Seasonal variations in numerical abundance, cell diameter and population carbon biomass of the heterotrophic dinoflagellate Noctiluca scintillans were studied for 10 years from 2004 to 2013 in Jiaozhou Bay and adjacen...Seasonal variations in numerical abundance, cell diameter and population carbon biomass of the heterotrophic dinoflagellate Noctiluca scintillans were studied for 10 years from 2004 to 2013 in Jiaozhou Bay and adjacent coastal Yellow Sea, China, and their ecological functions were evaluated. In both areas, N. scintillans occurred throughout the year and demonstrated an essentially similar seasonality; the cell abundance increased rapidly from the winter minimum to an annual peak in late spring and early summer, and decreased gradually toward the autumn-winter minimum. The peak abundance differed by years, and there was no consistent trend in long-term numerical variations. The cell diameter also showed a seasonal fluctuation, being larger in spring and early summer than the other seasons. Estimated carbon biomass of N. scintillans population reached to a peak as high as 90.3 mg C/m^3, and occasionally exceed over phytoplankton and copepod biomass. Our results demonstrate that N. scintillans in northwestern Yellow Sea displays the seasonal phenology almost identical to the populations in other temperate regions, and play important trophic roles as a heterotroph to interact with sympatric phytoplankton and copepods.展开更多
The concentration and distribution of three persistent organic pollutants （hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polyehlorinated biphenyls （PCBs）） was assessed in tidal fia...The concentration and distribution of three persistent organic pollutants （hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polyehlorinated biphenyls （PCBs）） was assessed in tidal fiat sediments collected from the south bank of Hangzhou Bay, China from 2009 to 2013. Gas chromatography coupled to triple quadrupole mass spectrometry （GC-MS/MS） was used for analysis, based on United States Environmental Protection Agency methods EPAS080A, EPA8081B, and EPA3550B. The results showed that the levels of HCHs, DDTs and PCBs decreased in the order of DDTs 〉 HCHs 〉 PCBs, and their mass fractions ranged from 0.29-32.91, 0.09-13.19 and 0.16-4.10 ktg/kg （dry mass）, respectively. The levels of HCHs, DDTs and PCBs decreased slowly from 2009 to 2013, with considerably greater concentrations in winter than in spring and summer. In this study area, the concentrations of DDTs and HCHs decreased gradually towards the mouth of Hangzhou Bay, while the concentrations of PCBs were related to changes in the local economy. In addition, the sources of HCHs and DDTs were identified as atmospheric precipitation and historical residues, Finally, we predicted that PCBs pollution primarily originated from Aroclor 1254（Lot A4）, which might root in the illegal demolition and stacking of abandoned paint, transformer or electronic equipment in the south bank of Hangzhou Bay.展开更多
基金Supported by the State Key Program of National Natural Science Foundation of China(No.41230963)the NSFC-Shandong Joint Fund for Marine Ecology and Environmental Sciences(No.U1606404)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA11020305)the President’s International Fellowship Initiative(PIFI)of the Chinese Academy of Sciences(No.2016VBA078)to SUNSong
文摘Seasonal variations in numerical abundance, cell diameter and population carbon biomass of the heterotrophic dinoflagellate Noctiluca scintillans were studied for 10 years from 2004 to 2013 in Jiaozhou Bay and adjacent coastal Yellow Sea, China, and their ecological functions were evaluated. In both areas, N. scintillans occurred throughout the year and demonstrated an essentially similar seasonality; the cell abundance increased rapidly from the winter minimum to an annual peak in late spring and early summer, and decreased gradually toward the autumn-winter minimum. The peak abundance differed by years, and there was no consistent trend in long-term numerical variations. The cell diameter also showed a seasonal fluctuation, being larger in spring and early summer than the other seasons. Estimated carbon biomass of N. scintillans population reached to a peak as high as 90.3 mg C/m^3, and occasionally exceed over phytoplankton and copepod biomass. Our results demonstrate that N. scintillans in northwestern Yellow Sea displays the seasonal phenology almost identical to the populations in other temperate regions, and play important trophic roles as a heterotroph to interact with sympatric phytoplankton and copepods.
基金Supported by the Medical and Health Science Research Foundation of Zhejiang Province(No.2011RCA031)the Agriculture and Social Development Funds of Ningbo,China(No.2012C0030)
文摘The concentration and distribution of three persistent organic pollutants （hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polyehlorinated biphenyls （PCBs）） was assessed in tidal fiat sediments collected from the south bank of Hangzhou Bay, China from 2009 to 2013. Gas chromatography coupled to triple quadrupole mass spectrometry （GC-MS/MS） was used for analysis, based on United States Environmental Protection Agency methods EPAS080A, EPA8081B, and EPA3550B. The results showed that the levels of HCHs, DDTs and PCBs decreased in the order of DDTs 〉 HCHs 〉 PCBs, and their mass fractions ranged from 0.29-32.91, 0.09-13.19 and 0.16-4.10 ktg/kg （dry mass）, respectively. The levels of HCHs, DDTs and PCBs decreased slowly from 2009 to 2013, with considerably greater concentrations in winter than in spring and summer. In this study area, the concentrations of DDTs and HCHs decreased gradually towards the mouth of Hangzhou Bay, while the concentrations of PCBs were related to changes in the local economy. In addition, the sources of HCHs and DDTs were identified as atmospheric precipitation and historical residues, Finally, we predicted that PCBs pollution primarily originated from Aroclor 1254（Lot A4）, which might root in the illegal demolition and stacking of abandoned paint, transformer or electronic equipment in the south bank of Hangzhou Bay.
