| 摘要: |
| 根据2018年7月、11月和2019年1月、4月对广东考洲洋牡蛎养殖海域进行4个季节调查获得的pH、溶解无机碳(DIC)、水温、盐度、溶解氧(DO)及叶绿素a(Chl-a)等数据，估算该区域表层海水溶解无机碳体系各分量的浓度、浮游植物固碳强度(PP)、表层海水CO2分压(pCO2)和海-气界面CO2交换通量(F)，分析牡蛎养殖活动对养殖区碳循环的影响。结果表明：牡蛎养殖区表层海水中Chl-a、DIC、HCO- 3 和PP显著低于非养殖区；养殖淡季表层海水中pH、DO、DIC、HCO- 3 和CO2- 3 显著大于养殖旺季，养殖旺季的pCO2和F显著大于养殖淡季。牡蛎养殖区表层海水夏季、秋季、冬季和春季的F值平均值分别是(42.04±9.56)、(276.14±52.55)、(-11.59±18.15)和(-13.02±6.71)mmol/(m2·d)，冬季各站位F值离散度较大，其中位数是-10.73mmol/(m2·d)。在全年尺度，表层海水pCO2及F与水温呈显著正相关，与盐度呈显著负相关。在非养殖区，浮游植物光合作用可能对影响表层海水pCO2及F起主导作用。养殖牡蛎钙化、呼吸作用等生理因素释放的CO2对表层海水pCO2及F未产生显著影响。考洲洋养殖海域养殖旺季为CO2的源，养殖淡季整体为CO2的弱汇。 |
| 关键词: 溶解无机碳 pCO2 CO2交换通量 牡蛎养殖 考洲洋 |
| DOI： |
| 分类号:Q176；X55 |
| 基金项目:广东省促进经济发展专项资金(GDME-2018E006)；广东省渔业生态环境重点实验室开放(No. FEEL-2017-6) |
|
| Temporal and spatial variation of sea-air CO2 flux in oyster aquaculture area of Kaozhou Bay |
|
PENG Pengfei1, MA Yuan1, SHI Rongjun2, WANG Di1, XU Xin1, YAN Bin1
|
|
1.South China Sea Marine Survey and Technology Center,State Oceanic Administration;2.South China Sea Fisheries Research Institute,Chinese Academy of Fisheries Sciences
|
| Abstract: |
| Based on the investigation data of pH, dissolved inorganic carbon(DIC), seawater temperature, salinity, dissolved oxygen(DO) , chlorophyll a(Chl-a) and other data, during four seasons from July and November 2018 and January and April 2019 in oyster aquaculture area of Kaozhou Bay in Guangdong, the concentration of each component of dissolved inorganic carbon system, carbon fixed production of phytoplankton(PP), pCO2 and sea-air CO2 flux(F) were estimated, the influence of carbon cycle by oyster aquaculture activities in oyster aquaculture area was analyzed. The results showed that the Chl-a, DIC, HCO- 3 and PP in surface seawater in oyster aquaculture area were significantly lower than those in non-culture area. The pH, DO, DIC, HCO- 3 and CO2- 3 in surface seawater in off-season were significantly higher than those in peak season, and the pCO2 and F in peak season were significantly higher than those in off-season. The average F of surface seawater in oyster culture area in summer, autumn, winter and spring was (42.04±9.56)、(276.14±52.55)、(-11.59±18.15) and (-13.02±6.71) mmol/(m2·d), respectively. The dispersion of F in oyster culture area in winter was large, and the median was -10.73 mmol/(m2·d). In the whole year, pCO2 and F of surface sea water were significantly positively correlated with water temperature and negatively correlated with salinity. In non-culture area, phytoplankton photosynthesis may played a leading role in affecting pCO2 and F of surface seawater. The CO2 released by physiological factors such as calcification and respiration of cultured oysters had no significant effect on pCO2 and F in surface water. Kaozhou Bay was the source of CO2 in peak season and the weak sink of CO2 in the off-season. |
| Key words: DIC pCO2 CO2 flux oyster aquaculture Kaozhou Bay |