Transport of Dissolved Organic Carbon, Nutrients, and Trace Metals from the Wilson and Blossom Rivers to Smeaton Bay, Southeast Alaska

1984 ◽  
Vol 41 (1) ◽  
pp. 180-190 ◽  
Author(s):  
Susan F. Sugai ◽  
David C. Burrell
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Large Scale ◽  
Nutrient Export ◽  
Drainage Basins ◽  
Southeast Alaska ◽  
Scale Removal ◽  
Reducing Conditions ◽  
Fe And Mn ◽  
Topographical Relief

Regional and seasonal differences in chemical input from the Wilson and Blossom rivers, two pristine, major salmon-producing rivers in southeast Alaska, were examined. For a period of 2 yr, concentrations of dissolved organic carbon, nutrients, Cu, Fe, and Mn in the rivers were determined at approximately monthly intervals and used to calculate export rates. Because of extremely high annual precipitation (400–450 cm) and drainage basins restricted by high topographical relief, the concentrations and export rates of nutrients and Cu are low in the rivers for most of the year. The maximum nutrient export from the Wilson–Blossom system appears to be closely tied to the annual salmon cycle. Iron and Mn export rates from the watersheds are much higher than those for Cu, reflecting solubilization of Fe and Mn under reducing conditions that develop in muskeg ponds during drought periods. The association of metals with organics allows transport of Fe and possibly other metals throughout the fjord system, in contrast with the large-scale removal of metals in or near the river's mouth, as has been observed elsewhere.

Spatial Variation in the Origin of Dissolved Organic Carbon in Snow on the Juneau Icefield, Southeast Alaska

2015 ◽  
Vol 49 (19) ◽  
pp. 11492-11499 ◽  
Author(s):  
Jason B. Fellman ◽  
Eran Hood ◽  
Peter A. Raymond ◽  
Aron Stubbins ◽  
Robert G.M. Spencer
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Spatial Variation ◽  
Southeast Alaska

scholarly journals Dissolved Organic Carbon Loading Stimulates Sediment Phosphorus Mobilization and Release: Preliminary Evidence From Xiangshan Port, East China Sea

2022 ◽  
Vol 9 ◽  
Author(s):  
Xu-Meng Dong ◽  
Shuo-Nan Ma ◽  
Hai-Jun Wang ◽  
Yuan-Yuan Li ◽  
Yan Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Large Scale ◽  
Preliminary Evidence ◽  
Tight Coupling ◽  
Overlying Water ◽  
P Release ◽  
Large Scale Field ◽  
P Mobilization ◽  
Labile P

Increasing concentrations of dissolved organic carbon (DOC) have been observed in coastal ecosystems worldwide over the past decade, and tight coupling of the carbon (C) and phosphorus (P) biogeochemical cycle has been recognized in aquatic ecosystems. However, there is still no consensus regarding the potential effects of DOC loading on sediment P release. In a 2-month mesocosm experiment, we tested the effects of DOC enrichment on sediment P release in six glass aquariums. Two treatments were set: Control (without sodium acetate (Na(CH3COO)) addition) and Na(CH3COO) addition (equivalent to 5 mg C L−1). The results showed the following: 1) DOC loading stimulated sediment P mobilization and release, as indicated by increases in the labile P recorded for 7-cm-deep sediment using diffusive gradients in thin films, the flux of P across the sediment–water interface, and the total P concentrations in the overlying water; and 2) stimulated alkaline phosphatase activity, increased P-solubilizing bacteria proportion, and decreased dissolved oxygen concentration were likely the primary mechanisms behind the DOC-stimulated sediment P mobilization and release. These results provide insight into the promotion of sediment P release induced by C addition. Further studies investigating the quantitative relationships between DOC loadings and P release are needed to fully elucidate the coupled roles of C and P, especially those based on large-scale field investigations with broader C forms and loadings.

scholarly journals The Influence of Dissolved Organic Carbon on the Microbial Community Associated with Tetraselmis striata for Bio-Diesel Production

2020 ◽  
Vol 10 (10) ◽  
pp. 3601
Author(s):  
Sae-Hee Kim ◽  
Jin Ho Kim ◽  
Seung Ho Baek ◽  
Joo-Hwan Kim ◽  
Penelope A. Ajani ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Large Scale ◽  
Food Web Structure ◽  
Bacterial Composition ◽  
Suitable Candidate ◽  
Web Structure ◽  
Tetraselmis Striata ◽  
And Function ◽  
Diesel Production

The green alga Tetraselmis striata is regarded as a suitable candidate microalga for bio-diesel production. Recently, T. striata was cultured near Yeonghueung Island, Korea, in a “marine culturing field”; however, its environmental impacts are not yet studied. We estimated the amount of dissolved organic carbon (DOC) released from T. striata cultivation in the marine culturing field, and we investigated the changes in bacterial composition. Then, we designed and installed a mesocosm for further understanding. From the mesocosm results, the DOC released from the cultivation of T. striata led to changes in bacterial communities, disturbance of the microbial food web structure, rapid depletion of nutrients, and a decrease in dissolved oxygen (DO) and pH. Our novel work demonstrates that large amounts of DOC secreted by large-scale microalgal cultures such as that of T. striata can potentially have a significant impact on the structure and function of the surrounding microbial ecosystem.

scholarly journals Rivers across the Siberian Arctic unearth the patterns of carbon release from thawing permafrost

2019 ◽  
Vol 116 (21) ◽  
pp. 10280-10285 ◽  
Author(s):  
Birgit Wild ◽  
August Andersson ◽  
Lisa Bröder ◽  
Jorien Vonk ◽  
Gustaf Hugelius ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Large Scale ◽  
Temporal Dynamics ◽  
High Temporal Resolution ◽  
Drainage Basins ◽  
Discontinuous Permafrost ◽  
Spatial And Temporal Dynamics ◽  
Siberian Arctic ◽  
Carbon Release ◽  
Thawing Permafrost

Climate warming is expected to mobilize northern permafrost and peat organic carbon (PP-C), yet magnitudes and system specifics of even current releases are poorly constrained. While part of the PP-C will degrade at point of thaw to CO2 and CH4 to directly amplify global warming, another part will enter the fluvial network, potentially providing a window to observe large-scale PP-C remobilization patterns. Here, we employ a decade-long, high-temporal resolution record of 14C in dissolved and particulate organic carbon (DOC and POC, respectively) to deconvolute PP-C release in the large drainage basins of rivers across Siberia: Ob, Yenisey, Lena, and Kolyma. The 14C-constrained estimate of export specifically from PP-C corresponds to only 17 ± 8% of total fluvial organic carbon and serves as a benchmark for monitoring changes to fluvial PP-C remobilization in a warming Arctic. Whereas DOC was dominated by recent organic carbon and poorly traced PP-C (12 ± 8%), POC carried a much stronger signature of PP-C (63 ± 10%) and represents the best window to detect spatial and temporal dynamics of PP-C release. Distinct seasonal patterns suggest that while DOC primarily stems from gradual leaching of surface soils, POC reflects abrupt collapse of deeper deposits. Higher dissolved PP-C export by Ob and Yenisey aligns with discontinuous permafrost that facilitates leaching, whereas higher particulate PP-C export by Lena and Kolyma likely echoes the thermokarst-induced collapse of Pleistocene deposits. Quantitative 14C-based fingerprinting of fluvial organic carbon thus provides an opportunity to elucidate large-scale dynamics of PP-C remobilization in response to Arctic warming.

scholarly journals Partial coupling and differential regulation of biologically and photochemically labile dissolved organic carbon across boreal aquatic networks

2014 ◽  
Vol 11 (20) ◽  
pp. 5969-5985 ◽  
Author(s):  
J.-F. Lapierre ◽  
P. A. del Giorgio
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Large Scale ◽  
Natural Waters ◽  
Boreal Lakes ◽  
Aquatic Environments ◽  
Photochemical Degradation ◽  
Landscape Gradients ◽  
Partial Coupling ◽  
Internal Production

Abstract. Despite the rapidly increasing volume of research on the biological and photochemical degradation of DOC (dissolved organic carbon) in aquatic environments, little is known of the large-scale patterns in biologically and photochemically degradable DOC (BDOC and PDOC, respectively) in continental watersheds, and on the links that exist between these two key properties that greatly influence the flow of carbon from continents to oceans. Here we explored the patterns in the concentrations and proportions of BDOC and PDOC across hundreds of boreal lakes, rivers and wetlands spanning a large range of system trophic status and terrestrial influence, and compared the drivers of these two reactive pools of DOC at the landscape level. Using standardized incubations of natural waters, we found that the concentrations of BDOC and PDOC covaried across all systems studied but were nevertheless related to different pools of dissolved organic matter (DOM; identified by fluorescence analyses) in ambient waters. Concentrations of nutrients and protein-like fluorescent DOM (FDOM) explained nearly half of the variation in BDOC, whereas PDOC was exclusively predicted by DOM optical properties, consistent with the photochemical degradability of specific FDOM pools that we experimentally determined. The concentrations of colored DOM (CDOM), which we use here as a proxy of terrestrial influence, almost entirely accounted for the observed relationship between FDOM and the concentrations of both BDOC and PDOC. The concentrations of CDOM and of the putative biolabile fluorescence component shifted from complete decoupling in clear-water environments to strong coupling in darker streams and wetlands. This suggests a baseline autochthonous BDOC pool fueled by internal production that is gradually overwhelmed by land-derived BDOC as terrestrial influence increases across landscape gradients. The importance of land as a major source of both biologically and photochemically degradable DOC for continental watersheds resulted in a partial coupling of those carbon pools in natural freshwaters, despite fundamental contrasts in terms of their composition and regulation.

CHARACTERISATION OF DISSOLVED ORGANIC CARBON (DOC) LEACHED FROM LEAVES IN WATER

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Markus Heryanto Langsa
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Organic Carbon ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Pyrolysis Gas Chromatography ◽  
Chromatography Mass Spectrometry ◽  
Pinus Radiate

<p>Penelitian ini bertujuan untuk menentukan senyawa organik khususnya organic karbon terlarut (DOC) dari dua spesies daun tumbuhan (<em>wandoo eucalyptus </em>and <em>pinus radiate, conifer</em>) yang larut dalam air selama periode 5 bulan leaching eksperimen. Kecepatan melarutnya senyawa organic ditentukan secara kuantitatif dan kualitatif menggunakan kombinasi dari beberapa teknik diantaranya Total Organic Carbon (TOC) analyser, Ultraviolet-Visible (UV-VIS) spektrokopi dan pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS).</p><p>Hasil analisis DOC dan UV menunjukkan peningkatan yang tajam dari kelarutan senyawa organic di awal periode pengamatan yang selanjutnya berkurang seiring dengan waktu secara eksponensial. Jumlah relatif senyawa organic yang terlarut tergantung pada luas permukaan, aktifitas mikrobiologi dan jenis sampel tumbuhan (segar atau kering) yang digunakan. Fluktuasi profil DOC dan UV<sub>254</sub> disebabkan oleh aktifitas mikrobiologi. Diperoleh bahwa daun kering lebih mudah terdegradasi menghasilkan senyawa organic dalam air dibandingkan dengan daun segar. Hasil pyrolysis secara umum menunjukkan bahwa senyawa hidrokarbon aromatic dan fenol (dan turunannya) lebih banyak ditemukan pada residue sampel setelah proses leaching kemungkinan karena adanya senyawa lignin atau aktifitas humifikasi mikrobiologi membuktikan bahwa senyawa-senyawa tersebut merupakan komponen penting dalam proses karakterisasi DOC.</p>

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