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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Carbon mineralization pathways and bioturbation in coastal Brazilian sediments

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Quintana, Cintia O. [1, 2] ; Shimabukuro, Maurcio [1] ; Pereira, Camila O. [1] ; Alves, Betina G. R. [1] ; Moraes, Paula C. [1] ; Valdemarsen, Thomas [2] ; Kristensen, Erik [2] ; Sumida, Paulo Y. G. [1]
Total Authors: 8
[1] Univ Sao Paulo, Inst Oceanog, BR-05508120 Sao Paulo - Brazil
[2] Univ Southern Denmark, Dept Biol, DK-5230 Odense M - Denmark
Total Affiliations: 2
Document type: Journal article
Source: SCIENTIFIC REPORTS; v. 5, NOV 3 2015.
Web of Science Citations: 11

Carbon mineralization processes and their dependence on environmental conditions (e.g. through macrobenthic bioturbation) have been widely studied in temperate coastal sediments, but almost nothing is known about these processes in subtropical coastal sediments. This study investigated pathways of organic carbon mineralization and associated effects of macrobenthic bioturbation in winter and summer (September 2012 and February 2014) at the SE Brazilian coast. Iron reduction (FeR) was responsible for 73-81% of total microbial carbon mineralization in September 2012 and 3261% in February 2014. Similar high rates of FeR have only been documented a few times in coastal sediments and can be sustained by the presence of large bioturbators. Denitrification accounted for 5-27% of total microbial carbon mineralization while no SO42- reduction was detected in any season. Redox profiles suggested that conditions were less reduced in February 2014 than in September 2012, probably associated with low reactivity of the organic matter, higher rates of aerobic respiration and bioirrigation by the higher density of small-macrofauna. Bioturbation by small macrofauna may maintain the sediment oxidized in summer, while large-sized species stimulate the reoxidation of reduced compounds throughout the year. Therefore, bioturbation seems to have an important role modulating the pathways of carbon mineralization in the area. (AU)

FAPESP's process: 12/06121-1 - Pathways of organic matter degradation in marine coastal sediments: implications to ecosystem functioning
Grantee:Cintia Organo Quintana
Support type: Scholarships in Brazil - Post-Doctorate