Record Details

Ambient iron concentration regulates the sulfate reducing activity in the mangrove swamps of Diwar, Goa, India

DRS at CSIR-National Institute of Oceanography

View Archive Info
 
 
Field Value
 
Title Ambient iron concentration regulates the sulfate reducing activity in the mangrove swamps of Diwar, Goa, India
 
Creator Attria, K.
Kerkar,S.
LokaBharathi, P.A.
 
Subject mangrove swamps
sulphate reduction
organic matter
 
Description In order to test the hypothesis that the ambient iron concentrations could regulate sulfate reducing activity (SRA) in mangrove areas, 10 cm cores were examined from test and reference sites. The test site at Diwar mangrove ecosystem is highly influenced by iron released by the movement of barges carrying iron ore during the non-monsoon seasons and the reference site at Tuvem is relatively pristine. The average iron concentrations were 17.9% (+ or -8.06) at Diwar and 6.3% (+ or -1.5) at Tuvem. Sulfate reducing rates (SRR) ranged from 50.21 to 698.66 nM cm sup(3) d sup(1) at Tuvem, and from 23.32 to 294.49 nM cm sup(3) d sup(1) in Diwar. Pearson?s correlation coefficients between SRR and environmental parameters showed that at Tuvem, the SRR was controlled by SO sub(4) sup(-2) (r = 0.498, p < 0.001, n = 60) more than organic carbon (r = 0.316 p < 0.05, n = 60). At Diwar, the SRR was governed by the iron concentrations at an r-value of -0.761 (p < 0.001, n = 60), suggesting that ca.58% of the variation in SRR was influenced negatively by variations in ambient iron concentrations. This influence was more than the positive influence of TOC (r = 0.615, p < 0.001, n =60). Laboratory experiments to check the influence of iron on SRR also supported our field observations. At an experimental manipulation of 50 ppm Fe sup(3+) there was an increase in SRR but at 100 ppm an inhibitory effect was observed. At 1000 ppm Fe sup(3+) there was a decrease in the SRR up to 93% of the control. Thus, our study showed that ambient iron concentrations influence SRR negatively at Diwar and counters the positive influence of organic carbon. Consequently, the influence could cascade to other biogeochemical processes in these mangrove swamps, especially the mineralization of organic matter to carbon dioxide by sulfate respiration.
 
Date 2011-11-11T12:50:02Z
2011-11-11T12:50:02Z
2011
 
Type Journal Article
 
Identifier Estuarine, Coastal and Shelf Science,vol.95; 2011; 156-164
http://drs.nio.org/drs/handle/2264/3948
 
Language en
 
Rights An edited version of this paper was published by Elsevier. Copyright [2011] Elsevier
 
Publisher Elsevier