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Chakkaravarthy V.M.,National Coral Reef Research Institute | Vincent S.,Loyola Institute of Frontier Energy | Ambrose T.,Loyola Institute of Frontier Energy
Journal of Environmental Science and Technology | Year: 2011

The study aimed to provide detailed picture and baseline data about recent outbreak of chikungunya virus in public health sectors. The data were collected from the Director of Medical Science (DMS) department of economic and statistics in Chennai. The present investigation, chikungunya outbreak in different districts of Tamil Nadu was plotted in Geographic Information Systems (GIS) software and rainfall was correlated to forecast with recent outbreak. Smoothing methods was adapted to filter the data. Chikungunya outbreak was high at 8 districts; chikungunya fever cases were not recorded in 1 district, chikungunya prevalence was very low in 2 districts and in the rest of 19 districts, chikungunya fever cases were moderately recorded in Tamil Nadu. The re-emergence and epidemics are unpredictable phenomena but the impact of such events can be ameliorated by appropriate knowledge and by being in the right state of preparedness. © 2011 Asian Network for Scientific Information. Source


Chakkaravarthy V.M.,National Coral Reef Research Institute | Ambrose T.,Loyola Institute of Frontier Energy | Vincent S.,Loyola Institute of Frontier Energy | Arunachalam R.,Manonmaniam Sundaranar University | And 3 more authors.
Journal of Entomology | Year: 2011

The aim of the present investigation is to test the larvicidal activity of Azadirachta indica (A. Juss) and Datura metel (Linn.) leaf extract against the third instar larvae of C. quinquefasciatus (Say) (Diptera: Culicidae). A. indica and D. metel leaf extracted by hexane and chloroform extract method at various concentrations. The hexane extract of A. indica and D. metel at 62.5, 125, 250, 500 and 1000 ppm were showed 24, 36, 55, 64 and 72.50% mortality where second one shows 9, 17.50, 30, 42 and 57% mortality, respectively. The chloroform extract of A. indica was showed 12, 48.50, 56.50, 73 and 87% mortality where D. metel shows 13.75, 27, 32, 47 and 62% mortality respectively. The hexane and chloroform extract of A. indica and D. metel had significant larvicidal effect with LC50 values were 246.38, 198.82, 709.96 and 562.07 ppm respectively. At 24 h post-treatment against late third instar larvae, the chloroform extracts of A. indica and D. metel were found to be more effective than hexane extracts and caused a larval mortality of 87 and 62%, respectively at 1000 ppm concentration. The larvicidal effect of A. indica and D. metel against C. quinquefasciatus make these plant products are potential alternative to synthetic insecticide in mosquito control plans. © 2011 Academic Journals Inc. Source


Mondal T.,National Coral Reef Research Institute | Raghunathan C.,National Coral Reef Research Institute | Venkataraman K.,Zoological Survey of India
Indian Journal of Geo-Marine Sciences | Year: 2014

Andaman Sea is one of the highly productive seas in the world. The western boundary of the Andaman Sea is bordering Andaman and Nicobar Islands which harbours more than 400 species of scleractinian coral with the formation of fringing reef along the continental shelf. Sclearctinians corals and zooxanthallae (micro algae) are setting up a mutual symbiotic relationship for the survival of each other. A fundamental niche is very much required to maintain the above said relationship. Temperature is one of the curators to make the niche sense. Abrupt rise in Surface Sea Temperature (28°C to 31.7°C) was recorded in April to July 2010 which leads to massive coral bleaching i.e. displacement zooxanthallae from residing scleractinian to the mark of 80±10.5%. On resumption of normal environmental features in due course, recuperation of bleached corals or re-association of zooxanthallae with scleractinian corals was measured up to a maximum of 81.84±3.7% over the period of year. Besides new recruitment of corals (23.15±6.9%) was also noticed in reef areas of Andaman and Nicobar Islands. Coral bleaching is yet another clarion call for Andaman Sea on climate change which needs to be mitigated through effective managerial strategies at regional as well as global scale. © 2014, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved. Source


Mondal T.,National Coral Reef Research Institute | Raghunathan C.,National Coral Reef Research Institute | Venkataraman K.,Zoological Survey of India
Indian Journal of Geo-Marine Sciences | Year: 2014

Coral reefs of Andaman & Nicobar Islands are one of the best reefs in Indo-Pacific regions. These groups are attributed with fringing type of coral reefs with a 418 species distributed in a significant manner1. Coral reefs and their associated faunal as well as floral components have the greater capability to expedite the highest marine biodiversity in the world. More than 500 million people around the globe are fully dependent on these ecosystems for food, jobs, recreation, ethological values etc. These also have a tremendous ecological investment towards the protection of biodiversity as well as storm related damage and problems. Regrettably, degradation in this coral reef environment can be seen mainly due to human activities and sudden natural calamities or threats which used to arise from climatic changes. Changes in climatic features are now well known or established greatest threats to coral reefs worldwide towards destruction. Corals are very sensitive solitary or colonial organisms which inhabit in between specific range of temperature, salinity, turbidity, etc. Alteration in any of the factors manually or naturally, will show significant differentiations in the life cycle of the coral reefs. © 2014, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved. Source


Mondal T.,National Coral Reef Research Institute | Raghunathan C.,National Coral Reef Research Institute | Venkataraman K.,Zoological Survey of India
Indian Journal of Marine Sciences | Year: 2013

Fringing reefs of Andaman & Nicobar group of islands harbor 45 species of mushroom corals species up to the depth of 30 m. An individual of Cycloseris somervillei (Gardiner, 1909) was sampled from five study areas. Seven different morphological characters of each specimen of the target species were measured. Those characters were differed significantly among the specimens of study sites. Environmental parameter viz. temperature and rainfall was also measured to make a correlation between morphological differences and environmental factors. Depth plays a crucial role in the alteration of structural conformation. Underwater visibility also has an impact on the structural variation of the same species at different sites. This paper deals with the morphological variation of a species of mushroom coral i. e. Cycloseris somervillei in response to the environmental clues. Source

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