Articles | Volume 13, issue 1
https://doi.org/10.5194/bg-13-133-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/bg-13-133-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
15 Jan 2016
Research article |
| 15 Jan 2016
Concentration maxima of volatile organic iodine compounds in the bottom layer water and the cold, dense water over the Chukchi Sea in the western Arctic Ocean: a possibility of production related to the degradation of organic matter
Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan
S. Kawasaki
Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan
K. Kuma
Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan
S. Nishino
Institute of Arctic Climate and Environment Research, Japan Agency for
Marine-Earth Science and Technology, Yokosuka, Japan
T. Kikuchi
Institute of Arctic Climate and Environment Research, Japan Agency for
Marine-Earth Science and Technology, Yokosuka, Japan
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Sachi Umezawa, Manami Tozawa, Yuichi Nosaka, Daiki Nomura, Hiroji Onishi, Hiroto Abe, Tetsuya Takatsu, and Atsushi Ooki
Biogeosciences, 20, 421–438, https://doi.org/10.5194/bg-20-421-2023, https://doi.org/10.5194/bg-20-421-2023, 2023
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We conducted repetitive observations in Funka Bay, Japan, during the spring bloom 2019. We found nutrient concentration decreases in the dark subsurface layer during the bloom. Incubation experiments confirmed that diatoms could consume nutrients at a substantial rate, even in darkness. We concluded that the nutrient reduction was mainly caused by nutrient consumption by diatoms in the dark.
Sachi Umezawa, Manami Tozawa, Yuichi Nosaka, Daiki Nomura, Hiroji Onishi, Hiroto Abe, Tetsuya Takatsu, and Atsushi Ooki
Biogeosciences, 20, 421–438, https://doi.org/10.5194/bg-20-421-2023, https://doi.org/10.5194/bg-20-421-2023, 2023
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We conducted repetitive observations in Funka Bay, Japan, during the spring bloom 2019. We found nutrient concentration decreases in the dark subsurface layer during the bloom. Incubation experiments confirmed that diatoms could consume nutrients at a substantial rate, even in darkness. We concluded that the nutrient reduction was mainly caused by nutrient consumption by diatoms in the dark.
Hiroshi Sumata, Frank Kauker, Michael Karcher, Benjamin Rabe, Mary-Louise Timmermans, Axel Behrendt, Rüdiger Gerdes, Ursula Schauer, Koji Shimada, Kyoung-Ho Cho, and Takashi Kikuchi
Ocean Sci., 14, 161–185, https://doi.org/10.5194/os-14-161-2018, https://doi.org/10.5194/os-14-161-2018, 2018
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We estimated spatial and temporal decorrelation scales of temperature and salinity in the Amerasian Basin in the Arctic Ocean. The estimated scales can be applied to representation error assessment in the ocean data assimilation system for the Arctic Ocean.
Naohiro Kosugi, Daisuke Sasano, Masao Ishii, Shigeto Nishino, Hiroshi Uchida, and Hisayuki Yoshikawa-Inoue
Biogeosciences, 14, 5727–5739, https://doi.org/10.5194/bg-14-5727-2017, https://doi.org/10.5194/bg-14-5727-2017, 2017
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Recent variation in air–sea CO2 flux in the Arctic Ocean is focused. In order to understand the relation between sea ice retreat and CO2 chemistry, we conducted hydrographic observations in the Arctic Ocean in 2013. There were relatively high pCO2 surface layer and low pCO2 subsurface layer in the Canada Basin. The former was due to near-equilibration with the atmosphere and the latter primary production. Both were unlikely mixed by disturbance as large sea-ice melt formed strong stratification.
Michiyo Yamamoto-Kawai, Takahisa Mifune, Takashi Kikuchi, and Shigeto Nishino
Biogeosciences, 13, 6155–6169, https://doi.org/10.5194/bg-13-6155-2016, https://doi.org/10.5194/bg-13-6155-2016, 2016
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Seasonal variation of Ω in bottom water in Hope Valley, a biological hotspot in the southern Chukchi Sea, was reconstructed from 2-year-round mooring data of temperature, salinity and oxygen, with empirical equations derived from ship-based observations.
Hiroko Sasaki, Kohei Matsuno, Amane Fujiwara, Misaki Onuka, Atsushi Yamaguchi, Hiromichi Ueno, Yutaka Watanuki, and Takashi Kikuchi
Biogeosciences, 13, 4555–4567, https://doi.org/10.5194/bg-13-4555-2016, https://doi.org/10.5194/bg-13-4555-2016, 2016
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We constructed the habitat models explaining the spatial patterns of the large and small Arctic copepods and the Pacific copepods of the northern Bering Sea and Chukchi Sea. The adequate models show the importance of water masses and sea ice retreat timing. This finding also indicates that earlier sea ice retreat has positive effects on the abundance of all copepod groups in the northern Bering and Chukchi seas, suggesting a change from a pelagic–benthic-type ecosystem to a pelagic–pelagic type.
Shigeto Nishino, Takashi Kikuchi, Amane Fujiwara, Toru Hirawake, and Michio Aoyama
Biogeosciences, 13, 2563–2578, https://doi.org/10.5194/bg-13-2563-2016, https://doi.org/10.5194/bg-13-2563-2016, 2016
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We analysed mooring and ship-based data obtained from a biological hotspot in the southern Chukchi Sea. Mooring data were collected for the first time in this site and were captured during spring and autumn blooms with high chlorophyll a concentrations. The data suggest that a dome-like structure of the bottom water and nutrient regeneration at the bottom play important roles in maintaining the autumn bloom of the biological hotspot.
Naoya Yokoi, Kohei Matsuno, Mutsuo Ichinomiya, Atsushi Yamaguchi, Shigeto Nishino, Jonaotaro Onodera, Jun Inoue, and Takashi Kikuchi
Biogeosciences, 13, 913–923, https://doi.org/10.5194/bg-13-913-2016, https://doi.org/10.5194/bg-13-913-2016, 2016
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We studied short-term changes in the microplankton community in the Chukchi Sea with regards to responses to the strong wind event (SWE) during autumn (September 2013). It is assumed that atmospheric turbulences, such as SWE, may supply sufficient nutrients to the surface layer that subsequently enhance the small bloom under the weak stratification. After the bloom, the dominant diatom community then shifts from centric-dominated to one where centric/pennate are more equal in abundance.
A. Fujiwara, T. Hirawake, K. Suzuki, L. Eisner, I. Imai, S. Nishino, T. Kikuchi, and S.-I. Saitoh
Biogeosciences, 13, 115–131, https://doi.org/10.5194/bg-13-115-2016, https://doi.org/10.5194/bg-13-115-2016, 2016
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This study provides the general relationship between the timing of sea ice retreat and phytoplankton size structure during the marginal ice zone bloom period in the Chukchi and Bering shelves using a satellite remote sensing approach. We also found that not only the length of the ice-free season but also the annual phytoplankton size composition positively correlated with annual net primary production.
K. Matsuno, A. Yamaguchi, S. Nishino, J. Inoue, and T. Kikuchi
Biogeosciences, 12, 4005–4015, https://doi.org/10.5194/bg-12-4005-2015, https://doi.org/10.5194/bg-12-4005-2015, 2015
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We performed high-frequency samplings of zooplankton community and gut pigment of copepods in the Chukchi Sea. Zooplankton showed no changes with a strong wind event and dominant copepods prepared for diapause. Yet, feeding activity of the copepods increased as a result of temporal phytoplankton bloom, enhanced by the wind event. Because of the long generation length of copepods, a smaller effect was detected for their abundance, population, lipid accumulation and gonad maturation.
I. P. Semiletov, N. E. Shakhova, I. I. Pipko, S. P. Pugach, A. N. Charkin, O. V. Dudarev, D. A. Kosmach, and S. Nishino
Biogeosciences, 10, 5977–5996, https://doi.org/10.5194/bg-10-5977-2013, https://doi.org/10.5194/bg-10-5977-2013, 2013
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Biogeochemistry: Coastal Ocean
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
Unusual Hemiaulus Bloom Influences Ocean Productivity in Northeast U.S. Shelf Waters
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
UAV approaches for improved mapping of vegetation cover and estimation of carbon storage of small saltmarshes: examples from Loch Fleet, northeast Scotland
Estuarine flocculation dynamics of organic carbon and metals from boreal acid sulfate soils
Drivers of particle sinking velocities in the Peruvian upwelling system
Marine anoxia initiates giant sulfur-bacteria mat proliferation and associated changes in benthic nitrogen, sulfur, and iron cycling in the Santa Barbara Basin, California Borderland
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Temporal and spatial evolution of bottom-water hypoxia in the St Lawrence estuarine system
Significant nutrient consumption in the dark subsurface layer during a diatom bloom: a case study on Funka Bay, Hokkaido, Japan
Contrasts in dissolved, particulate, and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf
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Unprecedented summer hypoxia in southern Cape Cod Bay: an ecological response to regional climate change?
Interannual variabilities, long-term trends, and regulating factors of low-oxygen conditions in the coastal waters off Hong Kong
Causes of the extensive hypoxia in the Gulf of Riga in 2018
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Contrasting patterns of carbon cycling and dissolved organic matter processing in two phytoplankton–bacteria communities
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Seasonal dispersal of fjord meltwaters as an important source of iron and manganese to coastal Antarctic phytoplankton
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
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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
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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
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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
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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
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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
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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
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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.
S. Alejandra Castillo Cieza, Rachel H. R. Stanley, Pierre Marrec, Diana N. Fontaine, E. Taylor Crockford, Dennis J. McGillicuddy, Arshia Mehta, Susanne Menden-Deuer, Emily E. Peacock, Tatiana A. Rynearson, Zoe O. Sandwith, Weifeng Zhang, and Heidi M. Sosik
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-153, https://doi.org/10.5194/bg-2023-153, 2023
Revised manuscript accepted for BG
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The coastal ocean in northeastern USA provides many services, including fisheries and habitat for threatened species. In summer 2019, a bloom occurred of an unusual large 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 maybe become more prevalent as the ocean warms due to climate change.
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
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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
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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.
William Hiles, Lucy Catherine Miller, Craig Smeaton, and William Edward Newns Austin
EGUsphere, https://doi.org/10.5194/egusphere-2023-1185, https://doi.org/10.5194/egusphere-2023-1185, 2023
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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.
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
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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
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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.
David J. Yousavich, De'Marcus Robinson, Xuefeng Peng, Sebastian J. E. Krause, Frank Wenzhoefer, Felix Janßen, Na Liu, Jonathan Tarn, Frank Kinnaman, David L. Valentine, and Tina Treude
EGUsphere, https://doi.org/10.5194/egusphere-2023-1198, https://doi.org/10.5194/egusphere-2023-1198, 2023
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Declining oxygen 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 oxygen depletion events through their unique chemoautotrophic metabolism. Our study shows how changes in seafloor microbiology and geochemistry brought on by declining oxygen concentrations can help these mats grow, and how that growth affects the basin.
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
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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.
Linquan Mu, Jaime B. Palter, and Hongjie Wang
Biogeosciences, 20, 1963–1977, https://doi.org/10.5194/bg-20-1963-2023, https://doi.org/10.5194/bg-20-1963-2023, 2023
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Enhancing ocean alkalinity accelerates carbon dioxide removal from the atmosphere. We hypothetically added alkalinity to the Amazon River and examined the increment of the carbon uptake by the Amazon plume. We also investigated the minimum alkalinity addition in which this perturbation at the river mouth could be detected above the natural variability.
Ting Wang, Buyun Du, Inke Forbrich, Jun Zhou, Joshua Polen, Elsie M. Sunderland, Prentiss H. Balcom, Celia Y. Chen, and Daniel Obrist
EGUsphere, https://doi.org/10.5194/egusphere-2023-720, https://doi.org/10.5194/egusphere-2023-720, 2023
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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. While belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.
Karl M. Attard, Anna Lyssenko, and Iván F. Rodil
Biogeosciences, 20, 1713–1724, https://doi.org/10.5194/bg-20-1713-2023, https://doi.org/10.5194/bg-20-1713-2023, 2023
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Aquatic plants produce a large amount of organic matter through photosynthesis that, following erosion, is deposited on the seafloor. In this study, we show that plant detritus can trigger low-oxygen conditions (hypoxia) in shallow coastal waters, making conditions challenging for most marine animals. We propose that the occurrence of hypoxia may be underestimated because measurements typically do not consider the region closest to the seafloor, where detritus accumulates.
Pamela Linford, Iván Pérez-Santos, Paulina Montero, Patricio 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
EGUsphere, https://doi.org/10.5194/egusphere-2023-706, https://doi.org/10.5194/egusphere-2023-706, 2023
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The Patagonian fjord is one world region where low-oxygen water and hypoxia conditions is observed. An in-situ data set was used to quantify the mechanism involved in the presence of low-oxygen water and hypoxic 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.
M. James McLaughlin, Cindy Bessey, Gary A. Kendrick, John Keesing, and Ylva S. Olsen
Biogeosciences, 20, 1011–1026, https://doi.org/10.5194/bg-20-1011-2023, https://doi.org/10.5194/bg-20-1011-2023, 2023
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Coral reefs face increasing pressures from environmental change at present. The coral reef framework is produced by corals and calcifying algae. The Kimberley region of Western Australia has escaped land-based anthropogenic impacts. Specimens of the dominant coral and algae were collected from Browse Island's reef platform and incubated in mesocosms to measure calcification and production patterns of oxygen. This study provides important data on reef building and climate-driven effects.
Patricia Ayón Dejo, Elda Luz Pinedo Arteaga, Anna Schukat, Jan Taucher, Rainer Kiko, Helena Hauss, Sabrina Dorschner, Wilhelm Hagen, Mariona Segura-Noguera, and Silke Lischka
Biogeosciences, 20, 945–969, https://doi.org/10.5194/bg-20-945-2023, https://doi.org/10.5194/bg-20-945-2023, 2023
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Ocean upwelling regions are highly productive. With ocean warming, severe changes in upwelling frequency and/or intensity and expansion of accompanying oxygen minimum zones are projected. In a field experiment off Peru, we investigated how different upwelling intensities affect the pelagic food web and found failed reproduction of dominant zooplankton. The changes projected could severely impact the reproductive success of zooplankton communities and the pelagic food web in upwelling regions.
Mathilde Jutras, Alfonso Mucci, Gwenaëlle Chaillou, William A. Nesbitt, and Douglas W. R. Wallace
Biogeosciences, 20, 839–849, https://doi.org/10.5194/bg-20-839-2023, https://doi.org/10.5194/bg-20-839-2023, 2023
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The deep waters of the lower St Lawrence Estuary and gulf have, in the last decades, experienced a strong decline in their oxygen concentration. Below 65 µmol L-1, the waters are said to be hypoxic, with dire consequences for marine life. We show that the extent of the hypoxic zone shows a seven-fold increase in the last 20 years, reaching 9400 km2 in 2021. After a stable period at ~ 65 µmol L⁻¹ from 1984 to 2019, the oxygen level also suddenly decreased to ~ 35 µmol L-1 in 2020.
Sachi Umezawa, Manami Tozawa, Yuichi Nosaka, Daiki Nomura, Hiroji Onishi, Hiroto Abe, Tetsuya Takatsu, and Atsushi Ooki
Biogeosciences, 20, 421–438, https://doi.org/10.5194/bg-20-421-2023, https://doi.org/10.5194/bg-20-421-2023, 2023
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We conducted repetitive observations in Funka Bay, Japan, during the spring bloom 2019. We found nutrient concentration decreases in the dark subsurface layer during the bloom. Incubation experiments confirmed that diatoms could consume nutrients at a substantial rate, even in darkness. We concluded that the nutrient reduction was mainly caused by nutrient consumption by diatoms in the dark.
Dirk Jong, Lisa Bröder, Tommaso Tesi, Kirsi H. Keskitalo, Nikita Zimov, Anna Davydova, Philip Pika, Negar Haghipour, Timothy I. Eglinton, and Jorien E. Vonk
Biogeosciences, 20, 271–294, https://doi.org/10.5194/bg-20-271-2023, https://doi.org/10.5194/bg-20-271-2023, 2023
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With this study, we want to highlight the importance of studying both land and ocean together, and water and sediment together, as these systems function as a continuum, and determine how organic carbon derived from permafrost is broken down and its effect on global warming. Although on the one hand it appears that organic carbon is removed from sediments along the pathway of transport from river to ocean, it also appears to remain relatively ‘fresh’, despite this removal and its very old age.
Georgia Filippi, Manos Dassenakis, Vasiliki Paraskevopoulou, and Konstantinos Lazogiannis
Biogeosciences, 20, 163–189, https://doi.org/10.5194/bg-20-163-2023, https://doi.org/10.5194/bg-20-163-2023, 2023
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The pollution of the western Saronikos Gulf from heavy metals has been examined through the study of marine sediment cores. It is a deep gulf (maximum depth 440 m) near Athens affected by industrial and volcanic activity. Eight cores were received from various stations and depths and analysed for their heavy metal content and geochemical characteristics. The results were evaluated by using statistical methods, environmental indicators and comparisons with old data.
Jing He and Michael D. Tyka
Biogeosciences, 20, 27–43, https://doi.org/10.5194/bg-20-27-2023, https://doi.org/10.5194/bg-20-27-2023, 2023
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Recently, ocean alkalinity enhancement (OAE) has gained interest as a scalable way to address the urgent need for negative CO2 emissions. In this paper we examine the capacity of different coastlines to tolerate alkalinity enhancement and the time scale of CO2 uptake following the addition of a given quantity of alkalinity. The results suggest that OAE has significant potential and identify specific favorable and unfavorable coastlines for its deployment.
Arnaud Laurent, Haiyan Zhang, and Katja Fennel
Biogeosciences, 19, 5893–5910, https://doi.org/10.5194/bg-19-5893-2022, https://doi.org/10.5194/bg-19-5893-2022, 2022
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The Changjiang is the main terrestrial source of nutrients to the East China Sea (ECS). Nutrient delivery to the ECS has been increasing since the 1960s, resulting in low oxygen (hypoxia) during phytoplankton decomposition in summer. River phosphorus (P) has increased less than nitrogen, and therefore, despite the large nutrient delivery, phytoplankton growth can be limited by the lack of P. Here, we investigate this link between P limitation, phytoplankton production/decomposition, and hypoxia.
Coline Poppeschi, Guillaume Charria, Anne Daniel, Romaric Verney, Peggy Rimmelin-Maury, Michaël Retho, Eric Goberville, Emilie Grossteffan, and Martin Plus
Biogeosciences, 19, 5667–5687, https://doi.org/10.5194/bg-19-5667-2022, https://doi.org/10.5194/bg-19-5667-2022, 2022
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This paper aims to understand interannual changes in the initiation of the phytoplankton growing period (IPGP) in the current context of global climate changes over the last 20 years. An important variability in the timing of the IPGP is observed with a trend towards a later IPGP during this last decade. The role and the impact of extreme events (cold spells, floods, and wind burst) on the IPGP is also detailed.
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 Discuss., https://doi.org/10.5194/bg-2022-237, https://doi.org/10.5194/bg-2022-237, 2022
Revised manuscript accepted for BG
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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.
Lin Yang, Jing Zhang, Anja Engel, and Gui-Peng Yang
Biogeosciences, 19, 5251–5268, https://doi.org/10.5194/bg-19-5251-2022, https://doi.org/10.5194/bg-19-5251-2022, 2022
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Enrichment factors of dissolved organic matter (DOM) in the eastern marginal seas of China exhibited a significant spatio-temporal variation. Photochemical and enrichment processes co-regulated DOM enrichment in the sea-surface microlayer (SML). Autochthonous DOM was more frequently enriched in the SML than terrestrial DOM. DOM in the sub-surface water exhibited higher aromaticity than that in the SML.
Mona Norbisrath, Johannes Pätsch, Kirstin Dähnke, Tina Sanders, Gesa Schulz, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 19, 5151–5165, https://doi.org/10.5194/bg-19-5151-2022, https://doi.org/10.5194/bg-19-5151-2022, 2022
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Total alkalinity (TA) regulates the oceanic storage capacity of atmospheric CO2. TA is also metabolically generated in estuaries and influences coastal carbon storage through its inflows. We used water samples and identified the Hamburg port area as the one with highest TA generation. Of the overall riverine TA load, 14 % is generated within the estuary. Using a biogeochemical model, we estimated potential effects on the coastal carbon storage under possible anthropogenic and climate changes.
Le Zhang and Z. George Xue
Biogeosciences, 19, 4589–4618, https://doi.org/10.5194/bg-19-4589-2022, https://doi.org/10.5194/bg-19-4589-2022, 2022
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We adopt a high-resolution carbon model for the Gulf of Mexico (GoM) and calculate the decadal trends of important carbon system variables in the GoM from 2001 to 2019. The GoM surface CO2 values experienced a steady increase over the past 2 decades, and the ocean surface pH is declining. Although carbonate saturation rates remain supersaturated with aragonite, they show a slightly decreasing trend. The northern GoM is a stronger carbon sink than we thought.
Michael M. Whitney
Biogeosciences, 19, 4479–4497, https://doi.org/10.5194/bg-19-4479-2022, https://doi.org/10.5194/bg-19-4479-2022, 2022
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Coastal hypoxia is a major environmental problem of increasing severity. The 21st-century projections analyzed indicate global coastal waters will warm and experience rapid declines in oxygen. The forecasted median coastal trends for increasing sea surface temperature and decreasing oxygen capacity are 48 % and 18 % faster than the rates observed over the last 4 decades. Existing hypoxic areas are expected to worsen, and new hypoxic areas likely will emerge under these warming-related pressures.
Bryce Van Dam, Nele Lehmann, Mary A. Zeller, Andreas Neumann, Daniel Pröfrock, Marko Lipka, Helmuth Thomas, and Michael Ernst Böttcher
Biogeosciences, 19, 3775–3789, https://doi.org/10.5194/bg-19-3775-2022, https://doi.org/10.5194/bg-19-3775-2022, 2022
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We quantified sediment–water exchange at shallow sites in the North and Baltic seas. We found that porewater irrigation rates in the former were approximately twice as high as previously estimated, likely driven by relatively high bioirrigative activity. In contrast, we found small net fluxes of alkalinity, ranging from −35 µmol m−2 h−1 (uptake) to 53 µmol m−2 h−1 (release). We attribute this to low net denitrification, carbonate mineral (re-)precipitation, and sulfide (re-)oxidation.
Jiaying Abby Guo, Robert Strzepek, Anusuya Willis, Aaron Ferderer, and Lennart Thomas Bach
Biogeosciences, 19, 3683–3697, https://doi.org/10.5194/bg-19-3683-2022, https://doi.org/10.5194/bg-19-3683-2022, 2022
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Ocean alkalinity enhancement is a CO2 removal method with significant potential, but it can lead to a perturbation of the ocean with trace metals such as nickel. This study tested the effect of increasing nickel concentrations on phytoplankton growth and photosynthesis. We found that the response to nickel varied across the 11 phytoplankton species tested here, but the majority were rather insensitive. We note, however, that responses may be different under other experimental conditions.
Malcolm E. Scully, W. Rockwell Geyer, David Borkman, Tracy L. Pugh, Amy Costa, and Owen C. Nichols
Biogeosciences, 19, 3523–3536, https://doi.org/10.5194/bg-19-3523-2022, https://doi.org/10.5194/bg-19-3523-2022, 2022
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For two consecutive summers, the bottom waters in southern Cape Cod Bay became severely depleted of dissolved oxygen. Low oxygen levels in bottom waters have never been reported in this area before, and this unprecedented occurrence is likely the result of a new algae species that recently began blooming during the late-summer months. We present data suggesting that blooms of this new species are the result of regional climate change including warmer waters and changes in summer winds.
Zheng Chen, Bin Wang, Chuang Xu, Zhongren Zhang, Shiyu Li, and Jiatang Hu
Biogeosciences, 19, 3469–3490, https://doi.org/10.5194/bg-19-3469-2022, https://doi.org/10.5194/bg-19-3469-2022, 2022
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Deterioration of low-oxygen conditions in the coastal waters off Hong Kong was revealed by monitoring data over two decades. The declining wind forcing and the increasing nutrient input contributed significantly to the areal expansion and intense deterioration of low-oxygen conditions. Also, the exacerbated eutrophication drove a shift in the dominant source of organic matter from terrestrial inputs to in situ primary production, which has probably led to an earlier onset of hypoxia in summer.
Stella-Theresa Stoicescu, Jaan Laanemets, Taavi Liblik, Māris Skudra, Oliver Samlas, Inga Lips, and Urmas Lips
Biogeosciences, 19, 2903–2920, https://doi.org/10.5194/bg-19-2903-2022, https://doi.org/10.5194/bg-19-2903-2022, 2022
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Coastal basins with high input of nutrients often suffer from oxygen deficiency. In summer 2018, the extent of oxygen depletion was exceptional in the Gulf of Riga. We analyzed observational data and found that extensive oxygen deficiency appeared since the water layer close to the seabed, where oxygen is consumed, was separated from the surface layer. The problem worsens if similar conditions restricting vertical transport of oxygen occur more frequently in the future.
Justin C. Tiano, Jochen Depestele, Gert Van Hoey, João Fernandes, Pieter van Rijswijk, and Karline Soetaert
Biogeosciences, 19, 2583–2598, https://doi.org/10.5194/bg-19-2583-2022, https://doi.org/10.5194/bg-19-2583-2022, 2022
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This study gives an assessment of bottom trawling on physical, chemical, and biological characteristics in a location known for its strong currents and variable habitats. Although trawl gears only removed the top 1 cm of the seabed surface, impacts on reef-building tubeworms significantly decreased carbon and nutrient cycling. Lighter trawls slightly reduced the impact on fauna and nutrients. Tubeworms were strongly linked to biogeochemical and faunal aspects before but not after trawling.
Inda Brinkmann, Christine Barras, Tom Jilbert, Tomas Næraa, K. Mareike Paul, Magali Schweizer, and Helena L. Filipsson
Biogeosciences, 19, 2523–2535, https://doi.org/10.5194/bg-19-2523-2022, https://doi.org/10.5194/bg-19-2523-2022, 2022
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The concentration of the trace metal barium (Ba) in coastal seawater is a function of continental input, such as riverine discharge. Our geochemical records of the severely hot and dry year 2018, and following wet year 2019, reveal that prolonged drought imprints with exceptionally low Ba concentrations in benthic foraminiferal calcium carbonates of coastal sediments. This highlights the potential of benthic Ba / Ca to trace past climate extremes and variability in coastal marine records.
Shichao Tian, Birgit Gaye, Jianhui Tang, Yongming Luo, Wenguo Li, Niko Lahajnar, Kirstin Dähnke, Tina Sanders, Tianqi Xiong, Weidong Zhai, and Kay-Christian Emeis
Biogeosciences, 19, 2397–2415, https://doi.org/10.5194/bg-19-2397-2022, https://doi.org/10.5194/bg-19-2397-2022, 2022
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We constrain the nitrogen budget and in particular the internal sources and sinks of nitrate in the Bohai Sea by using a mass-based and dual stable isotope approach based on δ15N and δ18O of nitrate. Based on available mass fluxes and isotope data an updated nitrogen budget is proposed. Compared to previous estimates, it is more complete and includes the impact of the interior cycle (nitrification) on the nitrate pool. The main external nitrogen sources are rivers contributing 19.2 %–25.6 %.
Gesa Schulz, Tina Sanders, Justus E. E. van Beusekom, Yoana G. Voynova, Andreas Schöl, and Kirstin Dähnke
Biogeosciences, 19, 2007–2024, https://doi.org/10.5194/bg-19-2007-2022, https://doi.org/10.5194/bg-19-2007-2022, 2022
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Estuaries can significantly alter nutrient loads before reaching coastal waters. Our study of the heavily managed Ems estuary (Northern Germany) reveals three zones of nitrogen turnover along the estuary with water-column denitrification in the most upstream hyper-turbid part, nitrate production in the middle reaches and mixing/nitrate uptake in the North Sea. Suspended particulate matter was the overarching control on nitrogen cycling in the hyper-turbid estuary.
Wiley Evans, Geoffrey T. Lebon, Christen D. Harrington, Yuichiro Takeshita, and Allison Bidlack
Biogeosciences, 19, 1277–1301, https://doi.org/10.5194/bg-19-1277-2022, https://doi.org/10.5194/bg-19-1277-2022, 2022
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Information on the marine carbon dioxide system along the northeast Pacific Inside Passage has been limited. To address this gap, we instrumented an Alaskan ferry in order to characterize the marine carbon dioxide system in this region. Data over a 2-year period were used to assess drivers of the observed variability, identify the timing of severe conditions, and assess the extent of contemporary ocean acidification as well as future levels consistent with a 1.5 °C warmer climate.
Melissa Ward, Tye L. Kindinger, Heidi K. Hirsh, Tessa M. Hill, Brittany M. Jellison, Sarah Lummis, Emily B. Rivest, George G. Waldbusser, Brian Gaylord, and Kristy J. Kroeker
Biogeosciences, 19, 689–699, https://doi.org/10.5194/bg-19-689-2022, https://doi.org/10.5194/bg-19-689-2022, 2022
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Here, we synthesize the results from 62 studies reporting in situ rates of seagrass metabolism to highlight spatial and temporal variability in oxygen fluxes and inform efforts to use seagrass to mitigate ocean acidification. Our analyses suggest seagrass meadows are generally autotrophic and variable in space and time, and the effects on seawater oxygen are relatively small in magnitude.
Tianfei Xue, Ivy Frenger, A. E. Friederike Prowe, Yonss Saranga José, and Andreas Oschlies
Biogeosciences, 19, 455–475, https://doi.org/10.5194/bg-19-455-2022, https://doi.org/10.5194/bg-19-455-2022, 2022
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The Peruvian system supports 10 % of the world's fishing yield. In the Peruvian system, wind and earth’s rotation bring cold, nutrient-rich water to the surface and allow phytoplankton to grow. But observations show that it grows worse at high upwelling. Using a model, we find that high upwelling happens when air mixes the water the most. Then phytoplankton is diluted and grows slowly due to low light and cool upwelled water. This study helps to estimate how it might change in a warming climate.
Shao-Min Chen, Ulf Riebesell, Kai G. Schulz, Elisabeth von der Esch, Eric P. Achterberg, and Lennart T. Bach
Biogeosciences, 19, 295–312, https://doi.org/10.5194/bg-19-295-2022, https://doi.org/10.5194/bg-19-295-2022, 2022
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Oxygen minimum zones in the ocean are characterized by enhanced carbon dioxide (CO2) levels and are being further acidified by increasing anthropogenic atmospheric CO2. Here we report CO2 system measurements in a mesocosm study offshore Peru during a rare coastal El Niño event to investigate how CO2 dynamics may respond to ongoing ocean deoxygenation. Our observations show that nitrogen limitation, productivity, and plankton community shift play an important role in driving the CO2 dynamics.
Paula Maria Salgado-Hernanz, Aurore Regaudie-de-Gioux, David Antoine, and Gotzon Basterretxea
Biogeosciences, 19, 47–69, https://doi.org/10.5194/bg-19-47-2022, https://doi.org/10.5194/bg-19-47-2022, 2022
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For the first time, this study presents the characteristics of primary production in coastal regions of the Mediterranean Sea based on satellite-borne observations for the period 2002–2016. The study concludes that there are significant spatial and temporal variations among different regions. Quantifying primary production is of special importance in the marine food web and in the sequestration of carbon dioxide from the atmosphere to the deep waters.
Samu Elovaara, Eeva Eronen-Rasimus, Eero Asmala, Tobias Tamelander, and Hermanni Kaartokallio
Biogeosciences, 18, 6589–6616, https://doi.org/10.5194/bg-18-6589-2021, https://doi.org/10.5194/bg-18-6589-2021, 2021
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Dissolved organic matter (DOM) is a significant carbon pool in the marine environment. The composition of the DOM pool, as well as its interaction with microbes, is complex, yet understanding it is important for understanding global carbon cycling. This study shows that two phytoplankton species have different effects on the composition of the DOM pool and, through the DOM they produce, on the ensuing microbial community. These communities in turn have different effects on DOM composition.
Yuan Dong, Qian P. Li, Zhengchao Wu, Yiping Shuai, Zijia Liu, Zaiming Ge, Weiwen Zhou, and Yinchao Chen
Biogeosciences, 18, 6423–6434, https://doi.org/10.5194/bg-18-6423-2021, https://doi.org/10.5194/bg-18-6423-2021, 2021
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Temporal change of plankton growth and grazing are less known in the coastal ocean, not to mention the relevant controlling mechanisms. Here, we performed monthly size-specific dilution experiments outside a eutrophic estuary over a 1-year cycle. Phytoplankton growth was correlated to nutrients and grazing mortality to total chlorophyll a. A selective grazing on small cells may be important for maintaining high abundance of large-chain-forming diatoms in this eutrophic system.
Kiefer O. Forsch, Lisa Hahn-Woernle, Robert M. Sherrell, Vincent J. Roccanova, Kaixuan Bu, David Burdige, Maria Vernet, and Katherine A. Barbeau
Biogeosciences, 18, 6349–6375, https://doi.org/10.5194/bg-18-6349-2021, https://doi.org/10.5194/bg-18-6349-2021, 2021
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We show that for an unperturbed cold western Antarctic Peninsula fjord, the seasonality of iron and manganese is linked to the dispersal of metal-rich meltwater sources. Geochemical measurements of trace metals in meltwaters, porewaters, and seawater, collected during two expeditions, showed a seasonal cycle of distinct sources. Finally, model results revealed that the dispersal of surface meltwater and meltwater plumes originating from under the glacier is sensitive to katabatic wind events.
Cited articles
Amachi, S., Muramatsu, Y., Akiyama, Y., Miyazaki, K., Yoshiki, S., Hanada,
S., Kamagata, Y., Ban-nai, T., Shinoyama, H., and Fujii, T.: Isolation of
iodide-oxidizing bacteria from iodide-rich natural gas brines and seawaters,
Microb. Ecol., 49, 547–557, https://doi.org/10.1007/s00248-004-0056-0, 2005.
Anderson, L. G., Andersson, P. S., Bjork, G., Jones, E. P., Jutterstrom, S.,
and Wahlstrom, I.: Source and formation of the upper halocline of the Arctic
Ocean, J. Geophys. Res., 118, 410–421, https://doi.org/10.1029/2012JC008291, 2013.
Anschutz, P., Sundby, B., Lefrancois, L., Luther, G.W., and Mucci, A.:
Interactions between metal oxides and species of nitrogen and iodine in
bioturbated marine sediments, Geochim. Cosmochim. Acta, 64, 2751–2763, https://doi.org/10.1016/S0016-7037(00)00400-2, 2000.
Archer, S. D., Goldson, L. E., Liddicoat, M. I., Cummings, D. G., and
Nightingale, P. D.: Marked seasonality in the concentrations and sea-to-air
flux of volatile iodocarbon compounds in the western English Channel, J.
Geophys. Res., 112, C08009, https://doi.org/10.1029/2006JC003963, 2007.
Atkinson, H. M., Hughes, C., Shaw, M. J., Roscoe, H. K., Carpenter, L. J., and
Liss, P. S.: Halocarbons associated with Arctic sea ice, Deep-Sea Res., 92,
162–175, https://doi.org/10.1016/j.dsr.2014.05.012, 2014.
Carpenter, L. J., Sturges, W. T., Penkett, S. A., Liss, P. S., Alicke, B.,
Hebestreit, K., and Platt U.: Short-lived alkyl iodides and bromides at Mace
Head, Ireland: Links to biogenic sources and halogen oxide production, J. Geophys. Res.,
104, 1679–1689, https://doi.org/10.1029/98JD02746, 1999.
Carpenter, L. J., Hopkins, J. R., Jones, C. E., Lewis, A. C., Parthipan, R.,
Wevill, D. J., Poissant, L., Pilote, M., and Constant, P.: Abiotic source of
reactive organic halogens in the sub-arctic atmosphere, Environ. Sci.
Technol. 39, 8812–8816, https://doi.org/10.1021/es050918w, 2005.
Christman, G. D., Cottrell, M. T., Popp, B. N., Gier, E., and Kirchman, D. L.:
Abundance, Diversity, and Activity of Ammonia-Oxidizing Prokaryotes in the
Coastal Arctic Ocean in Summer and Winter, Appl. Environ. Microbiol., 77, 2026–2034, https://doi.org/10.1128/AEM.01907-10, 2011.
Codispoti, L. A., Flagg, C., Kelly, V., and Swift, J. H.: Hydrographic
conditions during the 2002 SBI process experiments, Deep-Sea Res. Pt. II, 52,
3199–3226, https://doi.org/10.1016/j.dsr2.2005.10.007, 2005.
Cota, G. F., Pomeroy, L. R., Harrison, W. G., Jones, E. P., Peters, F., Sheldon,
W. M., and Weingartner, T. R.: Nutrients, primary production and microbial
heterotrophy in the southeastern Chukchi Sea: Arctic summer nutrient
depletion and heterotrophy, Mar. Ecol.-Prog. Ser., 135, 247–258, https://doi.org/10.3354/meps135247, 1996.
Fuse, H., Inoue, H., Murakami, K., Takimura, O., and Yamaoka, Y.:Production
of free and organic iodine by Roseovarius spp., FEMS Microbiol. Lett., 229, 189–194,
https://doi.org/10.1016/S0378-1097(03)00839-5, 2003.
Grebmeier, J. M., McRoy, C. P., and Feder, H. M.: Pelagic-benthic coupling on
the shelf of the northern Bering and Chukchi Seas I., Food supply source and
benthic biomass, Mar. Ecol.-Prog. Ser., 48, 57–67, 1988.
Grebmeier, J. M., Feder, H. M., and McRoy, C. P.: Pelagic-benthic coupling on
the shelf of the northern Bering and Chukchi Seas II., Benthic community
structure, Mar. Ecol.-Prog. Ser., 51, 253–268, 1989.
Grebmeier, J. M., Bluhm, B. A., Cooper, L. W., Danielson, S., Arrigo, K. R.,
Blanchard, A. L., Clarke, J. T., Day, R. H., Frey, K. E., Gradinger, R. R.,
Kedra, M., Konar, B., Kuletz, K. J., Lee, S. H., Lovvorn, J. R., Norcross,
B. L., and Okkonen, S. R.:Ecosystem Characteristics and Processes Facilitating
Persistent Macrobenthic Biomass Hotspots and Associated Benthivory in the
Pacific, Arctic. Prog. Oceanogr., 136, 92–114,
https://doi.org/10.1016/j.pocean.2015.05.006, 2015.
Happell, J. D. and Wallace, D. W. R.: Methyl iodide in the
Greenland/Norwegian Seas and the tropical Atlantic Ocean: Evidence for
photochemical production, Geophys. Res. Lett., 23, 2105–2108, https://doi.org/10.1029/2006JC003963, 1996.
Hioki, N., Kuma, K., Morita, Y., Sasayama, R., Ooki, A., Kondo, Y., Obata,
H., Nishioka, J., Yamashita, Y., Nishino, S., Kikuchi, T., and Aoyama, M.:
Laterally spreading iron, humic-like dissolved organic matter and nutrients
in cold, dense subsurface water of the Arctic Ocean, Scientific Reports, 4,
6775, https://doi.org/10.1038/srep06775, 2014.
Hughes, C., Malin, G., Turley, C. M., Keely, B. J., and Nightingale, P. D.: The
production of volatile iodocarbons by biogenic marine aggregates, Liminol.
Oceanogr., 53, 867–872, https://doi.org/10.4319/lo.2008.53.2.0867, 2008.
Hydes, D. J., Aoyama, M., Aminot, A., Bakker, K., Becker, S., Coverly, S.,
Daniel, A., Dickson, A. G., Grosso, O., Kerouel, R., van Ooijen, J., Sato,
K., Tanhua, T., Woodward, E. M. S., and Zhang, J. Z.: Determination of
dissolved nutrients (N, P, Si) in seawater with high precision and
inter-comparability using gas-segmented continuous flow analysers. The
GO-SHIP Repeat Hydrography Manual: A Collection of Expert Reports and
Guidelines, ICPO publ, Ser. no. 134, edited by: Hood, E. M., Sabine, C. L., and Sloyan,
B. M., IOCCP Rep. 14, U. N. Educ.Sci. and Cult. Organ.
Intergov. Oceanotr. Comm., Paris, 1–88, 2010.
Jones, C. E. and Carpenter, L. J.: Solar photolysis of CH2I2, CH2ICI, and
CH2IBr in water, saltwater, and seawater, Environ. Sci. Technol., 39,
6130–6137, https://doi.org/10.1021/es050563g, 2005.
Karlsson, A., Theorin, M., and Abrahamsson, K.: Distribution, transport, and
production of volatile halocarbons in the upper waters of the ice-covered
high Arctic Ocean, Global Biogeochem. Cy., 27, 1246–1261, https://doi.org/10.1002/2012GB004519, 2013.
Kudo, I., Yoshimura, T., Lee, C.W., Yanada, M., and Maita, Y.: Nutrient
regeneration at bottom after a massive spring bloom in a subarctic coastal
environment, Funka Bay, Japan, J. Oceanogr. 63, 791–801, https://doi.org/10.1007/s10872-007-0067-9, 2007.
Manley, S. L. and de la Cuesta, J. L.: Methyl iodide production from marine
phytoplankton cultures, Limnol. Oceanogr., 42, 142–147,
https://doi.org/10.1029/2006JC003963, 1997.
Mattson, E., Karlsson, A., Smith, W. O., and Abrahamsson, K.: The
relationship between biophysical variables and halocarbon distributions in
the waters of the Amundsen and Ross Seas, Antarctica, Mar. Chem. 140, 1–9,
https://doi.org/10.1016/j.marchem.2012.07.002, 2012.
Moore, R. M., Webb, M., Tokarczyk, R., and Wever, R.: Bromoperoxidase and
iodoperoxidase enzymes and production of halogenated methanes in marine
diatom cultures, J. Geophys. Res. 101, 20899–20908, https://doi.org/10.1029/96JC01248,
1996.
Nishino, S., Shimada, K., and Itoh, M.: Use of ammonium and other nitrogen
tracers to investigate the spreading of shelf waters in the western Arctic
halocline, J. Geophys. Res., 110, C10005, https://doi.org/10.1029/2003JC002118, 2005.
Ooki, A. and Yokouchi Y.: Dichloromethane in the Indian Ocean: Evidence for
in-situ production in seawater, Mar. Chem., 124, 119–124, https://doi.org/10.1016/j.marchem.2011.01.001, 2011a.
Ooki, A. and Yokouchi, Y.: Determination of Henry's law constant of
halocarbons in seawater and analysis of sea-to-air flux of iodoethane
(C2H5I) in the Indian and Southern oceans based on partial pressure
measurements, Geochem. J., 45, E1–E7, 2011b.
Schall, C. and Heumann, K. G.: GC determination of volatile organoiodine
and organobromine compounds in Arctic seawater and air samples, Fresenius, J. Anal. Chem., 346,
717–722, https://doi.org/10.1016/S0967-0645(02)00204-7, 1993.
Souza, A. C., Gardner, W. S., and Dunton, K. H.: Rates of nitrification and
ammonium dynamics in northeastern Chukchi Sea shelf waters, Deep Sea Res.,
102, 68–76, https://doi.org/10.1016/j.dsr2.2013.12.017, 2014.
Spicer, C. W., Plastridge, R. A., Foster, K. L., Finlayson-Pitts, B. J.,
Bottenheim, J. W. Grannas, A. M., and Shepson, P. B.: Molecular halogens before
and during ozone depletion events in the Arctic at polar sunrise:
concentrations and sources, Atmos. Environ., 36, 2721–2731, https://doi.org/10.1016/S1352-2310(02)00125-5, 2002.
Tokarczyk, R. and Moore, R.M.: Production of volatile organohalogens by
phytoplankton cultures. Geophys. Res. Lett., 21, 285-288, https://doi.org/10.1029/94GL00009, 1994.
Welshmeyer, N. A.: Fluorometric analysis of chlorophyll a in the presence of
chlorophyll b and pheopigments, Limnol. Oceanogr., 39, 1985–1992, https://doi.org/10.4319/lo.1994.39.8.1985, 1994.
World Meteorological Organization (WMO): Scientific assessment of ozone
depletion: 2010, Global Res. Monit. Proj. Rep. 52, Geneva, Switzerland, chapter 3, 2010.
Short summary
We conducted a shipboard observation over the Chukchi Sea and the Canada Basin
in the western Arctic Ocean to obtain vertical distributions of four volatile organic iodine compounds (VOIs) in seawater. High concentrations of four VOIs were found in the bottom layer water over the Chukchi Sea shelf, in which layer the concentration maximum of ammonium occurred simultaneously. We considered that the VOI production is associated with degradation of organic matter in the bottom sediment.
We conducted a shipboard observation over the Chukchi Sea and the Canada Basin
in the western...
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