Ebullition was a major pathway of methane emissions from the aquaculture ponds in southeast China

WATER RESEARCH

卷:184

Article

Yang, Ping^1,2  Zhang, Yifei^1,2  Yang, Hong^3,4,5  Guo, Qianqian^1,2  Lai, Derrick Y. F.⁶  Zhao, Guanghui¹  Li, Ling¹  Tong, Chuan^1,2 

[1] Fujian Normal Univ, Minist Educ, Key Lab Humid Subtrop Ecogeog Proc, Fuzhou 350007, Peoples R China

[2] Fujian Normal Univ, Sch Geog Sci, Fuzhou 350007, Peoples R China

[3] Fujian Normal Univ, Coll Environm Sci & Engn, Fuzhou 350007, Peoples R China

[4] Nanjing Univ Informat Sci & Technol, Sch Environm Sci & Engn, Collaborat Innovat Ctr Atmospher Environm & Equip, Jiangsu Key Lab Atmospher Environm Monitoring & P, 219 Ningliu Rd, Nanjing 210044, Peoples R China

[5] Univ Reading, Dept Geog & Environm Sci, Reading RG6 6AB, Berks, England

[6] Chinese Univ Hong Kong, Dept Geog & Resource Management, Shatin, Hong Kong, Peoples R China

关键词: Methane (CH4);    Ebullition;    Greenhouse gas;    Spatiotemporal variation;    Aquaculture pond;    Subtropical estuary;   

DOI  :  10.1016/j.watres.2020.116176

来源: Elsevier

【 摘 要 】

Aquaculture ponds are hotspots of carbon cycling and important anthropogenic sources of the potent greenhouse gas methane (CH4). Despite the importance of CH4 ebullition in aquatic ecosystems, its magnitude and spatiotemporal variations in aquaculture ponds remain poorly understood. In this study, we determined the rates and spatiotemporal variations of ebullitive CH4 emissions from three mariculture ponds during the aquaculture period of two years at a subtropical estuary in southeast China. Our results showed that the mean ebullitive CH4 flux from the studied ponds was 14.9 mg CH4 m(-2) h(-1) during the aquaculture period and accounted for over 90% of the total CH4 emission, indicating the importance of ebullition as a major CH4 transport mechanism. Ebullitive CH4 emission demonstrated a clear seasonal pattern, with a peak value during the middle stage of aquaculture. Sediment temperature was found to be an important factor influencing the seasonal variations in CH4 ebullition. Ebullitive CH4 fluxes also exhibited considerable spatial variations within the ponds, with 49.7-71.8% of the whole pond CH4 ebullition being detected in the feeding zone where the large loading of sediment organic matter fueled CH4 production. Aquaculture ponds have much higher ebullitive CH4 effluxes than other aquatic ecosystems, which indicated the urgency to mitigate CH4 emission from aquaculture activities. Our findings highlighted that the importance of considering the large spatiotemporal variations in ebullitive CH4 flux in improving the accuracy of large-scale estimation of CH4 fluxes in aquatic ecosystems. Future studies should be conducted to characterize CH4 ebullitive fluxes over a greater number and diversity of aqua culture ponds and examine the mechanisms controlling CH4 ebullition in aquatic ecosystems. (c) 2020 Published by Elsevier Ltd.

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