Fattening of mud crab: an approach of aquasilviculture in Andaman Islands

During September - December 2004, mud crab fattening was attempted in tide-fed earthen ponds in Lakshmipur (North Andaman) and Bamboo Tickri (Middle Andaman) with mangroves such as Rhizophora mucronata, R. apiculata and Avicennia marina, covering 60 to 80% of the total pond area. Water crabs of Scylla tranquebarica, S. olivacea and S. serrata, each weighing 500 - 1500 g were stocked in the pond at a density of 0.5 kg/m2 with suitable hideouts to reduce cannibalism. In 30 to 35 days, 85% survival was obtained with 8% weight increment. This paper outlines the measures that may be adopted for practicing aquaculture in mangroves

Assessment of post tsunami coral reef resource in Pongi Balu coast, south Andaman Islands

In the present study, an assessment of the status of coral reefs along the Pongi Balu coast, south Andaman Islands, which is a part of the Mahatma Gandhi Marine National Park, has been made by scuba diving, low draft glass-bottom boat and visual interpretation in some places during low-tide condition. The coral reef boundaries have been accurately determined with the help of a low draft glass-bottom boat fitted with a real time kinematics global positioning system, and the existing coral reefs map of the area has been updated using the geographic information system technique. A total of 161.6 ha of previously existed live coral reefs were surveyed along the Pongi Balu coast and out of that ‘live coral’ was found over 81.4 ha and ‘dead coral’ was found over 60.6 ha whereas 19.6 ha area was found to have been lost from the existing coral reefs and categorized as ‘no coral’. The study highlights a few natural and anthropogenic factors affecting the existing coral reefs and hindering the re-establishment of coral reefs in the study area

Prevention of Acyl homoserine lactone (AHL) mediated biofilm formation by selected flora of Andaman & Nicobar Islands

2101-2106Acyl homoserine lactones (AHL) are inter-cellular signal molecules and it controls the population density dependent growth behavior of bacteria in a biofilm. The AHL mediated biofilm formation and its inhibition was evaluated using methanol (MeOH), ethyl acetate (EtOAc), n-butanol (n-BuOH) and aqueous (H2O) fractions of 12 marine flora of Andaman and Nicobar Islands with fouling Vibrio sp., isolated from root surface of mangrove. <span style="color:black;mso-font-kerning:12.0pt;mso-bidi-font-weight: bold;mso-bidi-font-style:italic">The 12 fractions were assayed for inhibition of AHL promoted biofilm formation of Vibrio sp. and the results showed that seven fractions possess AHL inhibitory potential. The extracts of mangroves <span style="color:black;mso-font-kerning:12.0pt;mso-bidi-font-weight: bold">Avicennia marina<span style="color:black;mso-font-kerning: 12.0pt;mso-bidi-font-weight:bold;mso-bidi-font-style:italic">, Rhizophora mucronata and macroalgae <span style="color:black;mso-font-kerning:12.0pt;mso-bidi-font-weight: bold">Sargassum ilicifolium, Actinotrichia fragilis<span style="color:black;mso-font-kerning:12.0pt;mso-bidi-font-weight:bold; mso-bidi-font-style:italic">, Amphiroa anceps and Padina tetrastromatica had anti-biofilm activity at least in one of the four solvent fractions. Out of these, EtOAc<span style="color:black;mso-font-kerning:12.0pt; mso-bidi-font-weight:bold;mso-bidi-font-style:italic"> fraction of Padina tetrastromatica (60% inhibition at 50 µg) showed higher inhibition on AHL mediated antibiofilm activity. The concentration dependent (10 - 200 µg) study of this fraction showed that there was a significant reduction in biofilm formation by increase in concentration with an IC50 (50 % inhibitory concentration) of 4<span style="color:black;mso-font-kerning:12.0pt;mso-bidi-font-weight:bold; mso-bidi-font-style:italic">0 µg. Thus it was concluded that the AHL mediated biofilm inhibitory compound from Padina tetrastromatica can be used for the development of anti-quorum sensing antifoulants. </span

<span style="font-size:15.0pt;line-height: 115%;font-family:"Times New Roman";mso-fareast-font-family:Calibri;mso-bidi-font-family: "Times New Roman";mso-ansi-language:EN-US;mso-fareast-language:EN-US; mso-bidi-language:AR-SA" lang="EN-US">Dominance of <i style="mso-bidi-font-style:normal">Trichodesmium</i> and associated biological and physico-chemical parameters in coastal water of Port Blair, South Andaman Island</span>

1739-1745<span style="font-size:9.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:calibri;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">Dominance of the cyanobacteria <i style="mso-bidi-font-style: normal">Trichodesmium was observed in the plankton samples collected from the coastal water of Port Blair during May, 2011. No discernible change in the colour of the surface water was observed. However the cumulative samples collected using plankton net were red in colour. The number of Trichodesmium filaments and colonies were found increasing towards the open sea region. Two species of cyanobacteria viz. Trichodesmium thiebautii and Trichodesmium erythraeum were identified. The number of filaments of T. thiebautii were 10 to 15 times more than that of <i style="mso-bidi-font-style: normal">T. erythraeum. The inorganic phosphate and ammonia concentrations were higher during the time of <i style="mso-bidi-font-style: normal">Trichodesmium dominance. The diatom <i style="mso-bidi-font-style: normal">Navicula membranaceae was the second dominating species followed by Nitzschia seriata, N. closterium and Leptocylindrus danicus. In case of zooplankton, the harpacticoid copepods such as Macrosetella spp., Microsetella spp. and cyclopoid copepods like <i style="mso-bidi-font-style: normal">Copilia spp., Sapphirina spp. were found abundant. Reason for the Trichodesmium dominance in the nearshore water of Port Blair could be due to its stable coastal water conditions during summer. </span

Not Available

Not AvailableIn the present study, an assessment of the status of coral reefs along the Pongi Balu coast, south Andaman Islands, which is a part of the Mahatma Gandhi Marine National Park, has been made by scuba diving, low draft glass-bottom boat and visual interpretation in some places during low-tide condition. The coral reef boundaries have been accurately determined with the help of a low draft glass-bottom boat fitted with a real time kinematics global positioning system, and the existing coral reefs map of the area has been updated using the geographic information system technique. A total of 161.6 ha of previously existed live coral reefs were surveyed along the Pongi Balu coast and out of that ‘live coral’ was found over 81.4 ha and ‘dead coral’ was found over 60.6 ha whereas 19.6 ha area was found to have been lost from the existing coral reefs and categorized as ‘no coral’. The study highlights a few natural and anthropogenic factors affecting the existing coral reefs and hindering the re-establishment of coral reefs in the study area.Not Availabl

Keith Brander

Abstract The microbial diversity in the intestine of laboratory reared and wild spiny lobster Panulirus versicolor (Latreille, 1804) from Andaman Island was evaluated. In the wild lobsters, Enterobactericeae was 67%, whereas in the laboratory grown lobsters Vibrionaceae family was dominant (71%). The hyper-enzyme producing proteolytic bacterial species ranged from 21 to 25 × 10 6 CFU ml -1 in the foregut of lab reared lobsters compared to 13-18 ×10 2 CFU ml -1 in wild lobsters. The hyper-enzyme producing cellulolytic bacteria, antimicrobial synthesizing bacteria and fungi were dominant in the wild P. versicolor. The hyper-enzyme producing bacteria and antimicrobial synthesizing bacteria would be valuable for the production of artificial feed for the laboratory reared aquatic animals

Long-lived atmospheric trace gases measurements in flask samples from three stations in India

International audienceWith the rapid growth in population and economic development, emissions of greenhouse gases (GHGs) from the Indian subcontinent have sharply increased during recent decades. However, evaluation of regional fluxes of GHGs and characterization of their spatial and temporal variations by atmospheric inversions remain uncertain due to a sparse regional atmospheric observation network. As a result of an Indo-French collaboration, three new atmospheric stations were established in India at Hanle (HLE), Pondicherry (PON) and Port Blair (PBL), with the objective of monitoring the atmospheric concentrations of GHGs and other trace gases. Here we present the results of the measurements of CO 2 , CH 4 , N 2 O, SF 6 , CO, and H 2 from regular flask sampling at these three stations over the period 2007-2011. For each species, annual means, seasonal cycles and gradients between stations were calculated and related to variations in natural GHG fluxes, anthropogenic emissions, and monsoon circulations. Covariances between species at the synoptic scale were analyzed to investigate the likely source(s) of emissions. The flask measurements of various trace gases at the three stations have the potential to constrain the inversions of fluxes over southern and northeastern India. However , this network of ground stations needs further extension to other parts of India to better constrain the GHG budgets at regional and continental scales