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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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Shanta Nair C. Mohandass P. A. Loka Bharathi G. Sheelu Raghukumar Chandralata 《Marine Georesources & Geotechnology》2000,18(3):273-283
The response of sediment bacteria and biochemical variables to benthic disturbance was investigated in the Central Indian Ocean Basin from cores at nine stations. Generally, bacterial density and biochemical variables declined vertically with depth in the upper layers of the cores. Mechanical disturbance caused by a hydraulic disturber brought about a substantial decrease in total bacterial numbers. However, the numbers of retrievable bacteria increased by two orders of magnitude. The biochemical parameters decreased in quantity with a shift in the linear relationship. The data suggest that abiotic artifacts will directly affect the biomass and biochemistry of the sediment. 相似文献
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Shanta Nair C. Mohandass P. A. Loka Bharathi G. Sheelu Raghukumar Chandralata 《Marine Georesources & Geotechnology》2013,31(3):273-283
Abstract The response of sediment bacteria and biochemical variables to benthic disturbance was investigated in the Central Indian Ocean Basin from cores at nine stations. Generally, bacterial density and biochemical variables declined vertically with depth in the upper layers of the cores. Mechanical disturbance caused by a hydraulic disturber brought about a substantial decrease in total bacterial numbers. However, the numbers of retrievable bacteria increased by two orders of magnitude. The biochemical parameters decreased in quantity with a shift in the linear relationship. The data suggest that abiotic artifacts will directly affect the biomass and biochemistry of the sediment. 相似文献
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Fungal Invasion of Massive Corals 总被引：2，自引：0，他引：2
Abstract. Five species of corals from the Andaman Islands in the Bay of Bengal (Indian Ocean) have been regularly found to have single or multiple necrotic patches. The occurrence of such corals with necrotic patches varied from 10–50% in the field. Sections revealed a septate dark brown mycelial fungus on the surface and subsurface of the dead patches in five coral species. The fungus was isolated in culture and identified as Scolecobasidium sp.
The fungus formed a distinct dense brown to black zone of 0.5-1.5 cm width immediately below the surface of the corals. In terms of biomass, the fungus was estimated to contribute 3–5 mg cm-3 of coral skeleton. 相似文献
The fungus formed a distinct dense brown to black zone of 0.5-1.5 cm width immediately below the surface of the corals. In terms of biomass, the fungus was estimated to contribute 3–5 mg cm
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S. Pavithran B. S. Ingole M. Nanajkar C. Raghukumar B. N. Nath A. B. Valsangkar 《Journal of Earth System Science》2009,118(6):689-700
The deep sea is well known for its high faunal diversity. But the current interest in its abundant polymetallic nodules, poses
a threat to the little known benthic organisms surviving in this unique environment. The present study is the first attempt
to document the Indian Ocean abyssal benthic diversity of macroinvertebrates and to investigate its relation to the surface
primary production (chl-a), sediment labile organic matter, organic carbon and texture. The present study is based on 87 individuals. Altogether 39
macroinvertebrate genera were obtained from water depths of 4500–5500 m from 23 box cores. Reduction in macrobenthic density
was seen towards the southern latitudes. The area was dominated by deposit feeding macrobenthos. Vertically, the fauna was
distributed down to 30 cm depth, with the highest faunal density in the top 2–5 cm sediment section. The values for population
density were strongly correlated with surface water chl-a and sediment protein, indicating supply of fresh organic matter as a critical factor for maintaining the deep sea benthic
diversity and abundance. 相似文献
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