Articles | Volume 15, issue 4
https://doi.org/10.5194/bg-15-997-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-15-997-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
20 Feb 2018
Research article |
| 20 Feb 2018
Tidal variability of nutrients in a coastal coral reef system influenced by groundwater
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
Shuling Wang
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
Zhangyong Wang
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
Wenping Jing
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
deceased
Yi Xu
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
Zhouling Zhang
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
Ehui Tan
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
Minhan Dai
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China
College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
Related authors
Yanmin Wang, Xianghui Guo, Guizhi Wang, Lifang Wang, Tao Huang, Yan Li, Zhe Wang, and Minhan Dai
EGUsphere, https://doi.org/10.5194/egusphere-2023-3155, https://doi.org/10.5194/egusphere-2023-3155, 2024
Preprint archived
Short summary
Short summary
This study reports higher nutrient release in fish farming system compared to river inputs and other sources with implications for coastal environment. DIN and DIP variation in Sansha Bay are dominated by mariculture activity relative to river input during spring. The N/P budget shows that 52.8 ± 4.7 % of DIN and 33.0 ± 3.7 % of DIP released from fish feeds exceeded other nutrient inputs. Co-culture strategies (e.g., of fish, kelp and oysters) allow effective mitigation of environmental impacts.
Zhixuan Wang, Guizhi Wang, Xianghui Guo, Yan Bai, Yi Xu, and Minhan Dai
Earth Syst. Sci. Data, 15, 1711–1731, https://doi.org/10.5194/essd-15-1711-2023, https://doi.org/10.5194/essd-15-1711-2023, 2023
Short summary
Short summary
We reconstructed monthly sea surface pCO2 data with a high spatial resolution in the South China Sea (SCS) from 2003 to 2020. We validate our reconstruction with three independent testing datasets and present a new method to assess the uncertainty of the data. The results strongly suggest that our reconstruction effectively captures the main features of the spatiotemporal patterns of pCO2 in the SCS. Using this dataset, we found that the SCS is overall a weak source of atmospheric CO2.
Guizhi Wang, Samuel S. P. Shen, Yao Chen, Yan Bai, Huan Qin, Zhixuan Wang, Baoshan Chen, Xianghui Guo, and Minhan Dai
Earth Syst. Sci. Data, 13, 1403–1417, https://doi.org/10.5194/essd-13-1403-2021, https://doi.org/10.5194/essd-13-1403-2021, 2021
Short summary
Short summary
This study reconstructs a complete field of summer sea surface partial pressure of CO2 (pCO2) over the South China Sea (SCS) with a 0.5° resolution in the period of 2000–2017 using the scattered underway pCO2 observations. The spectral optimal gridding method was used in this reconstruction with empirical orthogonal functions computed from remote sensing data. Our reconstructed data show that the rate of sea surface pCO2 increase in the SCS is 2.4 ± 0.8 µatm yr-1 during 2000–2017.
Jialu Huang, Moriaki Yasuhara, He Wang, Pedro Julião Jimenez, Jiying Li, and Minhan Dai
EGUsphere, https://doi.org/10.5194/egusphere-2025-138, https://doi.org/10.5194/egusphere-2025-138, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
We investigated the abundance, diversity, composition, and distribution of ostracod (a meiobenthic group) and their interactions with eutrophication and pollution through high resolution sampling of surface sediment in Deep Bay, a small semi-enclosed riverine bay adjacent to two of the world’s most populated cities, Hong Kong and Shenzhen. The results support the idea that ostracod is a useful bioindicator of coastal benthic ecosystems shaped by distinct environmental problems.
Yuye Han, Zvi Steiner, Zhimian Cao, Di Fan, Junhui Chen, Jimin Yu, and Minhan Dai
EGUsphere, https://doi.org/10.5194/egusphere-2024-3492, https://doi.org/10.5194/egusphere-2024-3492, 2024
Short summary
Short summary
Coccolithophore calcite accounts for a major fraction of particulate inorganic carbon (PIC) standing stocks in the western North Pacific, with a markedly higher contribution in the oligotrophic subtropical gyre than in the Kuroshio-Oyashio transition region, which highlights the importance of coccolithophores for PIC production in the pelagic ocean. We also found extensive dissolution of coccolithophore calcite in the oversaturated shallow waters primarily driven by microbial metabolic activity.
Yanmin Wang, Xianghui Guo, Guizhi Wang, Lifang Wang, Tao Huang, Yan Li, Zhe Wang, and Minhan Dai
EGUsphere, https://doi.org/10.5194/egusphere-2023-3155, https://doi.org/10.5194/egusphere-2023-3155, 2024
Preprint archived
Short summary
Short summary
This study reports higher nutrient release in fish farming system compared to river inputs and other sources with implications for coastal environment. DIN and DIP variation in Sansha Bay are dominated by mariculture activity relative to river input during spring. The N/P budget shows that 52.8 ± 4.7 % of DIN and 33.0 ± 3.7 % of DIP released from fish feeds exceeded other nutrient inputs. Co-culture strategies (e.g., of fish, kelp and oysters) allow effective mitigation of environmental impacts.
Yifan Ma, Kuanbo Zhou, Weifang Chen, Junhui Chen, Jin-Yu Terence Yang, and Minhan Dai
Biogeosciences, 20, 2013–2030, https://doi.org/10.5194/bg-20-2013-2023, https://doi.org/10.5194/bg-20-2013-2023, 2023
Short summary
Short summary
We distinguished particulate organic carbon (POC) export fluxes out of the nutrient-depleted layer (NDL) and the euphotic zone. The amount of POC export flux at the NDL base suggests that the NDL could be a hotspot of particle export. The substantial POC export flux at the NDL base challenges traditional concepts that the NDL was limited in terms of POC export. The dominant nutrient source for POC export fluxes should be subsurface nutrients, which was determined by 15N isotopic mass balance.
Zhixuan Wang, Guizhi Wang, Xianghui Guo, Yan Bai, Yi Xu, and Minhan Dai
Earth Syst. Sci. Data, 15, 1711–1731, https://doi.org/10.5194/essd-15-1711-2023, https://doi.org/10.5194/essd-15-1711-2023, 2023
Short summary
Short summary
We reconstructed monthly sea surface pCO2 data with a high spatial resolution in the South China Sea (SCS) from 2003 to 2020. We validate our reconstruction with three independent testing datasets and present a new method to assess the uncertainty of the data. The results strongly suggest that our reconstruction effectively captures the main features of the spatiotemporal patterns of pCO2 in the SCS. Using this dataset, we found that the SCS is overall a weak source of atmospheric CO2.
Yangyang Zhao, Khanittha Uthaipan, Zhongming Lu, Yan Li, Jing Liu, Hongbin Liu, Jianping Gan, Feifei Meng, and Minhan Dai
Biogeosciences, 18, 2755–2775, https://doi.org/10.5194/bg-18-2755-2021, https://doi.org/10.5194/bg-18-2755-2021, 2021
Short summary
Short summary
In situ oxygen consumption rates were estimated for the first time during destruction of coastal hypoxia as disturbed by a typhoon and its reinstatement in the South China Sea off the Pearl River estuary. The reinstatement of summer hypoxia was rapid with a comparable timescale with that of its initial disturbance from frequent tropical cyclones, which has important implications for better understanding the intermittent nature of coastal hypoxia and its prediction in a changing climate.
Guizhi Wang, Samuel S. P. Shen, Yao Chen, Yan Bai, Huan Qin, Zhixuan Wang, Baoshan Chen, Xianghui Guo, and Minhan Dai
Earth Syst. Sci. Data, 13, 1403–1417, https://doi.org/10.5194/essd-13-1403-2021, https://doi.org/10.5194/essd-13-1403-2021, 2021
Short summary
Short summary
This study reconstructs a complete field of summer sea surface partial pressure of CO2 (pCO2) over the South China Sea (SCS) with a 0.5° resolution in the period of 2000–2017 using the scattered underway pCO2 observations. The spectral optimal gridding method was used in this reconstruction with empirical orthogonal functions computed from remote sensing data. Our reconstructed data show that the rate of sea surface pCO2 increase in the SCS is 2.4 ± 0.8 µatm yr-1 during 2000–2017.
Yanhong Lu, Shunyan Cheung, Ling Chen, Shuh-Ji Kao, Xiaomin Xia, Jianping Gan, Minhan Dai, and Hongbin Liu
Biogeosciences, 17, 6017–6032, https://doi.org/10.5194/bg-17-6017-2020, https://doi.org/10.5194/bg-17-6017-2020, 2020
Short summary
Short summary
Through a comprehensive investigation, we observed differential niche partitioning among diverse ammonia-oxidizing archaea (AOA) sublineages in a typical subtropical estuary. Distinct AOA communities observed at DNA and RNA levels suggested that a strong divergence in ammonia-oxidizing activity among different AOA groups occurs. Our result highlights the importance of identifying major ammonia oxidizers at RNA level in future studies.
Li Ma, Hua Lin, Xiabing Xie, Minhan Dai, and Yao Zhang
Biogeosciences, 16, 4765–4781, https://doi.org/10.5194/bg-16-4765-2019, https://doi.org/10.5194/bg-16-4765-2019, 2019
Short summary
Short summary
The major microbial process producing N2O in estuarine ecosystems remains controversial. Combining the concentrations and isotopic compositions of N2O, distributions and transcript levels of ammonia-oxidizing bacterial and archaeal amoA and denitrifier nirS genes, and in situ incubation estimates of nitrification rates and N2O production rates, we clarified that ammonia-oxidizing bacteria contributed the major part in N2O production in the upper Pearl River estuary despite their low abundance.
Xin Lin, Ruiping Huang, Yan Li, Futian Li, Yaping Wu, David A. Hutchins, Minhan Dai, and Kunshan Gao
Biogeosciences, 15, 551–565, https://doi.org/10.5194/bg-15-551-2018, https://doi.org/10.5194/bg-15-551-2018, 2018
Short summary
Short summary
We examine the effects of elevated CO2 on bacterioplankton community during a mesocosm experiment in subtropical, eutrophic coastal waters in southern China. We found that the elevated CO2 hardly altered the network structure of the bacterioplankton taxa present with high abundance but appeared to reassemble the community network of taxa with low abundance. Results suggest that the bacterioplankton community in this subtropical, high-nutrient coastal environment is insensitive to elevated CO2.
Jianzhong Su, Minhan Dai, Biyan He, Lifang Wang, Jianping Gan, Xianghui Guo, Huade Zhao, and Fengling Yu
Biogeosciences, 14, 4085–4099, https://doi.org/10.5194/bg-14-4085-2017, https://doi.org/10.5194/bg-14-4085-2017, 2017
Short summary
Short summary
We provide direct and quantitative assessments showing the marine organic matter from eutrophication-induced primary production dominated oxygen consumption in the hypoxic zone, while the terrestrially sourced organic matter also significantly contributed to the formation and maintenance of hypoxia in the lower Pearl River Estuary (PRE) and the adjacent coastal water.
Xiaobo Jin, Chuanlian Liu, Alex J. Poulton, Minhan Dai, and Xianghui Guo
Biogeosciences, 13, 4843–4861, https://doi.org/10.5194/bg-13-4843-2016, https://doi.org/10.5194/bg-13-4843-2016, 2016
Short summary
Short summary
The vertical structure of the coccolithophore community in the water column was controlled by trophic conditions, which were regulated by mesoscale eddies across the South China Sea basin. Three key species (Emiliania huxleyi, Gephyrocapsa oceanica, Florisphaera profunda) contributed roughly half of the surface ocean coccolith-calcite concentrations. E. huxleyi coccolith length is influenced by light and nutrients through the regulation of growth rates.
Shuh-Ji Kao, Tzu-Ling Chiang, Da-Wei Li, Yi-Chia Hsin, Li-Wei Zheng, Jin-Yu Terence Yang, Shih-Chieh Hsu, Chau-Ron Wu, and Minhan Dai
Clim. Past Discuss., https://doi.org/10.5194/cp-2015-167, https://doi.org/10.5194/cp-2015-167, 2016
Preprint withdrawn
Short summary
Short summary
A 3-D model was run for the South China Sea to explore the effects of sea level drop and monsoon wind intensity on glacial patterns of circulation and ventilation. Winter northeasterly monsoon wind intensity governs the volume transport of Kuroshio intrusion through the Luzon Strait, subsequently, the water exchange rate and the mean residence time of water body of the SCS.
X.-H. Guo, W.-D. Zhai, M.-H. Dai, C. Zhang, Y. Bai, Y. Xu, Q. Li, and G.-Z. Wang
Biogeosciences, 12, 5495–5514, https://doi.org/10.5194/bg-12-5495-2015, https://doi.org/10.5194/bg-12-5495-2015, 2015
Short summary
Short summary
We report the most comprehensive data set of surface seawater pCO2 and air-sea CO2 fluxes in the East China Sea (ECS) based on 24 surveys conducted in 2006-2011. We categorized the ECS into five different domains characterized by different physics and biogeochemistry to better characterize the seasonality of the pCO2 dynamics and to better constrain the CO2 flux. The annual average CO2 influx into the entire ECS shelf was 6.9+/-4.0 mmol m-2 d-1, about twice the global average in an ocean margin.
Z. Cao, M. Dai, W. Evans, J. Gan, and R. Feely
Biogeosciences, 11, 6341–6354, https://doi.org/10.5194/bg-11-6341-2014, https://doi.org/10.5194/bg-11-6341-2014, 2014
N. Jiao, Y. Zhang, K. Zhou, Q. Li, M. Dai, J. Liu, J. Guo, and B. Huang
Biogeosciences, 11, 2465–2475, https://doi.org/10.5194/bg-11-2465-2014, https://doi.org/10.5194/bg-11-2465-2014, 2014
S. S.-Y. Hsiao, T.-C. Hsu, J.-w. Liu, X. Xie, Y. Zhang, J. Lin, H. Wang, J.-Y. T. Yang, S.-C. Hsu, M. Dai, and S.-J. Kao
Biogeosciences, 11, 2083–2098, https://doi.org/10.5194/bg-11-2083-2014, https://doi.org/10.5194/bg-11-2083-2014, 2014
J.-Y. T. Yang, S.-C. Hsu, M. H. Dai, S. S.-Y. Hsiao, and S.-J. Kao
Biogeosciences, 11, 1833–1846, https://doi.org/10.5194/bg-11-1833-2014, https://doi.org/10.5194/bg-11-1833-2014, 2014
S.-J. Kao, R. G. Hilton, K. Selvaraj, M. Dai, F. Zehetner, J.-C. Huang, S.-C. Hsu, R. Sparkes, J. T. Liu, T.-Y. Lee, J.-Y. T. Yang, A. Galy, X. Xu, and N. Hovius
Earth Surf. Dynam., 2, 127–139, https://doi.org/10.5194/esurf-2-127-2014, https://doi.org/10.5194/esurf-2-127-2014, 2014
Y.-F. Tseng, J. Lin, M. Dai, and S.-J. Kao
Biogeosciences, 11, 409–423, https://doi.org/10.5194/bg-11-409-2014, https://doi.org/10.5194/bg-11-409-2014, 2014
A. Q. Han, M. H. Dai, J. P. Gan, S.-J. Kao, X. Z. Zhao, S. Jan, Q. Li, H. Lin, C.-T. A. Chen, L. Wang, J. Y. Hu, L. F. Wang, and F. Gong
Biogeosciences, 10, 8159–8170, https://doi.org/10.5194/bg-10-8159-2013, https://doi.org/10.5194/bg-10-8159-2013, 2013
W.-D. Zhai, M.-H. Dai, B.-S. Chen, X.-H. Guo, Q. Li, S.-L. Shang, C.-Y. Zhang, W.-J. Cai, and D.-X. Wang
Biogeosciences, 10, 7775–7791, https://doi.org/10.5194/bg-10-7775-2013, https://doi.org/10.5194/bg-10-7775-2013, 2013
K.-K. Liu, L.-W. Wang, M. Dai, C.-M. Tseng, Y. Yang, C.-H. Sui, L. Oey, K.-Y. Tseng, and S.-M. Huang
Biogeosciences, 10, 7449–7462, https://doi.org/10.5194/bg-10-7449-2013, https://doi.org/10.5194/bg-10-7449-2013, 2013
C. Du, Z. Liu, M. Dai, S.-J. Kao, Z. Cao, Y. Zhang, T. Huang, L. Wang, and Y. Li
Biogeosciences, 10, 6419–6432, https://doi.org/10.5194/bg-10-6419-2013, https://doi.org/10.5194/bg-10-6419-2013, 2013
Related subject area
Biogeochemistry: Coastal Ocean
Long-term variations in pH in coastal waters along the Korean Peninsula
The effect of carbonate mineral additions on biogeochemical conditions in surface sediments and benthic–pelagic exchange fluxes
Assessing the impacts of simulated ocean alkalinity enhancement on viability and growth of nearshore species of phytoplankton
Responses of microbial metabolic rates to non-equilibrated silicate- versus calcium-based ocean alkalinity enhancement
High metabolic zinc demand within native Amundsen and Ross sea phytoplankton communities determined by stable isotope uptake rate measurements
The influence of zooplankton and oxygen on the particulate organic carbon flux in the Benguela Upwelling System
Reviews and syntheses: Biological indicators of low-oxygen stress in marine water-breathing animals
Temperature-enhanced effects of iron on Southern Ocean phytoplankton
Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth system model
Effects of Submarine Groundwater on Nutrient Concentration and Primary Production in a Deep Bay of the Japan Sea
The Northeast Greenland Shelf as a potential late-summer CO2 source to the atmosphere
Technical note: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project (OAEPIIP)
Estimates of carbon sequestration potential in an expanding Arctic fjord (Hornsund, Svalbard) affected by dark plumes of glacial meltwater
An assessment of ocean alkalinity enhancement using aqueous hydroxides: kinetics, efficiency, and precipitation thresholds
Dissolved nitric oxide in the lower Elbe Estuary and the Port of Hamburg area
The bacteria-protist link as a main route of dissolved organic matter across contrasting productivity areas in the Patagonian Shelf
Technical note: New approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer on voluntary observing ships
Variable contribution of wastewater treatment plant effluents to downstream nitrous oxide concentrations and emissions
Distribution of nutrients and dissolved organic matter in a eutrophic equatorial estuary: the Johor River and the East Johor Strait
Investigating the effect of silicate- and calcium-based ocean alkalinity enhancement on diatom silicification
Ocean alkalinity enhancement using sodium carbonate salts does not lead to measurable changes in Fe dynamics in a mesocosm experiment
Quantification and mitigation of bottom-trawling impacts on sedimentary organic carbon stocks in the North Sea
Influence of ocean alkalinity enhancement with olivine or steel slag on a coastal plankton community in Tasmania
Reviews and synthesis: increasing hypoxia in eastern boundary upwelling systems: a major stressor for zooplankton
Multi-model comparison of trends and controls of near-bed oxygen concentration on the northwest European continental shelf under climate change
Picoplanktonic methane production in eutrophic surface waters
Vertical mixing alleviates autumnal oxygen deficiency in the central North Sea
Hypoxia also occurs in small highly turbid estuaries: the example of the Charente (Bay of Biscay)
Seasonality and response of ocean acidification and hypoxia to major environmental anomalies in the southern Salish Sea, North America (2014–2018)
Ocean Alkalinity Enhancement (OAE) does not cause cellular stress in a phytoplankton community of the sub-tropical Atlantic Ocean
Oceanographic processes driving low-oxygen conditions inside Patagonian fjords
Above- and belowground plant mercury dynamics in a salt marsh estuary in Massachusetts, USA
Variability and drivers of carbonate chemistry at shellfish aquaculture sites in the Salish Sea, British Columbia
Unusual Hemiaulus bloom influences ocean productivity in Northeastern US Shelf waters
Insights into carbonate environmental conditions in the Chukchi Sea
UAV approaches for improved mapping of vegetation cover and estimation of carbon storage of small saltmarshes: examples from Loch Fleet, northeast Scotland
Iron “ore” nothing: benthic iron fluxes from the oxygen-deficient Santa Barbara Basin enhance phytoplankton productivity in surface waters
Marine anoxia initiates giant sulfur-oxidizing bacterial mat proliferation and associated changes in benthic nitrogen, sulfur, and iron cycling in the Santa Barbara Basin, California Borderland
Uncertainty in the evolution of northwestern North Atlantic circulation leads to diverging biogeochemical projections
The additionality problem of ocean alkalinity enhancement
Short-term variation in pH in seawaters around coastal areas of Japan: characteristics and forcings
Revisiting the applicability and constraints of molybdenum- and uranium-based paleo redox proxies: comparing two contrasting sill fjords
Influence of a small submarine canyon on biogenic matter export flux in the lower St. Lawrence Estuary, eastern Canada
Single-celled bioturbators: benthic foraminifera mediate oxygen penetration and prokaryotic diversity in intertidal sediment
Assessing impacts of coastal warming, acidification, and deoxygenation on Pacific oyster (Crassostrea gigas) farming: a case study in the Hinase area, Okayama Prefecture, and Shizugawa Bay, Miyagi Prefecture, Japan
Multiple nitrogen sources for primary production inferred from δ13C and δ15N in the southern Sea of Japan
Influence of manganese cycling on alkalinity in the redox stratified water column of Chesapeake Bay
Estuarine flocculation dynamics of organic carbon and metals from boreal acid sulfate soils
Drivers of particle sinking velocities in the Peruvian upwelling system
Impacts and uncertainties of climate-induced changes in watershed inputs on estuarine hypoxia
Yong-Woo Lee, Mi-Ok Park, Seong-Gil Kim, Tae-Hoon Kim, Yong Hwa Oh, Sang Heon Lee, and DongJoo Joung
Biogeosciences, 22, 675–690, https://doi.org/10.5194/bg-22-675-2025, https://doi.org/10.5194/bg-22-675-2025, 2025
Short summary
Short summary
Long-term pH variation in coastal waters along the Korean Peninsula was assessed for the first time, and it exhibited no significant pH change over an 11-year period. This contrasts with the ongoing pH decline in open oceans and other coastal areas. Analysis of environmental data showed that pH is mainly controlled by dissolved oxygen in bottom waters. This suggests that ocean warming could cause a pH decline in Korean coastal waters, affecting many fish and seaweed aquaculture operations.
Kadir Biçe, Tristen Myers Stewart, George G. Waldbusser, and Christof Meile
Biogeosciences, 22, 641–657, https://doi.org/10.5194/bg-22-641-2025, https://doi.org/10.5194/bg-22-641-2025, 2025
Short summary
Short summary
We studied the effect of addition of carbonate minerals on coastal sediments. We carried out laboratory experiments to quantify the dissolution kinetics and integrated these observations into a numerical model that describes biogeochemical cycling in surficial sediments. Using the model, we demonstrate the buffering effect of the mineral additions and their duration. We quantify the effect under different environmental conditions and assess the potential for increased atmospheric CO2 uptake.
Jessica L. Oberlander, Mackenzie E. Burke, Cat A. London, and Hugh L. MacIntyre
Biogeosciences, 22, 499–512, https://doi.org/10.5194/bg-22-499-2025, https://doi.org/10.5194/bg-22-499-2025, 2025
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a promising negative emission technology that results in the net sequestration of atmospheric carbon. In this paper, we assess the potential impact of OAE on phytoplankton through an analysis of prior studies and the effects of simulated OAE on photosynthetic competence. Our findings suggest that there may be little if any significant impact on most phytoplankton studied to date if OAE is conducted in well-flushed, nearshore environments.
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, and Ulf Riebesell
Biogeosciences, 21, 5707–5724, https://doi.org/10.5194/bg-21-5707-2024, https://doi.org/10.5194/bg-21-5707-2024, 2024
Short summary
Short summary
This study exposed a natural community to two non-CO2-equilibrated ocean alkalinity enhancement (OAE) deployments using different minerals. Adding alkalinity in this manner decreases dissolved CO2, essential for photosynthesis. While photosynthesis was not suppressed, bloom formation was mildly delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and on its ecological implications.
Riss M. Kell, Rebecca J. Chmiel, Deepa Rao, Dawn M. Moran, Matthew R. McIlvin, Tristan J. Horner, Nicole L. Schanke, Ichiko Sugiyama, Robert B. Dunbar, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 21, 5685–5706, https://doi.org/10.5194/bg-21-5685-2024, https://doi.org/10.5194/bg-21-5685-2024, 2024
Short summary
Short summary
Despite interest in modeling the biogeochemical uptake and cycling of the trace metal zinc (Zn), measurements of Zn uptake in natural marine phytoplankton communities have not been conducted previously. To fill this gap, we employed a stable isotope uptake rate measurement method to quantify Zn uptake into natural phytoplankton assemblages within the Southern Ocean. Zn demand was high and rapid enough to depress the inventory of Zn available to phytoplankton on seasonal timescales.
Luisa Chiara Meiritz, Tim Rixen, Anja Karin van der Plas, Tarron Lamont, and Niko Lahajnar
Biogeosciences, 21, 5261–5276, https://doi.org/10.5194/bg-21-5261-2024, https://doi.org/10.5194/bg-21-5261-2024, 2024
Short summary
Short summary
Moored and drifting sediment trap experiments in the northern (nBUS) and southern (sBUS) Benguela Upwelling System showed that active carbon fluxes by vertically migrating zooplankton were about 3 times higher in the sBUS than in the nBUS. Despite these large variabilities, the mean passive particulate organic carbon (POC) fluxes were almost equal in the two subsystems. The more intense near-bottom oxygen minimum layer seems to lead to higher POC fluxes and accumulation rates in the nBUS.
Michael R. Roman, Andrew H. Altieri, Denise Breitburg, Erica M. Ferrer, Natalya D. Gallo, Shin-ichi Ito, Karin Limburg, Kenneth Rose, Moriaki Yasuhara, and Lisa A. Levin
Biogeosciences, 21, 4975–5004, https://doi.org/10.5194/bg-21-4975-2024, https://doi.org/10.5194/bg-21-4975-2024, 2024
Short summary
Short summary
Oxygen-depleted ocean waters have increased worldwide. In order to improve our understanding of the impacts of this oxygen loss on marine life it is essential that we develop reliable indicators that track the negative impacts of low oxygen. We review various indicators of low-oxygen stress for marine animals including their use, research needs, and application to confront the challenges of ocean oxygen loss.
Charlotte Eich, Mathijs van Manen, J. Scott P. McCain, Loay J. Jabre, Willem H. van de Poll, Jinyoung Jung, Sven B. E. H. Pont, Hung-An Tian, Indah Ardiningsih, Gert-Jan Reichart, Erin M. Bertrand, Corina P. D. Brussaard, and Rob Middag
Biogeosciences, 21, 4637–4663, https://doi.org/10.5194/bg-21-4637-2024, https://doi.org/10.5194/bg-21-4637-2024, 2024
Short summary
Short summary
Phytoplankton growth in the Southern Ocean (SO) is often limited by low iron (Fe) concentrations. Sea surface warming impacts Fe availability and can affect phytoplankton growth. We used shipboard Fe clean incubations to test how changes in Fe and temperature affect SO phytoplankton. Their abundances usually increased with Fe addition and temperature increase, with Fe being the major factor. These findings imply potential shifts in ecosystem structure, impacting food webs and elemental cycling.
Miriam Tivig, David P. Keller, and Andreas Oschlies
Biogeosciences, 21, 4469–4493, https://doi.org/10.5194/bg-21-4469-2024, https://doi.org/10.5194/bg-21-4469-2024, 2024
Short summary
Short summary
Marine biological production is highly dependent on the availability of nitrogen and phosphorus. Rivers are the main source of phosphorus to the oceans but poorly represented in global model oceans. We include dissolved nitrogen and phosphorus from river export in a global model ocean and find that the addition of riverine phosphorus affects marine biology on millennial timescales more than riverine nitrogen alone. Globally, riverine phosphorus input increases primary production rates.
Menghong Dong, Xinyu Guo, Takuya Matsuura, Taichi Tebakari, and Jing Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2581, https://doi.org/10.5194/egusphere-2024-2581, 2024
Short summary
Short summary
Submarine groundwater discharge (SGD), a common coastal hydrological process that involves submarine inflow of groundwater into the sea, is associated with a large nutrient load. To clarify the distribution of SGD-derived nutrients after release at the bottom of the sea and their contribution to phytoplankton growth in the marine ecosystem, we modeled the SGD process in Toyama Bay using a specialized computer code that can distinguish SGD-derived nutrients from nutrients from other sources.
Esdoorn Willcox, Marcos Lemes, Thomas Juul-Pedersen, Mikael Kristian Sejr, Johnna Marchiano Holding, and Søren Rysgaard
Biogeosciences, 21, 4037–4050, https://doi.org/10.5194/bg-21-4037-2024, https://doi.org/10.5194/bg-21-4037-2024, 2024
Short summary
Short summary
In this work, we measured the chemistry of seawater from samples obtained from different depths and locations off the east coast of the Northeast Greenland National Park to determine what is influencing concentrations of dissolved CO2. Historically, the region has always been thought to take up CO2 from the atmosphere, but we show that it is possible for the region to become a source in late summer. We discuss the variables that may be related to such changes.
Lennart Thomas Bach, Aaron James Ferderer, Julie LaRoche, and Kai Georg Schulz
Biogeosciences, 21, 3665–3676, https://doi.org/10.5194/bg-21-3665-2024, https://doi.org/10.5194/bg-21-3665-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is an emerging marine CO2 removal method, but its environmental effects are insufficiently understood. The OAE Pelagic Impact Intercomparison Project (OAEPIIP) provides funding for a standardized and globally replicated microcosm experiment to study the effects of OAE on plankton communities. Here, we provide a detailed manual for the OAEPIIP experiment. We expect OAEPIIP to help build scientific consensus on the effects of OAE on plankton.
Marlena Szeligowska, Déborah Benkort, Anna Przyborska, Mateusz Moskalik, Bernabé Moreno, Emilia Trudnowska, and Katarzyna Błachowiak-Samołyk
Biogeosciences, 21, 3617–3639, https://doi.org/10.5194/bg-21-3617-2024, https://doi.org/10.5194/bg-21-3617-2024, 2024
Short summary
Short summary
The European Arctic is experiencing rapid regional warming, causing glaciers that terminate in the sea to retreat onto land. Due to this process, the area of a well-studied fjord, Hornsund, has increased by around 100 km2 (40%) since 1976. Combining satellite and in situ data with a mathematical model, we estimated that, despite some negative consequences of glacial meltwater release, such emerging coastal waters could mitigate climate change by increasing carbon uptake and storage by sediments.
Mallory C. Ringham, Nathan Hirtle, Cody Shaw, Xi Lu, Julian Herndon, Brendan R. Carter, and Matthew D. Eisaman
Biogeosciences, 21, 3551–3570, https://doi.org/10.5194/bg-21-3551-2024, https://doi.org/10.5194/bg-21-3551-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement leverages the large surface area and carbon storage capacity of the oceans to store atmospheric CO2 as dissolved bicarbonate. We monitored CO2 uptake in seawater treated with NaOH to establish operational boundaries for carbon removal experiments. Results show that CO2 equilibration occurred on the order of weeks to months, was consistent with values expected from equilibration calculations, and was limited by mineral precipitation at high pH and CaCO3 saturation.
Riel Carlo O. Ingeniero, Gesa Schulz, and Hermann W. Bange
Biogeosciences, 21, 3425–3440, https://doi.org/10.5194/bg-21-3425-2024, https://doi.org/10.5194/bg-21-3425-2024, 2024
Short summary
Short summary
Our research is the first to measure dissolved NO concentrations in temperate estuarine waters, providing insights into its distribution under varying conditions and enhancing our understanding of its production processes. Dissolved NO was supersaturated in the Elbe Estuary, indicating that it is a source of atmospheric NO. The observed distribution of dissolved NO most likely resulted from nitrification.
Celeste López-Abbate, John E. Garzón-Cardona, Ricardo Silva, Juan-Carlos Molinero, Laura A. Ruiz-Etcheverry, Ana M. Martínez, Azul S. Gilabert, and Rubén J. Lara
EGUsphere, https://doi.org/10.5194/egusphere-2024-1860, https://doi.org/10.5194/egusphere-2024-1860, 2024
Short summary
Short summary
This study examines how microbial community structure, growth, and grazing impact the DOM pool in the Patagonian Shelf. Despite higher phytoplankton biomass, faster-growing bacteria were selectively grazed by protists leading to DOM accumulation, likely due to a reduction in DOM-consuming bacteria and the addition of egestion compounds. Experimental data showed that while bacteria remained as the primarily shapers of DOM quality, grazing pressure impacted on DOM accumulation.
Sören Iwe, Oliver Schmale, and Bernd Schneider
EGUsphere, https://doi.org/10.5194/egusphere-2024-2049, https://doi.org/10.5194/egusphere-2024-2049, 2024
Short summary
Short summary
We present a novel method to quantify N2 fixation by cyanobacteria, crucial in Baltic Sea eutrophication. Our Gas Equilibrium – Membrane-Inlet Mass Spectrometer (GE-MIMS), designed for operation on voluntary observing ships (VOS), enables large-scale monitoring of surface water N2 depletion caused by N2 fixation. Laboratory tests confirm the device’s accuracy and precision, ensuring it can complement current methods and contribute valuable data to better understand N2 fixation in the Baltic Sea.
Weiyi Tang, Jeff Talbott, Timothy Jones, and Bess B. Ward
Biogeosciences, 21, 3239–3250, https://doi.org/10.5194/bg-21-3239-2024, https://doi.org/10.5194/bg-21-3239-2024, 2024
Short summary
Short summary
Wastewater treatment plants (WWTPs) are known to be hotspots of greenhouse gas emissions. However, the impact of WWTPs on the emission of the greenhouse gas N2O in downstream aquatic environments is less constrained. We found spatially and temporally variable but overall higher N2O concentrations and fluxes in waters downstream of WWTPs, pointing to the need for efficient N2O removal in addition to the treatment of nitrogen in WWTPs.
Amanda Y. L. Cheong, Kogila Vani Annammala, Ee Ling Yong, Yongli Zhou, Robert S. Nichols, and Patrick Martin
Biogeosciences, 21, 2955–2971, https://doi.org/10.5194/bg-21-2955-2024, https://doi.org/10.5194/bg-21-2955-2024, 2024
Short summary
Short summary
We measured nutrients and dissolved organic matter for 1 year in a eutrophic tropical estuary to understand their sources and cycling. Our data show that the dissolved organic matter originates partly from land and partly from microbial processes in the water. Internal recycling is likely important for maintaining high nutrient concentrations, and we found that there is often excess nitrogen compared to silicon and phosphorus. Our data help to explain how eutrophication persists in this system.
Aaron Ferderer, Kai G. Schulz, Ulf Riebesell, Kirralee G. Baker, Zanna Chase, and Lennart T. Bach
Biogeosciences, 21, 2777–2794, https://doi.org/10.5194/bg-21-2777-2024, https://doi.org/10.5194/bg-21-2777-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a promising method of atmospheric carbon removal; however, its ecological impacts remain largely unknown. We assessed the effects of simulated silicate- and calcium-based mineral OAE on diatom silicification. We found that increased silicate concentrations from silicate-based OAE increased diatom silicification. In contrast, the enhancement of alkalinity had no effect on community silicification and minimal effects on the silicification of different genera.
David González-Santana, María Segovia, Melchor González-Dávila, Librada Ramírez, Aridane G. González, Leonardo J. Pozzo-Pirotta, Veronica Arnone, Victor Vázquez, Ulf Riebesell, and J. Magdalena Santana-Casiano
Biogeosciences, 21, 2705–2715, https://doi.org/10.5194/bg-21-2705-2024, https://doi.org/10.5194/bg-21-2705-2024, 2024
Short summary
Short summary
In a recent experiment off the coast of Gran Canaria (Spain), scientists explored a method called ocean alkalinization enhancement (OAE), where carbonate minerals were added to seawater. This process changed the levels of certain ions in the water, affecting its pH and buffering capacity. The researchers were particularly interested in how this could impact the levels of essential trace metals in the water.
Lucas Porz, Wenyan Zhang, Nils Christiansen, Jan Kossack, Ute Daewel, and Corinna Schrum
Biogeosciences, 21, 2547–2570, https://doi.org/10.5194/bg-21-2547-2024, https://doi.org/10.5194/bg-21-2547-2024, 2024
Short summary
Short summary
Seafloor sediments store a large amount of carbon, helping to naturally regulate Earth's climate. If disturbed, some sediment particles can turn into CO2, but this effect is not well understood. Using computer simulations, we found that bottom-contacting fishing gears release about 1 million tons of CO2 per year in the North Sea, one of the most heavily fished regions globally. We show how protecting certain areas could reduce these emissions while also benefitting seafloor-living animals.
Jiaying A. Guo, Robert F. Strzepek, Kerrie M. Swadling, Ashley T. Townsend, and Lennart T. Bach
Biogeosciences, 21, 2335–2354, https://doi.org/10.5194/bg-21-2335-2024, https://doi.org/10.5194/bg-21-2335-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement aims to increase atmospheric CO2 sequestration by adding alkaline materials to the ocean. We assessed the environmental effects of olivine and steel slag powder on coastal plankton. Overall, slag is more efficient than olivine in releasing total alkalinity and, thus, in its ability to sequester CO2. Slag also had less environmental effect on the enclosed plankton communities when considering its higher CO2 removal potential based on this 3-week experiment.
Leissing Frederick, Mauricio A. Urbina, and Ruben Escribano
EGUsphere, https://doi.org/10.5194/egusphere-2024-836, https://doi.org/10.5194/egusphere-2024-836, 2024
Short summary
Short summary
Evidence shows that due to global warming zooplankton inhabiting the coastal upwelling zone are exposed to increasing hypoxia affecting their physiology, metabolism, and population dynamics. The adaptive responses of zooplankton to cope with mild/severe hypoxia may depend on trade-offs with other metabolic/energy-demands, implying less energy for growth, feeding and reproduction with ecological consequences for the zooplankton populations and the marine food web.
Giovanni Galli, Sarah Wakelin, James Harle, Jason Holt, and Yuri Artioli
Biogeosciences, 21, 2143–2158, https://doi.org/10.5194/bg-21-2143-2024, https://doi.org/10.5194/bg-21-2143-2024, 2024
Short summary
Short summary
This work shows that, under a high-emission scenario, oxygen concentration in deep water of parts of the North Sea and Celtic Sea can become critically low (hypoxia) towards the end of this century. The extent and frequency of hypoxia depends on the intensity of climate change projected by different climate models. This is the result of a complex combination of factors like warming, increase in stratification, changes in the currents and changes in biological processes.
Sandy E. Tenorio and Laura Farías
Biogeosciences, 21, 2029–2050, https://doi.org/10.5194/bg-21-2029-2024, https://doi.org/10.5194/bg-21-2029-2024, 2024
Short summary
Short summary
Time series studies show that CH4 is highly dynamic on the coastal ocean surface and planktonic communities are linked to CH4 accumulation, as found in coastal upwelling off Chile. We have identified the crucial role of picoplankton (> 3 µm) in CH4 recycling, especially with the addition of methylated substrates (trimethylamine and methylphosphonic acid) during upwelling and non-upwelling periods. These insights improve understanding of surface ocean CH4 recycling, aiding CH4 emission estimates.
Charlotte A. J. Williams, Tom Hull, Jan Kaiser, Claire Mahaffey, Naomi Greenwood, Matthew Toberman, and Matthew R. Palmer
Biogeosciences, 21, 1961–1971, https://doi.org/10.5194/bg-21-1961-2024, https://doi.org/10.5194/bg-21-1961-2024, 2024
Short summary
Short summary
Oxygen (O2) is a key indicator of ocean health. The risk of O2 loss in the productive coastal/continental slope regions is increasing. Autonomous underwater vehicles equipped with O2 optodes provide lots of data but have problems resolving strong vertical O2 changes. Here we show how to overcome this and calculate how much O2 is supplied to the low-O2 bottom waters via mixing. Bursts in mixing supply nearly all of the O2 to bottom waters in autumn, stopping them reaching ecologically low levels.
Sabine Schmidt and Ibrahima Iris Diallo
Biogeosciences, 21, 1785–1800, https://doi.org/10.5194/bg-21-1785-2024, https://doi.org/10.5194/bg-21-1785-2024, 2024
Short summary
Short summary
Along the French coast facing the Bay of Biscay, the large Gironde and Loire estuaries suffer from hypoxia. This prompted a study of the small Charente estuary located between them. This work reveals a minimum oxygen zone in the Charente estuary, which extends for about 25 km. Temperature is the main factor controlling the hypoxia. This calls for the monitoring of small turbid macrotidal estuaries that are vulnerable to hypoxia, a risk expected to increase with global warming.
Simone R. Alin, Jan A. Newton, Richard A. Feely, Samantha Siedlecki, and Dana Greeley
Biogeosciences, 21, 1639–1673, https://doi.org/10.5194/bg-21-1639-2024, https://doi.org/10.5194/bg-21-1639-2024, 2024
Short summary
Short summary
We provide a new multi-stressor data product that allows us to characterize the seasonality of temperature, O2, and CO2 in the southern Salish Sea and delivers insights into the impacts of major marine heatwave and precipitation anomalies on regional ocean acidification and hypoxia. We also describe the present-day frequencies of temperature, O2, and ocean acidification conditions that cross thresholds of sensitive regional species that are economically or ecologically important.
Librada Ramírez, Leonardo J. Pozzo-Pirotta, Aja Trebec, Víctor Manzanares-Vázquez, José L. Díez, Javier Arístegui, Ulf Riebesell, Stephen D. Archer, and María Segovia
EGUsphere, https://doi.org/10.5194/egusphere-2024-847, https://doi.org/10.5194/egusphere-2024-847, 2024
Short summary
Short summary
We studied the potential effects of increasing ocean alkalinity on a natural plankton community in subtropical waters of the Atlantic near Gran Canaria, Spain. Alkalinity is the capacity of water to resist acidification and plankton are usually microscopic plants (phytoplankton) and animals (zooplankton), often less than 2,5 cm in length. This study suggests that increasing ocean alkalinity did not have a significant negative impact on the studied plankton community.
Pamela Linford, Iván Pérez-Santos, Paulina Montero, Patricio A. Díaz, Claudia Aracena, Elías Pinilla, Facundo Barrera, Manuel Castillo, Aida Alvera-Azcárate, Mónica Alvarado, Gabriel Soto, Cécile Pujol, Camila Schwerter, Sara Arenas-Uribe, Pilar Navarro, Guido Mancilla-Gutiérrez, Robinson Altamirano, Javiera San Martín, and Camila Soto-Riquelme
Biogeosciences, 21, 1433–1459, https://doi.org/10.5194/bg-21-1433-2024, https://doi.org/10.5194/bg-21-1433-2024, 2024
Short summary
Short summary
The Patagonian fjords comprise a world region where low-oxygen water and hypoxia conditions are observed. An in situ dataset was used to quantify the mechanism involved in the presence of these conditions in northern Patagonian fjords. Water mass analysis confirmed the contribution of Equatorial Subsurface Water in the advection of the low-oxygen water, and hypoxic conditions occurred when the community respiration rate exceeded the gross primary production.
Ting Wang, Buyun Du, Inke Forbrich, Jun Zhou, Joshua Polen, Elsie M. Sunderland, Prentiss H. Balcom, Celia Chen, and Daniel Obrist
Biogeosciences, 21, 1461–1476, https://doi.org/10.5194/bg-21-1461-2024, https://doi.org/10.5194/bg-21-1461-2024, 2024
Short summary
Short summary
The strong seasonal increases of Hg in aboveground biomass during the growing season and the lack of changes observed after senescence in this salt marsh ecosystem suggest physiologically controlled Hg uptake pathways. The Hg sources found in marsh aboveground tissues originate from a mix of sources, unlike terrestrial ecosystems, where atmospheric GEM is the main source. Belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.
Eleanor Simpson, Debby Ianson, Karen E. Kohfeld, Ana C. Franco, Paul A. Covert, Marty Davelaar, and Yves Perreault
Biogeosciences, 21, 1323–1353, https://doi.org/10.5194/bg-21-1323-2024, https://doi.org/10.5194/bg-21-1323-2024, 2024
Short summary
Short summary
Shellfish aquaculture operates in nearshore areas where data on ocean acidification parameters are limited. We show daily and seasonal variability in pH and saturation states of calcium carbonate at nearshore aquaculture sites in British Columbia, Canada, and determine the contributing drivers of this variability. We find that nearshore locations have greater variability than open waters and that the uptake of carbon by phytoplankton is the major driver of pH and saturation state variability.
S. Alejandra Castillo Cieza, Rachel H. R. Stanley, Pierre Marrec, Diana N. Fontaine, E. Taylor Crockford, Dennis J. McGillicuddy Jr., Arshia Mehta, Susanne Menden-Deuer, Emily E. Peacock, Tatiana A. Rynearson, Zoe O. Sandwith, Weifeng Zhang, and Heidi M. Sosik
Biogeosciences, 21, 1235–1257, https://doi.org/10.5194/bg-21-1235-2024, https://doi.org/10.5194/bg-21-1235-2024, 2024
Short summary
Short summary
The coastal ocean in the northeastern USA provides many services, including fisheries and habitats for threatened species. In summer 2019, a bloom occurred of a large unusual phytoplankton, the diatom Hemiaulus, with nitrogen-fixing symbionts. This led to vast changes in productivity and grazing rates in the ecosystem. This work shows that the emergence of one species can have profound effects on ecosystem function. Such changes may become more prevalent as the ocean warms due to climate change.
Claudine Hauri, Brita Irving, Sam Dupont, Rémi Pagés, Donna D. W. Hauser, and Seth L. Danielson
Biogeosciences, 21, 1135–1159, https://doi.org/10.5194/bg-21-1135-2024, https://doi.org/10.5194/bg-21-1135-2024, 2024
Short summary
Short summary
Arctic marine ecosystems are highly susceptible to impacts of climate change and ocean acidification. We present pH and pCO2 time series (2016–2020) from the Chukchi Ecosystem Observatory and analyze the drivers of the current conditions to get a better understanding of how climate change and ocean acidification could affect the ecological niches of organisms.
William Hiles, Lucy C. Miller, Craig Smeaton, and William E. N. Austin
Biogeosciences, 21, 929–948, https://doi.org/10.5194/bg-21-929-2024, https://doi.org/10.5194/bg-21-929-2024, 2024
Short summary
Short summary
Saltmarsh soils may help to limit the rate of climate change by storing carbon. To understand their impacts, they must be accurately mapped. We use drone data to estimate the size of three saltmarshes in NE Scotland. We find that drone imagery, combined with tidal data, can reliably inform our understanding of saltmarsh size. When compared with previous work using vegetation communities, we find that our most reliable new estimates of stored carbon are 15–20 % smaller than previously estimated.
De'Marcus Robinson, Anh L. D. Pham, David J. Yousavich, Felix Janssen, Frank Wenzhöfer, Eleanor C. Arrington, Kelsey M. Gosselin, Marco Sandoval-Belmar, Matthew Mar, David L. Valentine, Daniele Bianchi, and Tina Treude
Biogeosciences, 21, 773–788, https://doi.org/10.5194/bg-21-773-2024, https://doi.org/10.5194/bg-21-773-2024, 2024
Short summary
Short summary
The present study suggests that high release of ferrous iron from the seafloor of the oxygen-deficient Santa Barabara Basin (California) supports surface primary productivity, creating positive feedback on seafloor iron release by enhancing low-oxygen conditions in the basin.
David J. Yousavich, De'Marcus Robinson, Xuefeng Peng, Sebastian J. E. Krause, Frank Wenzhöfer, Felix Janssen, Na Liu, Jonathan Tarn, Franklin Kinnaman, David L. Valentine, and Tina Treude
Biogeosciences, 21, 789–809, https://doi.org/10.5194/bg-21-789-2024, https://doi.org/10.5194/bg-21-789-2024, 2024
Short summary
Short summary
Declining oxygen (O2) concentrations in coastal oceans can threaten people’s ways of life and food supplies. Here, we investigate how mats of bacteria that proliferate on the seafloor of the Santa Barbara Basin sustain and potentially worsen these O2 depletion events through their unique chemoautotrophic metabolism. Our study shows how changes in seafloor microbiology and geochemistry brought on by declining O2 concentrations can help these mats grow as well as how that growth affects the basin.
Krysten Rutherford, Katja Fennel, Lina Garcia Suarez, and Jasmin G. John
Biogeosciences, 21, 301–314, https://doi.org/10.5194/bg-21-301-2024, https://doi.org/10.5194/bg-21-301-2024, 2024
Short summary
Short summary
We downscaled two mid-century (~2075) ocean model projections to a high-resolution regional ocean model of the northwest North Atlantic (NA) shelf. In one projection, the NA shelf break current practically disappears; in the other it remains almost unchanged. This leads to a wide range of possible future shelf properties. More accurate projections of coastal circulation features would narrow the range of possible outcomes of biogeochemical projections for shelf regions.
Lennart Thomas Bach
Biogeosciences, 21, 261–277, https://doi.org/10.5194/bg-21-261-2024, https://doi.org/10.5194/bg-21-261-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a widely considered marine carbon dioxide removal method. OAE aims to accelerate chemical rock weathering, which is a natural process that slowly sequesters atmospheric carbon dioxide. This study shows that the addition of anthropogenic alkalinity via OAE can reduce the natural release of alkalinity and, therefore, reduce the efficiency of OAE for climate mitigation. However, the additionality problem could be mitigated via a variety of activities.
Tsuneo Ono, Daisuke Muraoka, Masahiro Hayashi, Makiko Yorifuji, Akihiro Dazai, Shigeyuki Omoto, Takehiro Tanaka, Tomohiro Okamura, Goh Onitsuka, Kenji Sudo, Masahiko Fujii, Ryuji Hamanoue, and Masahide Wakita
Biogeosciences, 21, 177–199, https://doi.org/10.5194/bg-21-177-2024, https://doi.org/10.5194/bg-21-177-2024, 2024
Short summary
Short summary
We carried out parallel year-round observations of pH and related parameters in five stations around the Japan coast. It was found that short-term acidified situations with Omega_ar less than 1.5 occurred at four of five stations. Most of such short-term acidified events were related to the short-term low salinity event, and the extent of short-term pH drawdown at high freshwater input was positively correlated with the nutrient concentration of the main rivers that flow into the coastal area.
K. Mareike Paul, Martijn Hermans, Sami A. Jokinen, Inda Brinkmann, Helena L. Filipsson, and Tom Jilbert
Biogeosciences, 20, 5003–5028, https://doi.org/10.5194/bg-20-5003-2023, https://doi.org/10.5194/bg-20-5003-2023, 2023
Short summary
Short summary
Seawater naturally contains trace metals such as Mo and U, which accumulate under low oxygen conditions on the seafloor. Previous studies have used sediment Mo and U contents as an archive of changing oxygen concentrations in coastal waters. Here we show that in fjords the use of Mo and U for this purpose may be impaired by additional processes. Our findings have implications for the reliable use of Mo and U to reconstruct oxygen changes in fjords.
Hannah Sharpe, Michel Gosselin, Catherine Lalande, Alexandre Normandeau, Jean-Carlos Montero-Serrano, Khouloud Baccara, Daniel Bourgault, Owen Sherwood, and Audrey Limoges
Biogeosciences, 20, 4981–5001, https://doi.org/10.5194/bg-20-4981-2023, https://doi.org/10.5194/bg-20-4981-2023, 2023
Short summary
Short summary
We studied the impact of submarine canyon processes within the Pointe-des-Monts system on biogenic matter export and phytoplankton assemblages. Using data from three oceanographic moorings, we show that the canyon experienced two low-amplitude sediment remobilization events in 2020–2021 that led to enhanced particle fluxes in the deep-water column layer > 2.6 km offshore. Sinking phytoplankton fluxes were lower near the canyon compared to background values from the lower St. Lawrence Estuary.
Dewi Langlet, Florian Mermillod-Blondin, Noémie Deldicq, Arthur Bauville, Gwendoline Duong, Lara Konecny, Mylène Hugoni, Lionel Denis, and Vincent M. P. Bouchet
Biogeosciences, 20, 4875–4891, https://doi.org/10.5194/bg-20-4875-2023, https://doi.org/10.5194/bg-20-4875-2023, 2023
Short summary
Short summary
Benthic foraminifera are single-cell marine organisms which can move in the sediment column. They were previously reported to horizontally and vertically transport sediment particles, yet the impact of their motion on the dissolved fluxes remains unknown. Using microprofiling, we show here that foraminiferal burrow formation increases the oxygen penetration depth in the sediment, leading to a change in the structure of the prokaryotic community.
Masahiko Fujii, Ryuji Hamanoue, Lawrence Patrick Cases Bernardo, Tsuneo Ono, Akihiro Dazai, Shigeyuki Oomoto, Masahide Wakita, and Takehiro Tanaka
Biogeosciences, 20, 4527–4549, https://doi.org/10.5194/bg-20-4527-2023, https://doi.org/10.5194/bg-20-4527-2023, 2023
Short summary
Short summary
This is the first study of the current and future impacts of climate change on Pacific oyster farming in Japan. Future coastal warming and acidification may affect oyster larvae as a result of longer exposure to lower-pH waters. A prolonged spawning period may harm oyster processing by shortening the shipping period and reducing oyster quality. To minimize impacts on Pacific oyster farming, in addition to mitigation measures, local adaptation measures may be required.
Taketoshi Kodama, Atsushi Nishimoto, Ken-ichi Nakamura, Misato Nakae, Naoki Iguchi, Yosuke Igeta, and Yoichi Kogure
Biogeosciences, 20, 3667–3682, https://doi.org/10.5194/bg-20-3667-2023, https://doi.org/10.5194/bg-20-3667-2023, 2023
Short summary
Short summary
Carbon and nitrogen are essential elements for organisms; their stable isotope ratios (13C : 12C, 15N : 14N) are useful tools for understanding turnover and movement in the ocean. In the Sea of Japan, the environment is rapidly being altered by human activities. The 13C : 12C of small organic particles is increased by active carbon fixation, and phytoplankton growth increases the values. The 15N : 14N variations suggest that nitrates from many sources contribute to organic production.
Aubin Thibault de Chanvalon, George W. Luther, Emily R. Estes, Jennifer Necker, Bradley M. Tebo, Jianzhong Su, and Wei-Jun Cai
Biogeosciences, 20, 3053–3071, https://doi.org/10.5194/bg-20-3053-2023, https://doi.org/10.5194/bg-20-3053-2023, 2023
Short summary
Short summary
The intensity of the oceanic trap of CO2 released by anthropogenic activities depends on the alkalinity brought by continental weathering. Between ocean and continent, coastal water and estuaries can limit or favour the alkalinity transfer. This study investigate new interactions between dissolved metals and alkalinity in the oxygen-depleted zone of estuaries.
Joonas J. Virtasalo, Peter Österholm, and Eero Asmala
Biogeosciences, 20, 2883–2901, https://doi.org/10.5194/bg-20-2883-2023, https://doi.org/10.5194/bg-20-2883-2023, 2023
Short summary
Short summary
We mixed acidic metal-rich river water from acid sulfate soils and seawater in the laboratory to study the flocculation of dissolved metals and organic matter in estuaries. Al and Fe flocculated already at a salinity of 0–2 to large organic flocs (>80 µm size). Precipitation of Al and Fe hydroxide flocculi (median size 11 µm) began when pH exceeded ca. 5.5. Mn transferred weakly to Mn hydroxides and Co to the flocs. Up to 50 % of Cu was associated with the flocs, irrespective of seawater mixing.
Moritz Baumann, Allanah Joy Paul, Jan Taucher, Lennart Thomas Bach, Silvan Goldenberg, Paul Stange, Fabrizio Minutolo, and Ulf Riebesell
Biogeosciences, 20, 2595–2612, https://doi.org/10.5194/bg-20-2595-2023, https://doi.org/10.5194/bg-20-2595-2023, 2023
Short summary
Short summary
The sinking velocity of marine particles affects how much atmospheric CO2 is stored inside our oceans. We measured particle sinking velocities in the Peruvian upwelling system and assessed their physical and biochemical drivers. We found that sinking velocity was mainly influenced by particle size and porosity, while ballasting minerals played only a minor role. Our findings help us to better understand the particle sinking dynamics in this highly productive marine system.
Kyle E. Hinson, Marjorie A. M. Friedrichs, Raymond G. Najjar, Maria Herrmann, Zihao Bian, Gopal Bhatt, Pierre St-Laurent, Hanqin Tian, and Gary Shenk
Biogeosciences, 20, 1937–1961, https://doi.org/10.5194/bg-20-1937-2023, https://doi.org/10.5194/bg-20-1937-2023, 2023
Short summary
Short summary
Climate impacts are essential for environmental managers to consider when implementing nutrient reduction plans designed to reduce hypoxia. This work highlights relative sources of uncertainty in modeling regional climate impacts on the Chesapeake Bay watershed and consequent declines in bay oxygen levels. The results demonstrate that planned water quality improvement goals are capable of reducing hypoxia levels by half, offsetting climate-driven impacts on terrestrial runoff.
Cited articles
Atkinson, M. J. and Smith, S. V.: C-N-P ratios of benthic marine plants, Limnol. Oceanogr., 28, 568–574, 1983.
Ayukai, T.: Retention of phytoplankton and planktonic microbes on coral-reefs within the great-barrier-reef, australia, Coral Reefs, 14, 141–147, 1995.
Ban, S. S., Graham, N. A., and Connolly, S. R.: Evidence for multiple stressor interactions and effects on coral reefs, Glob. Change Biol., 20, 681–697, 2014.
Blanco, A. C., Watanabe, A., Nadaoka, K., Motooka, S., Herrera, E. C., and Yamamoto, T.: Estimation of nearshore groundwater discharge and its potential effects on a fringing coral reef, Mar. Pollut. Bull., 62, 770–785, 2011.
Brzezinski, M. A.: The Si-C-N ratio of marine diatoms – interspecific variability and the effect of some environmental variables, J. Phycol., 21, 347–357, 1985.
Burnett, W. C. and Dulaiova, H.: Estimating the dynamics of groundwater input into the coastal zone via continuous radon-222 measurements, J. Environ. Radioactiv., 69, 21–35, 2003.
Costa Jr., O. S., Attrill, M. J., and Nimmo, M.: Seasonal and spatial controls on the delivery of excess nutrients to nearshore and offshore coral reefs of Brazil, J. Marine Syst., 60, 63–74, 2006.
Cuet, P., Atkinson, M. J., Blanchot, J., Casareto, B. E., Cordier, E., Falter, J., Frouin, P., Fujimura, H., Pierret, C., Susuki, Y., and Tourrand, C.: CNP budgets of a coral-dominated fringing reef at La Réunion, France: coupling of oceanic phosphate and groundwater nitrate, Coral Reefs, 30, 45–55, 2011.
D'Elia, C. F., Webb, K. L., and Porter, J. W.: Nitrate-rich groundwater inputs to Discovery Bay, Jamaica: a significant source of N to local coral reefs, B. Mar. Sci., 31, 903–910, 1981.
Dong, J.-D., Zhang, Y.-Y., Wang, Y. S., Wu, M.-L., Zhang, S., and Cai, C.-H.: Chemometry use in the evaluation of the sanya bay water quality, Braz. J. Oceanogr., 58, 339–352, 2010.
Falter, J. L., Atkinson, M. J., and Merrifield, M. A.: Mass-transfer limitation of nutrient uptake by a wave-dominated reef flat community, Limnol. Oceanogr., 49, 1820–1831, 2004.
Froelich, P. N., Bender, M. L., and Luedtke, N. A.: The marine phosphorus cycle, Am. J. Sci., 282, 474–511, 1982.
Genin, A., Monismith, S. G., Reidenbach, M. A., Yahel, G., and Koseff, J. R.: Intense benthic grazing of phytoplankton in a coral reef, Limnol. Oceanogr., 54, 938–951, 2009.
Han, A. Q., Dai, M. H., Kao, S. J., Gan, J. P., Li, Q., Wang, L. F., Zhai, W. D., and Wang, L.: Nutrient dynamics and biological consumption in a large continental shelf system under the influence of both a river plume and coastal upwelling, Limnol. Oceanogr., 57, 486–502, 2012.
Houk, P. and Starmer, J.: Constraints on the diversity and distribution of coral-reef assemblages in the volcanic Northern Mariana Islands, Coral Reefs, 29, 59–70, 2010.
Houk, P., Golbuu, Y., Gorong, B., Gorong, T., and Fillmed, C.: Watershed discharge patterns, secondary consumer abundances, and seagrass habitat condition in Yap, Micronesia, Mar. Pollut. Bull., 71, 209–215, 2013.
Jickells, T. D.: Nutrient biogeochemistry of the coastal zone, Science, 281, 217–222, 1998.
Kelly, R. P. and Moran, S. B.: Seasonal changes in groundwater input to a well-mixed estuary estimated using radium isotopes and implications for coastal nutrient budgets, Limnol. Oceanogr., 47, 1796–1807, 2002.
Lapointe, B. E.: Nutrient thresholds for bottom-up control of macroalgal blooms on coral reefs in Jamaica and southeast Florida, Limnol. Oceanogr., 42, 1119–1131, 1997.
Lewis, J. B.: Measurements of groundwater seepage flux onto a coral reef: spatial and temporal variations, Limnol. Oceanogr., 32, 1165–1169, 1987.
Li, X., Liu, S., Huang, H., Huang, L., Jing, Z., and Zhang, C.: Coral bleaching caused by an abnormal water temperature rise at Luhuitou fringing reef, Sanya Bay, China, Aquat. Ecosyst. Health, 15, 227–233, 2012.
Monismith, S. G., Davis, K. A., Shellenbarger, G. G., Hench, J. L., Nidzieko, N. J., Santoro, A. E., Reidenbach, M. A., Rosman, J. H., Holtzman, R., Martens, C. S., Lindquist, N. L., Southwell, M. W., and Genin, A. : Flow effects on benthic grazing on phytoplankton by a Caribbean reef, Limnol. Oceanogr., 55, 1881–1892, 2010.
Moore, W. S.: Radium isotope measurements using germanium detectors, Nucl. Instrum. Methods, 223, 407–411, 1984.
Papritz, A. and Stein, A.: Spatial prediction by linear kriging, in: Spatial Statistics for Remote Sensing, Remote Sensing and Digital Image Processing, Vol. 1, edited by: Stein, A., Van der Meer, F., and Gorte, B., Springer, Dordrecht, https://doi.org/10.1007/0-306-47647-9_6, 2002.
Paytan, A., Shellenbarger, G. G., Street, J. H., Gonneea, M. E., Davis, K., Young, M. B., and Moore, W. S.: Submarine groundwater discharge: an important source of new inorganic nitrogen to coral reef ecosystems, Limnol. Oceanogr., 51, 343–348, 2006.
Rama and Moore, W. S.: Using the radium quartet for evaluating groundwater input and water exchange in salt marshes, Geochim. Cosmochim. Ac., 60, 4645–4652, 1996.
Redfield, A. C.: The biological control of chemical factors in the environment, Sci. Prog., 11, 150–170, 1960.
Ribes, M., Coma, R., Atkinson, M. J., and Kinzie, R. A.: Sponges and ascidians control removal of particulate organic nitrogen from coral reef water, Limnol. Oceanogr., 50, 1480–1489, 2005.
Santos, I. R., Erler, D., Tait, D., and Eyre, B. D.: Breathing of a coral cay: tracing tidally driven seawater recirculation in permeable coral reef sediments, J. Geophys. Res., 115, C12010, https://doi.org/10.1029/2010JC006510, 2010.
Slomp, C. P. and Van Cappellen, P.: Nutrient inputs to the coastal ocean through submarine groundwater discharge: controls and potential impact, J. Hydrol., 295, 64–86, 2004.
Southwell, M. W., Weisz, J. B., Martens, C. S., and Lindquist, N.: In situ fluxes of dissolved inorganic nitrogen from the sponge community on Conch Reef, Key Largo, Florida, Limnol. Oceanogr., 53, 986–996, 2008.
Titlyanov, E. A. and Titlyanova, T. V.: Changes in the species composition of benthic macroalgal communities of the upper subtidal zone on a coral reef in Sanya Bay (Hainan Island, China) during 2009–2012, Russ. J. Mar. Biol., 39, 413–419, 2013.
Titlyanov, E. A., Titlyanova, T. V., Li, X., Hansen, G. I., and Huang, H.: Seasonal changes in the intertidal algal communities of Sanya Bay (Hainan Island, China), J. Mar. Biol. Assoc. UK, 94, 879–893, 2014.
Titlyanov, E. A., Titlyanova, T. V., Belous, O. S., and Kalita, T. L.: Inventory change (1990s–2010s) in the marine flora of Sanya Bay (Hainan Island, China), J. Mar. Biol. Assoc. UK, 95, 461–470, 2015.
van der Zee, C., Roevros, N., and Chou, L.: Phosphorus speciation, transformation and retention in the Scheldt estuary (Belgium/the Netherlands) from the freshwater tidal limits to the North Sea, Mar. Chem., 106, 76–91, 2007.
Wang, G., Jing, W., Wang, S., Xu, Y., Wang, Z., Zhang, Z., Li, Q., and Dai, M.: Coastal acidification induced by tidal-driven submarine groundwater discharge in a coastal coral reef system, Environ. Sci. Technol., 48, 13069–13075, 2014.
Wang, G., Wang, Z., Zhai, W., Moore, W. S., Li, Q., Yan, X., Qi, D., and Jiang, Y.: Net subterranean estuarine export fluxes of dissolved inorganic C, N, P, Si, and total alkalinity into the Jiulong River estuary, China, Geochim. Cosmochim. Ac., 149, 103–114, 2015.
Wang, G., Wang, S., and Wang, Z.: Significance of submarine groundwater discharge in nutrients budget in tropical Sanya Bay, China, Sustainability, 10, 380, https://doi.org/10.3390/su10020380, 2018.
Wang, H., Dong, J., Wang, Y., Chen, G., and Zhang, Y.: Variations of nutrient contents and their transportation estimate at Sanya Bay, J. Tropical Oceanogr., 25, 90–95, 2005.
Wang, Y., Jing, Z., and Qi, Y.: Coastal upwelling off eastern Hainan Island observed in the summer of 2013, Chinese J. Tropical Oceanogr., 35, 40–49, 2016.
Wu, M.-L., Zhang, Y.-Y., Dong, J.-D., Wang, Y.-S., and Cai, C.-H.: Identification of coastal water quality by self-organizing map in Sanya Bay, South China Sea, Aquat. Ecosyst. Health, 14, 291–297, 2011.
Wu, M.-L., Ling, J., Long, L.-J., Zhang, S., Zhang, Y.-Y., Wang, Y.-S., and Dong, J.-D.: Influence of human activity and monsoon dynamics on spatial and temporal hydrochemistry in tropical coastal waters (Sanya Bay, South China Sea), Chem. Ecol., 28, 375–390, 2012c.
Wu, M.-L., Zhang, Y.-Y., Dong, J.-D., Cai, C.-H., Wang, Y.-S., Long, L.-J., and Zhang, S.: Monsoon-driven dynamics of environmental factors and phytoplankton in tropical Sanya Bay, South China Sea, Oceanol. Hydrobiol. St., 41, 57–66, 2012a.
Wu, M.-L., Zhang, Y.-Y., Long, L.-J., Zhang, S., Wang, Y.-S., Ling, J., and Dong, J.-D.: Identification of coastal water quality, including heavy metals, in the South China Sea, Pol. J. Environ. Stud., 21, 1445–1552, 2012b.
Wyatt, A. S. J., Falter, J. L., Lowe, R. J., Humphries, S., and Waite, A. M.: Oceanographic forcing of nutrient uptake and release over a fringing coral reef, Limnol. Oceanogr., 57, 401–419, 2012.
Zhang, J., Wang, D. R., Jennerjahn, T., and Dsikowitzky, L.: Land–sea interactions at the east coast of Hainan Island, South China Sea: a synthesis, Cont. Shelf Res., 57, 132–142, 2013.
Zhang, Q.: On biogeomorphology of Luhuitou fringing reef of Sanya city, Hainan Island, China, Chinese Sci Bull., 46, 97–101, 2001.
Zhao, M., Yu, K., Zhang, Q., Shi, Q., and Price, G. J.: Long-term decline of a fringing coral reef in the northern South China Sea, J. Coastal Res., 28, 1088–1099, 2012.
Zhao, X., Zhang, J., and Li, G.: Development of the Holocene coral reefs along the southern coast of Hainan Island, Sci. Geol. Sinica, 2, 150–160, 1983.
Zhou, W., Li, T., Cai, C., Huang, L., Wang, H., Xu, J., Dong, J., and Zhang, S.: Spatial and temporal dynamics of phytoplankton and bacterioplankton biomass in Sanya Bay, northern South China Sea, J. Environ. Sci., 21, 595–603, 2009.
Short summary
Time-series observations of nutrients and 228Ra, a groundwater discharge tracer, were carried out from spring to neap tide in the Luhuitou fringing reef at Sanya Bay in the South China Sea. Nitrate, phosphate, and silicate in the water column showed greater diurnal variation during the spring tide. Biological processes predominantly controlled the composition of nutrients, but there was less of an impact in the spring tide due to groundwater discharge in this reef system.
Time-series observations of nutrients and 228Ra, a groundwater discharge tracer, were carried...
Altmetrics
Final-revised paper
Preprint