1. Key Laboratory of Coast and Island Development of Ministry of Education, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, China;
2. State Research Centre For Island Exploitation And Management, Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China;
3. State Key Laboratory of Estuarine and Coastal Research, Institute of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
Abstract：In order to investigate the variations of organic matter in surface sediments over Changjiang estuary and Hangzhou bay,112 surficial sediments were collected,and the content of total organic carbon(TOC),total nitrogen(TN),stable carbon isotope(δ13C) and stable nitrogen isotope(δ15N) were analyzed.Two regions were identified within the study,which were subaqueous Yangtze delta in the north and Zhe-Min inner shelf deposition in the south.The results indicateed that TOC and TN,whose higher content were found around 29°N ranging from 122°E to 123°E,increased at first and then decreased from land to sea in subaqueous Yangtze delta,and an increasing trend was observed to Zhe-Min inner shelf deposition.δ13C,increasing towards sea,in the north was lighter than that of south.Since 2006,TOC and TN had significantly decreased,and δ13C had become lighter,the distribution of TOC or TN showed a more uniform pattern especially in Changjiang estuary,which performed more apparently in the west of 123.5°E.
CHAO Hai-juan,GAO Jian-hua,JIA Jian-jun et al. Change of organic matter sources in surface sediments over Changjiang estuary and its adjacent waters[J]. Marine Environmental Science, 2017, 36(2): 237-242.
LIU J P,XU K H,LI A C,et al.Flux and fate of Yangtze River sediment delivered to theEast China Sea[J].Geomorphology,2007,85(3/4):208-224.
[2]
ZHANG J.Heavy metal compositions of suspended sediments in the Changjiang (Yangtze River) estuary:significance of riverine transport to the ocean[J].Continental Shelf Research,1999,19(12):1521-1543.
[3]
WU Y,ZHANG J,LIU S M,et al.Sources and distribution of carbon within theYangtze River system[J].Estuarine,Coastal and Shelf Science,2007,71(1/2):13-25.
[4]
GRAHAM M C,EAVES M A,FARMER J G,et al.A study of carbon and nitrogen stable isotope and elemental ratios as potential indicators of source and fate of organic matter in sediments of the ForthEstuary,Scotland[J].Estuarine,Coastal and Shelf Science,2001,52(3):375-380.
GAO S,WANG Y P.Changes in material fluxes from the Changjiang River and their implications on the adjoining continental shelf ecosystem[J].Continental Shelf Research,2008,28(12):1490-1500.
JIA JJ,GAO J H,LIU Y F,et al.Environmental changes in Shamei Lagoon,Hainan Island,China:interactions between natural processes and human activities[J].Journal of Asian Earth Sciences,2012,52:158-168.
[10]
LAMB A L,WILSON G P,LENG M J.A review of coastal palaeoclimate and relative sea-level reconstructions using δ 13C and C/N ratios in organic material[J].Earth-ScienceReviews,2006,75(1/2/3/4):29-57.
[11]
CIFUENTES L A,COFFIN R B,SOLORZANO L,et al.Isotopic and elemental variations of carbon and nitrogen in a Mangrove Estuary[J].Estuarine,Coastal & Shelf Science,1996,43(6):781-800.
LI G,WANG X T,YANG Z F,et al.Dam-triggered organic carbon sequestration makes the Changjiang (Yangtze) river basin (China) a significant carbon sink[J].Journal of Geophysical Research:Biogeosciences,2015,120(1):39-53.
[21]
GAO J H,JIA J,WANG Y P,et al.Variations in quantity,composition and grain size of Changjiang sediment discharging into the sea in response to human activities[J].Hydrology and Earth System Sciences,2015,19(2):645-655.
[22]
LI D,YAO P,BIANCHI T S,et al.Organic carbon cycling in sediments of the Changjiang Estuary and adjacent shelf:implication for the influence of Three Gorges Dam[J].Journal of Marine Systems,2014,139:409-419.
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