Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, whi...Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, which is characterized by high-density shellfish and seaweed aquaculture, the grain size, organic carbon （OC）, total nitrogen （TN）, carbon and nitrogen isotopic composition （δ13C andδ15N） of organic matter in the surface sediment were determined. The results showed that, in August, sedimentary OC and TN ranged from 0.17% to 0.76% and 0.04% to 0.14%, respectively. In November, OC and TN ranged from 0.23% to 0.87% and 0.05% to 0.14%, respectively. There was a significant positive correlation between OC and TN （R=0.98, P＆lt;0.0001）, indicating that OC and TN were homologous. In August, theδ13C andδ15N of organic matter varied from -23.06‰ to -21.59‰ and 5.10‰ to 6.31‰, respectively. In November,δ13C andδ15N ranged from -22.87‰ to -21.34‰ and 5.13‰ to 7.31‰, respectively. This study found that the major sources of sedimentary organic matter were marine shellfish biodeposition, seaweed farming, and soil organic matter. Using a three-end-member mixed model, we estimated that the dominant source of sedimentary organic matter was shellfish biodeposition, with an average contribution rate of 65.53% in August and 43.00% in November. Thus, shellfish farming had a significant influence on the coastal carbon cycle.展开更多
On the basis of the four-season investigation in 23°30′ ~ 33°N and 118°30′ ~ 128°E of the East China Sea from 1997 to 2000, the seasonal distribution of Calanus sinicus was studied with aggregati...On the basis of the four-season investigation in 23°30′ ~ 33°N and 118°30′ ~ 128°E of the East China Sea from 1997 to 2000, the seasonal distribution of Calanus sinicus was studied with aggregation intensity, regression contribution and other statistical methods. It was inferred that C. sinicus＇ s predominance presented from winter to summer, especially in spring and summer, because its dominance amounted to 0.62 and 0.29 respectively. The percent of its abundance in copepod abundance was 76.71% in summer, greater than 66.60% in spring, greater than 19.02% in winter, greater than 4.02% in autumn. The occurrence frequency in winter and spring was 83.08% and 93.89% , higher than that in summer and autumn, 76.71% and 73.87%. Compared with other dominant species of copepods, C. sinicus＇ s contribution to the copepod abundance was obviously greater than that of the other species in winter, summer and spring, but smaller in autumn. C. sinicus tended to have an aggregated distribution. The clumping index peaked in summer （50.19） , followed in spring （19.60） , declined in autumn （13.18） and was the lowest in winter （3.04）. The abundance changed in different seasons and areas, relating to temperature but not salinity in spring and autumn, to salinity but not temperature in summer; to neither temperature nor salinity in winter. In spring and summer, its high abundance area was often located in the mixed water mass formed by the Taiwan Warm Current, the Huanghai Sea Cold Water Mass, the coastal water masses and the Changjiang Dilute Water. In spring and autumn, its abundance was affected by the warm current, as well as the runoff from continental rivers affected it in summer. It can be inferred that C. sinicus was adapted to wide salinity and temperature, as a euryhalinous and eurythermous species in the East China Sea.展开更多
基金The Joint Fund Project of National Fund Committee and Shandong Province under contract No.U1406403the State Oceanic Administration Project of China under contract Nos DOMEP(MEA)-01-01 and DOMEP(MEA)-02
文摘Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, which is characterized by high-density shellfish and seaweed aquaculture, the grain size, organic carbon （OC）, total nitrogen （TN）, carbon and nitrogen isotopic composition （δ13C andδ15N） of organic matter in the surface sediment were determined. The results showed that, in August, sedimentary OC and TN ranged from 0.17% to 0.76% and 0.04% to 0.14%, respectively. In November, OC and TN ranged from 0.23% to 0.87% and 0.05% to 0.14%, respectively. There was a significant positive correlation between OC and TN （R=0.98, P＆lt;0.0001）, indicating that OC and TN were homologous. In August, theδ13C andδ15N of organic matter varied from -23.06‰ to -21.59‰ and 5.10‰ to 6.31‰, respectively. In November,δ13C andδ15N ranged from -22.87‰ to -21.34‰ and 5.13‰ to 7.31‰, respectively. This study found that the major sources of sedimentary organic matter were marine shellfish biodeposition, seaweed farming, and soil organic matter. Using a three-end-member mixed model, we estimated that the dominant source of sedimentary organic matter was shellfish biodeposition, with an average contribution rate of 65.53% in August and 43.00% in November. Thus, shellfish farming had a significant influence on the coastal carbon cycle.
基金This study was funded by the Major Research Plan of the National Natural Science Foundation of China under contract No.90511005the National Key Science Foundation Research"973"Project of the Ministry of Science and Technology of China under contract No.2001CB409700-07.
文摘On the basis of the four-season investigation in 23°30′ ~ 33°N and 118°30′ ~ 128°E of the East China Sea from 1997 to 2000, the seasonal distribution of Calanus sinicus was studied with aggregation intensity, regression contribution and other statistical methods. It was inferred that C. sinicus＇ s predominance presented from winter to summer, especially in spring and summer, because its dominance amounted to 0.62 and 0.29 respectively. The percent of its abundance in copepod abundance was 76.71% in summer, greater than 66.60% in spring, greater than 19.02% in winter, greater than 4.02% in autumn. The occurrence frequency in winter and spring was 83.08% and 93.89% , higher than that in summer and autumn, 76.71% and 73.87%. Compared with other dominant species of copepods, C. sinicus＇ s contribution to the copepod abundance was obviously greater than that of the other species in winter, summer and spring, but smaller in autumn. C. sinicus tended to have an aggregated distribution. The clumping index peaked in summer （50.19） , followed in spring （19.60） , declined in autumn （13.18） and was the lowest in winter （3.04）. The abundance changed in different seasons and areas, relating to temperature but not salinity in spring and autumn, to salinity but not temperature in summer; to neither temperature nor salinity in winter. In spring and summer, its high abundance area was often located in the mixed water mass formed by the Taiwan Warm Current, the Huanghai Sea Cold Water Mass, the coastal water masses and the Changjiang Dilute Water. In spring and autumn, its abundance was affected by the warm current, as well as the runoff from continental rivers affected it in summer. It can be inferred that C. sinicus was adapted to wide salinity and temperature, as a euryhalinous and eurythermous species in the East China Sea.
