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This paper presents a short review of some of the notable contributions by scientists from several parts of the world in furthering our understanding of the seafloor hydrothermal activity on the Indian Ocean ridges (IOR). Studies to date on the hydrothermal plumes and vents on the IOR and the marine sediments around the vents highlight the complex nature of hydrothermal activity on the Indian Ocean ridge system which is characterised by varying spreading rates, differences in the host rock system and perceptible variations in the chemical composition of the hydrothermal fluids. [ABSTRACT FROM AUTHOR]

Chromium (Cr) released from industrial units such as tanneries, textile and electroplating industries is detrimental to the surrounding ecosystems and human health. The focus of the present study was to check the Cr(VI) removal efficiency by marine-derived fungi from liquid broth. Amongst the three Cr(VI) tolerant isolates, #NIOSN-SK56-S19 (Aspergillus sydowii) showed Cr-removal efficiency of 0.01 mg Cr mg−1 biomass resulting in 26% abatement of total Cr with just 2.8 mg of biomass produced during the growth in 300 ppm Cr(VI). Scanning Electron Microscopy revealed aggregation of mycelial biomass with exopolysaccharide, while Electron Dispersive Spectroscopy showed the presence of Cr2O3 inside the biomass indicating presence of active Cr(VI) removal mechanisms. This was further supported when the Cr(VI) removal was monitored using DPC (1,5-diphenylcarbazide) method. The results of this study point to the potential of marine-derived fungal isolates for Cr(VI) removal. [ABSTRACT FROM AUTHOR]

Total Hg distributions and its speciation were determined in two sediment cores collected from the western continental marginal high of India. Total Hg content in the sediment was found to gradually increase (by approximately two times) towards the surface in both the cores. It was found that Hg was preferentially bound to sulfide under anoxic condition. However, redox-mediated reactions in the upper part of the core influenced the total Hg content in the sediment cores. This study suggests that probable increase in authigenic and allogenic Hg deposition attributed to the increasing Hg concentration in the surface sediment in the study area. [ABSTRACT FROM AUTHOR]