Studies on ecology of phytoplankton from Pichavaram mangroves, South East Coast of India

The spatial and seasonal distribution of phytoplankton species and their abundance to hydrographical parameters were studied during April 2000 and March 2001 from two stations of Pichavaram mangroves located in south east coast of India, (Lat. 11°27’N: Long 79°47E).  During the study 91 species of phytoplankton were recorded which belongs to different groups viz. Diatoms (73), Dinoflagellates (17) and Slicoflagellates (1). Species such as Coscinodiscus centralis, Pleurosigma elongatum, Thalassionema nitzschioides, Skeletonema costatum Triceratium favus, Odentella sinensis, Navicula longa and Ceratium furca Constituted bulk of the population density.  More number of species was recorded at station 1 and the production of phytoplankton was very high during summer season. The temperature, salinity, pH and dissolved oxygen examined fairly stable during the study period except monsoon. During the summer season nutrients level was low as well as the phytoplankton density was very high

Biodiversity assessment of sea grass ecosystem in ecologically sensitive area for conservation, Kudankulam coast, Southeastern India

The sea grass ecosystems of Gulf of Mannar southern part are still mostly unexplored. The present study has been carried out with the objective of assessing the Sea grass resources of Kudankulam coastin two ecologically sensitive areas during October 2011 to March 2012. Assessment was made in two sites and totally 80 quadrates were selected and studied for the following parameters, species composition, biomass, shoot density, shoot epiphytes cover and epiphytes biomass. Totally five species were found, they are; Thalassiahemprichii, Syringodiumisoetifolium, Cymodoceaserrulata, Halophilaovalis and Haloduleuninervis. The species Thalassiahemprichiii was found to be a dominant one among the total species survived. The overall density of the Sponges are 17.5 followed by Echinoderms 16.5 and Gorgonians, Ascidians and Molluscs were 15.5, 15.5 and 8.5 respectively numbers per 50 m2. Sponges was found in higher density .The overall abundance of fishes in Kudankulam area was fair. Most common fishes were Lethrinus sp., Lutjanus sp., Upeneus sp., Scarus sp., Chaetodon sp., Carangoides sp. and Odonus sp. Unexplored sea grass and assessment of associated flora and fauna will create regular monitoring function of this important study area. Since various developmental activities are emerging steadily in this region, and the nuclear power plant is also going to be operational in the near future, this study becomes important and provides baseline information. Hence, it exceedingly vital information on marine environment and biodiversity in order to assess for conservation and management measures

V. Ashok Prabu.pmd

Abstract Seasonal variations of physico-chemical parameters such as rainfall, temperature, salinity, pH, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate were studied from two different stations in Uppanar estuary, Cuddalore, southeast coast of India from April 2000 to March 2002. Atmospheric and surface water temperatures (°C) varied from 28 to 40.5 and 26 to 38 respectively. The salinity (‰), pH and dissolved oxygen (ml l -1 ) ranges were: 6.0-38.0; 7.1-8.2 and 2.4 to 4.5 respectively. Nutrient concentrations also varied considerably; nitrates: 8.15-25.66 µM, nitrites: 1.05-4.15 µM, phosphates: 0.17-2.96µM and reactive silicates: 27-168 µM. Nutrient concentrations were higher during monsoon season and low during summer

Community structure of microzooplankton in a tropical estuary (Uppanar) and a mangrove (Pichavaram) from the southeast coast of India

In the marine and estuarine waters of Cuddalore, the southeast coast of India microzooplankton have previously been sparingly investigated. Micro-zooplankton community structure (species composition, abundance, diversity, richness, evenness) of an estuary and mangroves of the Cuddalore and Pichavaram areas, southeast India were investigated in detail. Monthly samples were taken from April 2000 to March 2002, from four fixed stations. Micro-zooplankton taxon composition and abundance showed seasonal variations being highest in summer (45 to 50 ind./l in April to August 2000; 60 to 67.5 ind./l in April to June 2001) and lowest during the monsoon (6 to 16 ind./l in September to December 2000; 7 to 19 ind./l in October to December 2001). The total abundance of microzooplankton was in the range of 10.3-65.0 ind./l in Cuddalore areas (Stations 1 and 2) and 5.2 - 67.5 ind./l in Pichavaram mangroves (Stations 3 and 4). Over the study period, tintinnids dominated the microzooplankton community in terms of both abundance and species diversity. The remaining taxa included Radiolaria, Foraminifera, Rotifera, ciliates other than tintinnids, and metazoans. A total of 62 and 74 species of microzooplankton were recorded from Cuddalore and Pichavaram mangroves respectively. Canonical Correspondence Analysis (CCA) was applied to discriminate environmental factors associated with the microzooplankton community at the species level. The results of the study provide a basis for rational sustainable exploitation of Cuddalore waters and future research on its living resources. Furthermore, a comparison of results with studies from around the world showed a very strong, significant relationship between abundance and sampling methods underlining the need for standardized protocols