http://nopr.niscair.res.in/handle/123456789/1498 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/4172 Title: Evolution of Iskapalli lagoon in Penner delta region, east coast of India—A sedimentological and palynological approach <br/> <br/>Authors: Seetharamaia, J; Farooqui, Anjum; Suryabhagavan, K V; Rao, K Nageswara <br/> <br/>Abstract: The Holocene evolution of the Iskapalli lagoon has been reconstructed through landform mapping, vibracore lithology and foraminiferal analysis, supplemented by radiocarbon dating. The characteristics: texture, boundary surfaces and the palynological assemblages of the lagoon sediments obtained from two cores indicate three distinct sediment units. The lower part of the core (Unit I) consisting of highly (>85%) oxidized coarse sand mixed with shells, moderate bioturbation, high concentration of <i style="">Spiniferites, Casuarina</i>, fungal spores and algal cysts together with terrestrial herbaceous taxa and sub-parallel laminations suggests deposition in a sandy river mouth bar environment under strong wave influence. The middle part of the core (Unit II) comprising high silty to sandy mud, and parallel laminations together with <i style="">Protoperidinium</i> sp., <i style="">Rhizophora</i> and <i style="">Avicennia </i>indicated low energy lagoonal environment analogous to the modern lagoonal conditions. The upper part of the cores (Unit III) consisting of well sorted fine sands with abundant terrestrial taxa are considered to be wind blown sands. The oxidized condition of the distributary mouth bar sediments of Unit I and the occurrence of fine sediments of Unit II suggest the lagoon had witnessed at least one cycle of sea level fall and rise during the Late Holocene between 2000 yr BP and 1500 yr BP. <b style=""></b> <br/> <br/>Page(s): 267-273 http://nopr.niscair.res.in/handle/123456789/1567 Title: Isolation of antagonistic marine bacteria from the surface of the gorgonian corals at Tuticorin, south east coast of India <br/> <br/>Authors: Gnanambal, K. Mary Elizabeth; Chellaram, C.; Patterson, Jamila <br/> <br/>Abstract: Culturable heterotrophic bacteria present on the surface of two gorgonian corals, Subergorgia suberosa and Junceella juncea were isolated and the number of pigmented and non-pigmented strains was noted. The antagonistic effect of the marine isolates was tested against 8 human pathogens and 7 fish pathogens. It was observed that 82% (289) of the isolated bacterial strains were found to be non-pigmented and 61% (214) were identified as Gram-negative. Only 13% (46) of the isolated bacteria were found to be antagonistic against both human and fish pathogens. 74% (34) of the producer strains were found to be non-pigmented, however, mild antagonistic activity was found to be exhibited also by the pigmented strains. Percentage of Gram-negative strains showing activity was found to be 68% (145). All the indicator strains tested were inhibited by at least 10 of the antagonistic marine bacteria. A higher degree of inhibition was conferred by 3 of the isolates (G₁₁₀, G₁₁₁ and G₁₁₃) with maximum zones of inhibition against Escherichia coli (5.5mm) by the strain G₁₁₃. The strains showing higher degree of inhibition against human pathogens (G₁₁₀, G₁₁₁ and G₁₁₃) showed potent inhibition against the fish pathogens too with maximum inhibition against Proteus mirabilis (5mm) by the strain G₁₁₀. The symbiotic bacteria present on the surfaces of these gorgonian corals may yield novel metabolites. <br/> <br/>Page(s): 316-319 http://nopr.niscair.res.in/handle/123456789/1566 Title: Mangrove mapping and change detection around Mumbai (Bombay) using remotely sensed data <br/> <br/>Authors: Vijay, V.; Biradar, R. S.; Inamdar, A. B.; Deshmukhe, G.; Baji, S.; Pikle, Madhavi <br/> <br/>Abstract: Remote sensing technology was used to detect changes in the mangrove habitat around the Mumbai suburban region. For this purpose, cloud free satellite images on the scale of 1 : 50,000 from Indian Remote Sensing (IRS) satellite IRS-ID and IRS-IC were used. The total area of mangroves in Mumbai suburban region has been estimated to be 56.40 km² (including mud flats) with dense mangroves contributing 45.4% to the total. During 1990 to 2001, a total mangrove area of 36.54 km² was lost, indicating a 39.32% decrease in the area of mangroves. It has been observed that the quantitative degradation of mangrove vegetation is largely due to burgeoning population pressure, construction and development activities, conversion to agricultural land and fish farms besides the effect of industrial effluents. Avicennia marina was found to be the most dominant mangrove species. Measures have been suggested for conservation and management of mangroves of Mumbai on a sustainable basis. <br/> <br/>Page(s): 310-315 http://nopr.niscair.res.in/handle/123456789/1565 Title: Subareal wave pressures, layer thicknesses, run-up and run-down velocity on sea walls <br/> <br/>Authors: Neelamani, S <br/> <br/>Abstract: Wave pressures, layer thickness, run-up and run-down velocities were measured on the splash/subareal zone (the part of the seawall which is partially in water during run up and partially in the air during run down) of plane seawalls for a wide range of hydrodynamic parameters and seawall slopes. The complete wave breaking range (spilling, plunging, collapsing and surging) is covered in the study. The maximum wave pressure in the subareal region can be as high as 1.2 times the static pressure due to water column equal to the incident wave height. The maximum wave pressure at any point is higher than the water pressure induced by the layer thickness due to the dynamic contribution of the flowing water on the seawall. The maximum run up and run down velocity can be as high as 25 times the maximum horizontal water particle velocity in deep water. The run-down velocity is found to be higher than the run-up velocity for the same input condition. Using the measured data, empirical formulae are proposed to predict the subareal wave pressures, layer thicknesses, and run-up and run-down velocities. The proposed formulae incorporate the surf similarity parameter and relative elevation of the location on the subareal region of the seawall. The empirical equations are simple, reliable and hence can be used for the optimal design of plane seawalls. <br/> <br/>Page(s): 299-309