Seasonal variation and controlling factors of air-sea CO2 flux in tropical mangrove estuary: A case study of Dongzhai Harbor, Hainan

doi:10.3969/j.issn.1001-909X.2025.01.008

Abstract

Abstract:

Coastal estuaries are influenced by terrestrial inputs and usually act as sources of atmospheric carbon dioxide (CO₂), whereas mangrove ecosystems generally serve as sinks of atmospheric CO₂. Therefore, accurately measuring the CO₂ emissions at mangrove estuaries is of great significance for constructing regional and global carbon budgets. Dongzhai Harbor locates in the northeastern of Hainan Island, and connects to the Qiongzhou Strait outward, surrounding by 5 major small rivers. Mangroves are mainly distributed in the west and south of Dongzhai Harbor. This study conducted four field surveys in Dongzhaigang, the surrounding major rivers and the adjacent sea areas in December 2022 (dry season), December 2023 (dry season), May 2022 (wet season) and August 2023 (wet season) respectively. The results show that the surface water partial pressure of CO₂ (pCO₂) presents a decreasing trend from rivers to inner and outer harbor. Temperature, river-sea mixing, and biological respiration jointly affect the spatial distributions of pCO₂ in the dry and wet seasons. The CO₂ flux in wet season (8.8±8.2 mmol·m^-2·d^-1) is greater than that in dry season (3.4±3.6 mmol·m^-2·d^-1), and the annual CO₂ flux (6.1±6.3 mmol·m^-2·d^-1) is lower than that in other tropical mangrove estuaries around the world. This study estimates that the estuarine CO₂ emission could offset about 10.4%~21.9% of the carbon sequestration by plants in Dongzhai Harbor.

Key words: mangrove estuary, the partial pressure of CO₂, air-sea CO₂ flux, seasonal variation

CLC Number:

P734.45

WANG Yang, QUAN Xin, ZHUANG Ya, ZHAO Huade, SU Jianzhong. Seasonal variation and controlling factors of air-sea CO₂ flux in tropical mangrove estuary: A case study of Dongzhai Harbor, Hainan[J]. Journal of Marine Sciences, 2025, 43(1): 79-89.

Figures/Tables 7

References 28

[1]	WMO温室气体公报第20期[R]. 2024. https://library.wmo.int/viewer/69466/.
	WMO Greenhouse Gas Bulletin No.20[R]. 2024. https://library.wmo.int/viewer/69466/.
[2]	CHEN C T A, HUANG T H, CHEN Y C, et al. Air-sea exchanges of CO₂ in the world’s coastal seas[J]. Biogeo-sciences, 2013, 10(10): 6509-6544.
[3]	DAI M H, ZHAI W D, CAI W J, et al. Effects of an estuarine plume-associated bloom on the carbonate system in the lower reaches of the Pearl River estuary and the coastal zone of the northern South China Sea[J]. Continental Shelf Research, 2008, 28(12): 1416-1423.
[4]	WANG F M, SANDERS C J, SANTOS I R, et al. Global blue carbon accumulation in tidal wetlands increases with climate change[J]. National Science Review, 2021, 8(9): nwaa296.
[5]	ALONGI D M, MUKHOPADHYAY S K. Contribution of mangroves to coastal carbon cycling in low latitude seas[J]. Agricultural and Forest Meteorology, 2015, 213: 266-272.
[6]	TWILLEY R R, CHEN R H, HARGIS T. Carbon sinks in mangroves and their implications to carbon budget of tropical coastal ecosystems[J]. Water, Air, and Soil Pollution, 1992, 64: 265-288.
[7]	SIPPO J Z, MAHER D T, TAIT D R, et al. Are mangroves drivers or buffers of coastal acidification? Insights from alkalinity and dissolved inorganic carbon export estimates across a latitudinal transect[J]. Global Biogeochemical Cycles, 2016, 30(5): 753-766.
[8]	国家林业局草业局. 国际重要湿地\|海南东寨港国际重要湿地:我国红树林连片面积最大保护区[R]. 2022. http://www.fnrrc.com/hangyedongtai/7241.html.
	National Forestry and Grassland Adminstration. Wetlands of international importance\|dongzhaigang wetland of international importance, Hainan Province: The largest mangrove contiguous area in China [R]. 2022. http://www.fnrrc.com/hangyedongtai/7241.html.
[9]	石彭兰, 王强俊, 谭佐莉, 等. 冬季东寨港微微型浮游植物丰度、分布及影响因素[J]. 海洋与湖沼, 2023, 54(4):1058-1069.
	SHI P L, WANG Q J, TAN Z L, et al. Abundance, distribution and environmental control of picophytoplankton in the winter Dongzhai harbor[J]. Oceanologia et Limnologia Sinica, 2023, 54(4): 1058-1069.
[10]	邢孔敏, 陈石泉, 蔡泽富, 等. 海南东寨港表层沉积物重金属分布特征及污染评价[J]. 海洋科学进展, 2018, 36(3):478-488.
	XING K M, CHEN S Q, CAI Z F, et al. Distribution characteristics and pollution evaluation of heavy metals in surface sediment of Dongzhai Harbor, Hainan Province[J]. Advances in Marine Science, 2018, 36(3): 478-488.
[11]	李伟光, 张京红, 刘少军, 等. 海南岛干旱的气象特征及监测指标[J]. 热带生物学报, 2022, 13(4):324-330.
	LI W G, ZHANG J H, LIU S J, et al. Meteorological characteristics and monitoring index of drought in Hainan Island[J]. Journal of Tropical Biology, 2022, 13(4): 324-330.
[12]	KNAP A H, MICHAELS A F, CLOSE A R, et al. Protocols for the Joint Global Ocean Flux Study (JGOFS) Core Mea-surements[C]. Paris, France, UNESCO-IOC, 1996: 18-32.
[13]	TAKAHASHI T, OLAFSSON J, GODDARD J G, et al. Seasonal variation of CO₂ and nutrients in the high-latitude surface oceans: A comparative study[J]. Global Biogeo-chemical Cycles, 1993, 7(4): 843-878.
[14]	YANG W, GUO X H, CAO Z M, et al. Carbonate dynamics in a tropical coastal system in the South China Sea featuring upwelling, river plumes and submarine groundwater discharge[J]. Science China Earth Sciences, 2022, 65: 2267-2284.
[15]	JIANG L Q, CAI W J, WANG Y C. A comparative study of carbon dioxide degassing in river- and marine-dominated estuaries[J]. Limnology and Oceanography, 2008, 53(6): 2603-2615.
[16]	ZHAI W D, DAI M H, CAI W J, et al. The partial pressure of carbon dioxide and air-sea fluxes in the northern South China Sea in spring, summer and autumn[J]. Marine Chemistry, 2005, 96(1/2): 87-97.
[17]	GUEST M A, CONNOLLY R M, LEE S Y, et al. Mechanism for the small-scale movement of carbon among estuarine habitats: Organic matter transfer not crab movement[J]. Oecologia, 2006, 148(1): 88-96. PMID
[18]	VACHON D, SADRO S, BOGARD M J, et al. Paired O₂-CO₂ measurements provide emergent insights into aquatic ecosystem function[J]. Limnology and Oceanography Letters, 2020, 5(4): 287-294.
[19]	杨旭锋, 于培松, 潘建明, 等. 2019年夏末长江口及其邻近海域走航pCO₂变化及控制机制[J]. 海洋学研究, 2021, 39(4):63-72.
	YANG X F, YU P S, PAN J M, et al. Spatial variation of underway surface pCO₂ and its controls in the Changjiang (Yangtze River) Estuary and adjacent sea area in late summer of 2019 [J]. Journal of Marine Sciences, 2021, 39(4): 63-72.
[20]	JIANG Z P, CAI W J, LEHRTER J, et al. Spring net community production and its coupling with the CO₂ dynamics in the surface water of the northern Gulf of Mexico[J]. Biogeosciences, 2019, 16(18): 3507-3525.
[21]	ROSENTRETER J A, MAHER D T, ERLER D V, et al. Methane emissions partially offset “blue carbon” burial in mangroves[J]. Science Advances, 2018, 4(6): eaao4985.
[22]	SWAIN S, PATTANAIK S, CHANDA A, et al. Multi-annual variability of pCO₂(aq) and air-water CO₂ flux in the mangrove-dominated Dhamra Estuary draining into the Bay of Bengal (India)[J]. Environmental Science and Pollution Research International, 2023, 30(51): 111021-111038.
[23]	LU Z Y, WANG F F, XIAO K, et al. Carbon dynamics and greenhouse gas outgassing in an estuarine mangrove wetland with high input of riverine nitrogen[J]. Biogeo-chemistry, 2023, 162(2): 221-235.
[24]	MARTÍNEZ CASTELLÓN S E, CATTANIO J H, BERRÊDO J F, et al. Spatial and temporal variability of carbon dioxide and methane fluxes in an Amazonian estuary[J]. International Journal of Hydrology, 2021, 5(6): 327-336.
[25]	HO D T, LAW C S, SMITH M J, et al. Measurements of air-sea gas exchange at high wind speeds in the Southern Ocean: Implications for global parameterizations[J]. Geophysical Research Letters, 2006, 33(16): 2006GL026817.
[26]	KREMER J N, REISCHAUER A, D’AVANZO C. Estuary-specific variation in the air-water gas exchange coefficient for oxygen[J]. Estuaries, 2003, 26(4): 829-836.
[27]	2013 Supplement to the 2006 IPCC guidelines for national greenhouse gas inventories:Wetlands[R]. Geneva, IPCC, 2014.
[28]	李翠华, 蔡榕硕, 颜秀花. 2010—2018年海南东寨港红树林湿地碳收支的变化分析[J]. 海洋通报, 2020, 39(4):488-497.
	LI C H, CAI R S, YAN X H. Analysis on the changes of carbon budget of mangrove wetland in Hainan Dongzhaigang during 2010-2018[J]. Marine Science Bulletin, 2020, 39(4): 488-497.

河流	季节	温度/℃	盐度	pH	DIC /(μmol·kg^-1)	TA /(μmol·kg^-1)	DO /(μmol·kg^-1)	DO饱和度/%	AOU /(μmol·kg^-1)	pCO₂ /μatm
演丰西河	干季	18.1	0.10	6.89	1 126	1 048	234	79	62	2 941
演丰西河	湿季	27.9	0.03	6.58	877	757	192	78	54	2 761
演丰东河	干季	18.3	0.09	6.81	854	730	224	76	71	3 657
演丰东河	湿季	29.0	0.02	6.34	750	600	168	68	74	4 318
三江河	干季	18.7	0.06	6.85	749	618	259	90	29	3 501
三江河	湿季	29.4	0.01	6.34	689	549	183	75	57	4 511
演州河	干季	19.0	0.06	6.78	672	535	226	77	69	2 990
演州河	湿季	30.0	0.04	6.27	640	520	143	59	95	4 939
珠溪河	干季	18.1	0.10	6.94	661	544	224	75	76	2 113
珠溪河	湿季	28.8	0.10	6.26	780	693	178	73	64	3 900

河流	季节	温度/℃	盐度	pH	DIC /(μmol·kg^-1)	TA /(μmol·kg^-1)	DO /(μmol·kg^-1)	DO饱和度/%	AOU /(μmol·kg^-1)	pCO₂ /μatm
演丰西河	干季	18.1	0.10	6.89	1 126	1 048	234	79	62	2 941
演丰西河	湿季	27.9	0.03	6.58	877	757	192	78	54	2 761
演丰东河	干季	18.3	0.09	6.81	854	730	224	76	71	3 657
演丰东河	湿季	29.0	0.02	6.34	750	600	168	68	74	4 318
三江河	干季	18.7	0.06	6.85	749	618	259	90	29	3 501
三江河	湿季	29.4	0.01	6.34	689	549	183	75	57	4 511
演州河	干季	19.0	0.06	6.78	672	535	226	77	69	2 990
演州河	湿季	30.0	0.04	6.27	640	520	143	59	95	4 939
珠溪河	干季	18.1	0.10	6.94	661	544	224	75	76	2 113
珠溪河	湿季	28.8	0.10	6.26	780	693	178	73	64	3 900

国家/地区	河口	水体pCO₂ /μatm	CO₂通量 /mmol·m^-2·d^-1
安达曼群岛	Kalighat	1 574~7 888	70.8
安达曼群岛	Wright Myo	1 246~7 703	61.1
澳大利亚	Moreton Bay	9 513~27 188	201.6
澳大利亚	Constant Creek Estuary	449~1 632	21.5~50.5
澳大利亚	Burdekin Estuary	617~13 031	221.0
澳大利亚	Fitzroy Estuary	699~7 947	139.2
澳大利亚	Johnstone Estuary	387~9 744	110.6
澳大利亚	Korogoro Creek		869.0
澳大利亚	Evans Head	997±317	63.0±166.0
澳大利亚	Darwin	622~1 263	40.0
澳大利亚	Hinchinbrook Island	1 341~3 304	30.0
澳大利亚	Jacobs Well	531~5 036	19.0
澳大利亚	Newcastle	404~3 224	46.0
澳大利亚	Seventeen Seventy	314~1 399	10.0
澳大利亚	Barwon Heads		0.4
巴布亚新几内亚	Nagada Creek	540~1 680	43.6
巴哈马	Norman’s Pond	395~690	13.8
巴西	San Francisco Estuary	298~2 007	0.7
巴西	Itacuraca Creek	660~7 700	113.5
百慕大群岛	Mangrove Bay	268~4 823	65.0
肯尼亚	Tana River Delta	230~5 300	58.0
肯尼亚	Gazi Bay	575~6 435	54.3
马达加斯加	Betsiboka	270~1 530	9.1±14.2
美国	Shark River	975~6 016	102.0
坦桑尼亚	Ras Dege	400~5 050	33.7
坦桑尼亚	Mtoni	400~1 700	18.0
印度	Malta Estuary	358~3 033	2.3
印度	Dhamra Estuary	146~751	0.6~218.0
印度	Thakuran Estuary	160~737	0.3
印度	Sundarbans	376~561	4.7
印度	Gaderu Creek	2 215±864	56.0±100.9
印度	Gautami Godavari Estuary	430~4 770	43.4
印度	Mooriganga Estuary	152~1 530	7.7
印度	Saptamukhi Estuary	193~4 000	28.5
印度	Cochin	1 500~3 800	55.1
印度	Hooghly Estuary	70~1 530	-2.8~84.4
越南	Kien Vang	713~8 136	93.5
越南	Tam Giang	528~11 481	135.0
中国	漳江口云霄溪	1 733±605	57.6~115.2
中国	东寨港	426~8 910	12.1(港内+河道)
中国	东寨港	396~8 910	6.1(整个区域)

国家/地区	河口	水体pCO₂ /μatm	CO₂通量 /mmol·m^-2·d^-1
安达曼群岛	Kalighat	1 574~7 888	70.8
安达曼群岛	Wright Myo	1 246~7 703	61.1
澳大利亚	Moreton Bay	9 513~27 188	201.6
澳大利亚	Constant Creek Estuary	449~1 632	21.5~50.5
澳大利亚	Burdekin Estuary	617~13 031	221.0
澳大利亚	Fitzroy Estuary	699~7 947	139.2
澳大利亚	Johnstone Estuary	387~9 744	110.6
澳大利亚	Korogoro Creek		869.0
澳大利亚	Evans Head	997±317	63.0±166.0
澳大利亚	Darwin	622~1 263	40.0
澳大利亚	Hinchinbrook Island	1 341~3 304	30.0
澳大利亚	Jacobs Well	531~5 036	19.0
澳大利亚	Newcastle	404~3 224	46.0
澳大利亚	Seventeen Seventy	314~1 399	10.0
澳大利亚	Barwon Heads		0.4
巴布亚新几内亚	Nagada Creek	540~1 680	43.6
巴哈马	Norman’s Pond	395~690	13.8
巴西	San Francisco Estuary	298~2 007	0.7
巴西	Itacuraca Creek	660~7 700	113.5
百慕大群岛	Mangrove Bay	268~4 823	65.0
肯尼亚	Tana River Delta	230~5 300	58.0
肯尼亚	Gazi Bay	575~6 435	54.3
马达加斯加	Betsiboka	270~1 530	9.1±14.2
美国	Shark River	975~6 016	102.0
坦桑尼亚	Ras Dege	400~5 050	33.7
坦桑尼亚	Mtoni	400~1 700	18.0
印度	Malta Estuary	358~3 033	2.3
印度	Dhamra Estuary	146~751	0.6~218.0
印度	Thakuran Estuary	160~737	0.3
印度	Sundarbans	376~561	4.7
印度	Gaderu Creek	2 215±864	56.0±100.9
印度	Gautami Godavari Estuary	430~4 770	43.4
印度	Mooriganga Estuary	152~1 530	7.7
印度	Saptamukhi Estuary	193~4 000	28.5
印度	Cochin	1 500~3 800	55.1
印度	Hooghly Estuary	70~1 530	-2.8~84.4
越南	Kien Vang	713~8 136	93.5
越南	Tam Giang	528~11 481	135.0
中国	漳江口云霄溪	1 733±605	57.6~115.2
中国	东寨港	426~8 910	12.1(港内+河道)
中国	东寨港	396~8 910	6.1(整个区域)

Seasonal variation and controlling factors of air-sea CO₂ flux in tropical mangrove estuary: A case study of Dongzhai Harbor, Hainan

RichHTML

PDF

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 7

References 28

Related Articles 9

Recommended Articles

Metrics

Comments

[1]	YANG Bo, ZHANG Zhuo, ZHOU Jin, LIN Ziyi, XIE Ziqiang, ZHENG Huina, LIAO Baolin, XIAO Baohua. Variation characteristics and regulation mechanism of pCO₂ in typical subtropical coral reefs area in spring [J]. Journal of Marine Sciences, 2025, 43(1): 90-106.
[2]	SHI Wanli, HU Shijian. Sources and characteristics of seasonal-interannual variability of subsurface undercurrents in the Indonesian Throughflow outflow region [J]. Journal of Marine Sciences, 2024, 42(4): 1-11.
[3]	. Seasonal variation of water masses and current field in the northeastern Beibu Gulf based on observations in 2018-2019 [J]. Journal of Marine Sciences, 2022, 40(3): 73-85.
[4]	MIAO Yanyi, WANG Bin, LI Dewang, JIN Haiyan, JIANG Zhibin, MA Xiao, YU Peisong, CHEN Jianfang, WANG Junyang. The effect of strong wind on air-sea CO₂ flux in the Changjiang River Estuary and its adjacent sea areas [J]. Journal of Marine Sciences, 2020, 38(1): 42-49.
[5]	LI Xiao-hui, LIU Zhen-sheng. Biomass distribution and seasonal variation of zooplankton in the Changjiang Estuary and its adjacent waters [J]. Journal of Marine Sciences, 2017, 35(4): 94-101.
[6]	DING Rui-bin, CHEN Da-ke, JIANG Liang-hong. Variability of Kuroshio axis at Luzon Strait [J]. Journal of Marine Sciences, 2013, 31(2): 16-25.
[7]	LIN Li-ru, ZHAO Hui. Analysis on the relations between sea surface temperature and phy toplankton Chlorophyll-a in the South China Sea [J]. Journal of Marine Sciences, 2012, 30(4): 46-54.
[8]	LI Yi, HE Hai-lun, CHEN Da-ke. Air-sea CO₂ flux in the East China Sea estimated by empirical formula based on the parameters of [J]. Journal of Marine Sciences, 2012, 30(3): 30-40.
[9]	LIN Li-ru, ZHAO Hui. Analysis on the relations between Sea surface temperature and phytoplankton Chlorophyll-a in the South China Sea [J]. Journal of Marine Sciences, 2012, 30(3): 41-48.