Monitoring the sedimentary carbon in an artificially disturbed deep-sea sedimentary environment

Show simple item record Nath, B.N. Khadge, N.H. Nabar, S. Raghukumar, C. Ingole, B.S. Valsangkar, A.B. Sharma, R. Srinivas, K. 2012-05-09T10:45:34Z 2012-05-09T10:45:34Z 2012
dc.identifier.citation Environmental Monitoring and Assessment, vol.184; 2012; 2829-2844
dc.identifier.other no
dc.description.abstract An area of 0.6 km sup(2) in the manganese nodule field of the Central Indian Basin was physically disturbed and sediments discharged in the near bottom waters to simulate seabed mining and study its impact on benthic ecosystem. An estimated 2 to 3 tonnes of sedimentary organic carbon (C sub(org)) was resuspended into the water column during a 9-day experiment. The majority of the sediment cores from within the disturbed area and areas towards the south showed a approx. 30% increase in C sub(org) content as well as an increase in carbon burial rates after disturbance, though with a reduction in carbon/phosphorus ratios.High specific surface area (SSA approx. 25 m sup(2) g sup(-1)) and low C sub(org)/SSA ratios (mostly less than 0.5) are typical of deep-sea sediments. The increased C sub(org)values were probably due to the organic matter from dead biota and the migration and redeposition of fine-grained, organic-rich particles. Spatial distribution patterns of C sub(org) contents of cores taken before and after disturbance were used to infer the direction of plume migration and re-sedimentation. A positive relationship was observed between total and labile C sub(org) and macrobenthos density and total bacterial numbers prior to disturbance, whereas a negative relationship was seen after disturbance owing to drastic reduction in the density of macrofauna and bacteria. Overall decrease in labile organic matter, benthic biota and redistribution of organic matter suggest that the commercial mining of manganese nodules may have a significant immediate negative effect on the benthic ecosystem inducing changes in benthic community structure.
dc.language.iso en
dc.publisher Springer
dc.relation.requires Environ_Monit_Assess_184_2829.jpg
dc.rights An edited version of this paper was published by Springer. This paper is for R & D purpose and Copyright [2012] Springer.
dc.subject sediments
dc.subject ecosystem disturbance
dc.subject organic carbon
dc.subject environmental monitoring
dc.title Monitoring the sedimentary carbon in an artificially disturbed deep-sea sedimentary environment
dc.type Journal Article

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