Preliminary study on DOC behavior and mechanism in the estuarine bloom zones
LIN Jian-rong
1. School of EnvironmentaL Science and Engineering, Xiamen University Tan Kah Kee College, Zhangzhou 363105, China;
2. Key Laboratory of Estuarine Ecological Security and Environmental Health of Fujian Province University (Xiamen University Tan Kah Kee College), Zhangzhou 363105, China
Abstract:The phytoplankton growth has a tight relationship with the carbon fixation, hence the study of mechanism can discover the process of marine carbon cycle. It is believed that dissolved organic carbon (DOC, measured by High Temperature Combustion Method) is actively released by phytoplankton to compensate for the luxury carbon uptake in the bloom zone. The study results in several bloom zones in Changjiang estuary and Pearl River estuary mid-high salinity zone (salinity ranged from 10 to 30), however, showed the similar DOC concentration in these blooms and non-bloom zones. In the meantime, the total organic carbon (TOC) discovered increased significantly, TOCs were 60~140 μmol/L and >110 μmol/L higher than DOCs in the two estuaries, respectively, indicating most of the fixed carbon existing as particular organic carbon (POC). The incubation data indicated that only 10% of fixed carbon existing as DOC (i.e., 90% of the fixed carbon existing as POC) in non-sterilized seawater; on the contrary, >80% of the fixed-carbon existing as DOC (i.e., ~20% of the fixed carbon existing as POC) in sterilized seawater, suggesting bacteria take an important role in the decomposition of the phytoplankton produced DOC in the bloom zones in the two estuaries.
LIN Jian-rong. Preliminary study on DOC behavior and mechanism in the estuarine bloom zones[J]. Marine Environmental Science, 2017, 36(5): 676-681,718.
FRY B,HOPKINSON JR C S,NOLIN A,et al.Long-term decomposition of DOC from experimental diatom blooms[J].Limnology and Oceanography,1996,41(6):1344-1347.
[3]
RIVKIN R B,ANDERSON M R.Inorganic nutrient limitation of oceanic bacterioplankton[J].Limnology and Oceanography,1997,42(4):730-740.
KNAP A H,MICHAELS A F,STEINBERG D K,et al.BATS methods manual,version 4,April 1997[Z].Woods Hole,MA:United States JGOFS Planning and Coordination Office,1997.
[12]
STEINBERG D K,GOLDTHWAIT S A,HANSELL D A.Zooplankton vertical migration and the active transport of dissolved organic and inorganic nitrogen in the Sargasso Sea[J].Deep Sea Research Part I:Oceanographic Research Papers,2002,49(8):1445-1461.
[13]
PETERSON M L,LANG S Q,AUFDENKAMPE A K,et al.Dissolved organic carbon measurement using a modified high-temperature combustion analyzer[J].Marine Chemistry,2003,81(1/2):89-104.
[14]
SUGIMURA Y,SUZUKI Y.A high-temperature catalytic oxidation method for the determination of non-volatile dissolved organic carbon in seawater by direct injection of a liquid sample[J].Marine Chemistry,1988,24(2):105-131.
[15]
SUZUKI Y,TANOUE E,ITO H.A high-temperature catalytic oxidation method for the determination of dissolved organic carbon in seawater:analysis and improvement[J].Deep Sea Research Part A.Oceanographic Research Papers,1992,39(2):185-198.
[16]
SHARP J H,BENNER R,BENNETT L,et al.Analyses of dissolved organic carbon in seawater:the JGOFS EqPac methods comparison[J].Marine Chemistry,1995,48(2):91-108.
[17]
SHARP J H,CARLSON C A,PELTZER E T,et al.Final dissolved organic carbon broad community intercalibration and preliminary use of DOC reference materials[J].Marine Chemistry,2002,77(4):239-253.
[18]
STORCH T A,SAUNDERS G W.Phytoplankton extracellular release and its relation to the seasonal cycle of dissolved organic carbon in a eutrophic lake[J].Limnology and Oceanography,1978,23(1):112-119.
[19]
COLE J J,LIKENS G E,STRAYER D L.Photosynthetically produced dissolved organic carbon:An important carbon source for planktonic bacteria[J].Limnology and Oceanography,1982,27(6):1080-1090.
[20]
OLIVER J L,BARBER R T,SMITH JR W O,et al.The heterotrophic bacterial response during the Southern Ocean Iron Experiment (SOFeX)[J].Limnology and Oceanography,2004,49(6):2129-2140.
[21]
VAN DEN MEERSCHE K,MIDDELBURG J J,SOETAERT K,et al.Carbon-nitrogen coupling and algal-bacterial interactions during an experimental bloom:modeling a 13C tracer experiment[J].Limnology and Oceanography,2004,49(3):862-878.