Sources and implications of particulate organic matter from a small tropical river—Zuari River, India

Dearlyn Fernandes; Ying Wu; Prabhaker Vasant Shirodkar; Umesh Kumar Pradhan; Jing Zhang

doi:10.1007/s13131-020-1544-x

Volume 39 Issue 4

Apr. 2020

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Dearlyn Fernandes, Ying Wu, Prabhaker Vasant Shirodkar, Umesh Kumar Pradhan, Jing Zhang. Sources and implications of particulate organic matter from a small tropical river—Zuari River, India[J]. Acta Oceanologica Sinica, 2020, 39(4): 18-32. doi: 10.1007/s13131-020-1544-x

Citation:

Dearlyn Fernandes, Ying Wu, Prabhaker Vasant Shirodkar, Umesh Kumar Pradhan, Jing Zhang. Sources and implications of particulate organic matter from a small tropical river—Zuari River, India[J]. Acta Oceanologica Sinica, 2020, 39(4): 18-32. doi: 10.1007/s13131-020-1544-x

Citation:

Dearlyn Fernandes, Ying Wu, Prabhaker Vasant Shirodkar, Umesh Kumar Pradhan, Jing Zhang. Sources and implications of particulate organic matter from a small tropical river—Zuari River, India[J]. Acta Oceanologica Sinica, 2020, 39(4): 18-32. doi: 10.1007/s13131-020-1544-x

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Sources and implications of particulate organic matter from a small tropical river—Zuari River, India

doi: 10.1007/s13131-020-1544-x

1.
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
2.
National Institute of Oceanography (Council of Scientific and Industrial Research), Dona Paula, Goa 403004, India
3.
National Institute of Oceanography (Council of Scientific and Industrial Research), Regional Centre, 4 Bungalows, Andheri (West) 400053, Mumbai, India

Funds: The National Natural Science Foundation of China under contract No. 41530960.

More Information

Corresponding author: E-mail: dearlynfernandes@qq.com
Received Date: 2019-07-01
Accepted Date: 2019-10-10

Available Online: 2020-12-28

Publish Date: 2020-04-25

Abstract

Abstract

Transitional ecosystems, estuaries and the coastal seas, are distinctively affected by natural and anthropogenic factors. Organic matter (OM) originating from terrestrial sources is exported by rivers and forms a key component of the global biogeochemical cycles. Most previous studies focused on the bulk biochemical and anthropogenic aspects affecting these ecosystems. In the present study, we examined the sources and fate of OM entrained within suspended particulate matter (SPM) of the Zuari River and its estuary, west coast of India. Besides using amino acid (AA) enantiomers (L- and D-forms) as biomarkers, other bulk biochemical parameters viz. particulate organic carbon (POC), δ¹³C, particulate nitrogen (PN), δ¹⁵N and chlorophyll a were analyzed. Surprisingly no significant temporal variations were observed in the parameters analyzed; nonetheless, salinity, POC, δ¹³C, PN, δ¹⁵N, glutamic acid, serine, alanine, tyrosine, leucine and D-aspartic acid exhibited significant spatial variability suggesting source differentiation. The POC content displayed weak temporal variability with low values observed during the post-monsoon season attributed to inputs from mixed sources. Estuarine samples were less depleted than the riverine samples suggesting contributions from marine plankton in addition to contributions from river plankton and terrestrial C₃ plants detritus. Labile OM was observed during the monsoon and post-monsoon seasons in the estuarine region. More degraded OM was noticed during the pre-monsoon season. Principal component analysis was used to ascertain the sources and factors influencing OM. Principally five factors were extracted explaining 84.52% of the total variance. The first component accounted for 27.10% of the variance suggesting the dominance of tidal influence whereas, the second component accounted for heterotrophic bacteria and their remnants associated with the particulate matter, contributing primarily to the AA pool. Based on this study we ascertained the role of the estuarine turbidity maximum (ETM) controlling the sources of POM and its implications to small tropical rivers. Thus, changes in temporal and regional settings are more likely to affect the natural biogeochemical cycles of small tropical rivers.
- Zuari River,
- estuarine turbidity maximum (ETM),
- suspended particulate matter (SPM),
- organic matter (OM),
- amino acids (AA),
- degradation index (DI)

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References(80)

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