title: [Relationship between pCO2 and algal biomass in Xiangxi Bay in spring].
abstract: Water temperature (WT), pH, HCO3-, dissolved oxygen and the concentration of Chl-a in Xiangxi Bay were measured in spring. The partial pressure of carbon dioxide was calculated by the chemical balance and Henry's Law while CO2 flux by the thin-layer diffusion model. Results showed that pCO2 of surface water in Xiangxi Bay varied from 8.34 microatm to 168.70 microatm with a mean of 49.01 microatm. pCO2 increased along the stream with Chl-a decreased from upstream to the estuary. The mean of pCO2 was 117.92 microatm on the diurnal scale, ranging from 74.43 microatm to 168.70 microatm, and the mean concentration of Chl-a was 3.04 mg x m(-3) with the range from 2.22 mg x m(-3) to 4.55 mg x m(-3). There were statistically significant negative correlations between values for pCO2 and Chl-a (r = -0.844, P < 0.01). Phytoplankton photosynthesis in Xiangxi Bay played a crucial role in the spatial and temporal distribution of pCO2. The undersaturation observed suggests that surface waters in Xiangxi Bay represented a sink for atmospheric CO2 in spring, and the exchange rate of CO2 was estimated to be -35.17 mmol x (m2 x d)(-1).
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. yxg1987@126.com
authors.forename: Xi-gong
authors.initials: XG
authors.lastname: Yuan
authors.forename: Wen-min
authors.initials: WM
authors.lastname: Huang
authors.forename: Yong-hHong
authors.initials: YH
authors.lastname: Bi
authors.forename: Zheng-yu
authors.initials: ZY
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Kong-xian
authors.initials: KX
authors.lastname: Zhu
mesh_terms: D061006:Bays; D018533:Biomass; D002245:Carbon Dioxide / Q000032:analysis; D002681:China; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D000458:Cyanobacteria / Q000254:growth & development*; D004784:Environmental Monitoring; D005068:Eutrophication; D010839:Phytoplankton / Q000254:growth & development*; D045483:Rivers; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply
chemical_list: D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D002245:Carbon Dioxide; D000077194:Chlorophyll A