High turnover rates of dissolved organic carbon during a spring phytoplankton bloom

Nature ◽  
1991 ◽  
Vol 352 (6336) ◽  
pp. 612-614 ◽  
Author(s):  
David L. Kirchman ◽  
Yoshimi Suzuki ◽  
Christopher Garside ◽  
Hugh W. Ducklow
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Phytoplankton Bloom ◽  
Turnover Rates ◽  
High Turnover ◽  
Spring Phytoplankton Bloom

Synchronous shifts in dissolved organic carbon bioavailability and bacterial community responses over the course of an upwelling-driven phytoplankton bloom

2015 ◽  
Vol 60 (2) ◽  
pp. 657-677 ◽  
Author(s):  
Emma K. Wear ◽  
Craig A. Carlson ◽  
Anna K. James ◽  
Mark A. Brzezinski ◽  
Laura A. Windecker ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Bacterial Community ◽  
Dissolved Organic Carbon ◽  
Phytoplankton Bloom ◽  
Community Responses

scholarly journals Dynamics and sources of dissolved organic carbon during phytoplankton bloom in hypereutrophic Lake Taihu (China)

Limnologica ◽  
2015 ◽  
Vol 54 ◽  
pp. 5-13 ◽  
Author(s):  
Linlin Ye ◽  
Xiaodong Wu ◽  
Bo Liu ◽  
Dezhi Yan ◽  
Fanxiang Kong
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Phytoplankton Bloom ◽  
Lake Taihu

scholarly journals The Seasonal Flux and Fate of Dissolved Organic Carbon Through Bacterioplankton in the Western North Atlantic

2021 ◽  
Vol 12 ◽  
Author(s):  
Nicholas Baetge ◽  
Michael J. Behrenfeld ◽  
James Fox ◽  
Kimberly H. Halsey ◽  
Kristina D. A. Mojica ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
North Atlantic ◽  
Phytoplankton Bloom ◽  
North Atlantic Ocean ◽  
Net Primary Production ◽  
Deep Ocean ◽  
Carbon Demand ◽  
Carbon Pump ◽  
Biological Carbon Pump

The oceans teem with heterotrophic bacterioplankton that play an appreciable role in the uptake of dissolved organic carbon (DOC) derived from phytoplankton net primary production (NPP). As such, bacterioplankton carbon demand (BCD), or gross heterotrophic production, represents a major carbon pathway that influences the seasonal accumulation of DOC in the surface ocean and, subsequently, the potential vertical or horizontal export of seasonally accumulated DOC. Here, we examine the contributions of bacterioplankton and DOM to ecological and biogeochemical carbon flow pathways, including those of the microbial loop and the biological carbon pump, in the Western North Atlantic Ocean (∼39–54°N along ∼40°W) over a composite annual phytoplankton bloom cycle. Combining field observations with data collected from corresponding DOC remineralization experiments, we estimate the efficiency at which bacterioplankton utilize DOC, demonstrate seasonality in the fraction of NPP that supports BCD, and provide evidence for shifts in the bioavailability and persistence of the seasonally accumulated DOC. Our results indicate that while the portion of DOC flux through bacterioplankton relative to NPP increased as seasons transitioned from high to low productivity, there was a fraction of the DOM production that accumulated and persisted. This persistent DOM is potentially an important pool of organic carbon available for export to the deep ocean via convective mixing, thus representing an important export term of the biological carbon pump.

Dissolved organic carbon as a component of the biological pump in the North Atlantic Ocean

1995 ◽  
Vol 348 (1324) ◽  
pp. 161-167 ◽  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
North Atlantic ◽  
Phytoplankton Bloom ◽  
Classical Model ◽  
Global Ocean ◽  
Data Set ◽  
The North ◽  
Biogenic Carbon ◽  
The North Atlantic

The North Atlantic is characterized by strong seasonality in mixed layer depths, resulting in winter recharge of surface layer nutrients and the spring phytoplankton bloom. This is the classical textbook model of seasonal cycles of oceanic biogeochemical processes, but in fact the North Atlantic is the exception rather than the rule. In much of the temperate and subpolar regions of the basin, the vernal accumulation of biomass is accompanied by a marked drawdown of inorganic carbon in the water column and pulses of particle flux to the seafloor. In the classical model, the decline of the C0 2 is balanced by accumulation of biogenic carbon and particle export. The main export mechanisms include sinking of ungrazed but possibly senescent phytoplankton and zooplankton grazing and egestion. Carbon budgets based on observations from the Joint Global Ocean Flux Study North Atlantic Bloom Experiment and Bermuda Atlantic Time Series cannot be closed using the elements of the classical model. That is, the C0 2 drawdown cannot be balanced by biomass accumulation and exports estimated by sediment traps. There are at least three possible routes toward reconciliation: (i) trap estimates are in error and systematically biased; (ii) spatial variability aliasses the observations making budgeting impossible without recourse to coupled three-dimensional models; and/or (iii) the classical model must be abandoned and replaced by a concept in which the accumulation and export of dissolved organic carbon assumes a major role in the North Atlantic carbon balance. At Bermuda, where the most complete data set exists, the weight of the evidence favours the first and third possibilities.

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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