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Distribution and sources of organic matter in surface sediments of the eastern continental margin of India

IR@NIO: CSIR-National Institute Of Oceanography, Goa

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Creator Krishna, M.S.
Naidu, S.A.
Subbaiah, Ch.V.
Sarma, V.V.S.S.
Reddy, N.P.C.
 
Date 2014-09-19T09:56:03Z
2014-09-19T09:56:03Z
2013
 
Identifier Journal Of Geophysical Research: Biogeosciences, vol.118(4); 2013; 1484-1494
http://drs.nio.org/drs/handle/2264/4602
 
Description The sources and distribution of organic matter (OM) in surface sediments of the eastern continental margin of India, including the region influenced by river discharge, were investigated using content, molar C:N ratios and stable isotopes of carbon and nitrogen. Despite relatively high water column integrated chlorophyll-a concentrations were found in the continental shelf than the slope; however, the lower sediment organic carbon (SOC) was found in the former than the latter region suggesting that in situ production did not play significant role on preservation of SOC in the coastal Bay of Bengal. The broad range of delta<sup>13</sup>C of SOC (-23.2 to -16.7‰) suggests that OM is a broad mixture of terrestrial and marine OM. Relative contributions from terrestrial C3 and C4 plants and marine sources are quantified as 34%, 23%, and 43%, respectively, indicating that dominant source of allochthonous OM (~57%) in the coastal Bay of Bengal. Relatively higher contribution of OM from C4 plants was found in the sediments at off river Krishna indicating that this region received detritus of agricultural crops such as jowar, bajra, and sugar cane, which are dominant in its drainage basin, during SW monsoon. This study revealed that relatively high OM preserved in the slope than shelf region along the coastal Bay of Bengal and the composition of OM is primarily controlled by the type of agricultural crops and vegetation in the drainage basin of the river
 
Language en
 
Publisher American Geophysical Union
 
Rights An edited version of this paper was published by AGU. Copyright [2013] AGU. To view the published open abstract, go to http://dx.doi.org/10.1002/2013JG002424
 
Subject organic matter
river discharge
carbon
nitrogen isotopes
sediments
agriculture
continental margins
continental slope
 
Title Distribution and sources of organic matter in surface sediments of the eastern continental margin of India
 
Type Journal Article