气候变化领域集成服务门户(CCPortal): Hypoxia and its feedback response to algal blooms and CH4 emissions in subtropical reservoirs

CCPortal

DOI	10.3389/fevo.2023.1297047
	Hypoxia and its feedback response to algal blooms and CH4 emissions in subtropical reservoirs
	Ji, Daobin; Han, Yanxing; Long, Lianghong; Xin, Xiaokang; Xu, Hui; Qiu, Siqian; Meng, Jianghuai; Zhao, Xingxing; Huang, Yanan; Liu, Defu
发表日期	2024
ISSN	2296-701X
起始页码	11
卷号	11
英文摘要	Anthropogenic nutrient input stimulates surface eutrophication and algal blooms and thus exacerbates oxygen depletion and hypoxia in aquatic ecosystems. However, existing studies have paid little attention on the understanding of the feedback relationships among oxygen consumption, algal succession and greenhouse gas effect after river damming, particularly in Three Gorges Reservoir. This field work investigated the thermal stratification, water quality and phytoplankton in four tributaries (Pengxi Bay (PXB), Daning Bay (DNB), Shennong Bay (SNB), and Xiangxi Bay (XXB)) of the Three Gorges Reservoir (TGR) in spring (April 25-28, 2022), and explored the drivers of hypoxia and its feedback response to algal blooms and methane (CH4) emissions. The results showed that during the observation period, DO, thermal stratification, and algal blooms were more severe in PXB. The high Chemical Oxygen Demand (CODMn) (11.27 mg center dot L-1) and Dissolved Organic Carbon (DOC) content (7.56 mg center dot L-1) in PXB were the main causes of the progressive hypoxia. Furthermore, stronger density stratification in PXB inhibited the vertical supply of DO and accelerated bottom hypoxia. But the downslope density current replenished bottom DO in the upper reaches of the DNB, SNB, and XXB. The CH4 concentration was generally higher in hypoxia zone, especially in where cyanobacteria are the dominant species (eg., PX03 and PX04). Dam construction led to the succession of algal-dominant species, exerting a significant influence on the river carbon cycle. The expansion of cyanobacterial blooms and the consequence of metabolic substrates increase are gradually increasing oxygen deprivation, even hypoxia, and enhancing CH4 production in rivers. These findings suggest that the succession of algal-dominant species caused by river damming has a pronounced positive feedback effect on reservoir hypoxia processes and greenhouse effect.
英文关键词	dissolved oxygen stratification; hypoxia; algal bloom; greenhouse gas; TGR
语种	英语
WOS研究方向	Environmental Sciences & Ecology
WOS类目	Ecology
WOS记录号	WOS:001145072300001
来源期刊	FRONTIERS IN ECOLOGY AND EVOLUTION
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/301981
作者单位	China Three Gorges University; China Three Gorges University; Ministry of Water Resources; Yangtze River Water Resources Protection Bureau; Hubei University of Technology
推荐引用方式 GB/T 7714	Ji, Daobin,Han, Yanxing,Long, Lianghong,et al. Hypoxia and its feedback response to algal blooms and CH4 emissions in subtropical reservoirs[J],2024,11.
APA	Ji, Daobin.,Han, Yanxing.,Long, Lianghong.,Xin, Xiaokang.,Xu, Hui.,...&Liu, Defu.(2024).Hypoxia and its feedback response to algal blooms and CH4 emissions in subtropical reservoirs.FRONTIERS IN ECOLOGY AND EVOLUTION,11.
MLA	Ji, Daobin,et al."Hypoxia and its feedback response to algal blooms and CH4 emissions in subtropical reservoirs".FRONTIERS IN ECOLOGY AND EVOLUTION 11(2024).