatoria angusta and Navicula membranacea) in the Chinnapperkovil and Nallanchettipatti (e.g. Merismopedia glauca and Fragilaria oceanica) ponds suggests that these taxa can be considered as pollution indicators. Phytoplankton species diversity and physico-chemical parameter profiles indicate the Chinnapperkovil pond to be meso-eutrophic whereas the Nallanchettipatti pond is oligo-eutrophic.
ABSTRACT
Plankton diversity and physico-chemical parameters are an important criterion for evaluating the suitability of water for irrigation and drinking purposes. In this study, we tried to assess the zooplankton species richness, diversity, and evenness and to predict the state of three perennial ponds according to physico-chemical parameters. A total of 47 taxa were recorded: 24 rotifers, 9 copepods, 8 cladocerans, 4 ostracods and 2 protozoans. More number of zooplankton species were recorded in Chinnapperkovil pond (47 species) followed by Nallanchettipatti (39 species) and Kadabamkulam pond (24 species). Among the rotifers, Branchionus sp. is abundant. Diaphanosoma sp. predominant among the cladocerans. Among copepods, numerical superiority was found in the case of Mesocyclopes sp. Cypris sp. repeated abundance among ostracoda. Present study revealed that zooplankton species richness (R1 and R2) was comparatively higher (R1: 4.39; R2: 2.13) in Chinnapperkovil pond. The species diversity was higher in the Chinnapperkovil pond (H’: 2.53; N1: 15.05; N2: 15.75) as compared to other ponds. The water samples were analyzed for temperature, pH, electrical conductivity, alkalinity, salinity, phosphate, hardness, dissolved oxygen and biological oxygen demand. Higher value of physico-chemical parameters and zooplankton diversity were recorded in Chinnapperkovil pond as compared to other ponds. The zooplankton population shows positive significant correlation with physico-chemical parameters like, temperature, alkalinity, phosphate, hardness and biological oxygen demand, whereas negatively correlated with rainfall and salinity. The study revealed that the presence of certain species like, Monostyla sp., Keratella sp., Lapadella sp., Leydigia sp., Moinodaphnia sp., Diaptomus sp., Diaphanosoma sp., Mesocyclopes sp., Cypris sp. and Brachionus sp. is considered to be biological indicator for eutrophication.