Articles | Volume 13, issue 22
https://doi.org/10.5194/bg-13-6155-2016
© Author(s) 2016. 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-13-6155-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
22 Nov 2016
Research article |
| 22 Nov 2016
Seasonal variation of CaCO3 saturation state in bottom water of a biological hotspot in the Chukchi Sea, Arctic Ocean
Michiyo Yamamoto-Kawai
CORRESPONDING AUTHOR
Tokyo University of Marine Science and Technology, Tokyo, 108-8477,
Japan
Takahisa Mifune
Tokyo University of Marine Science and Technology, Tokyo, 108-8477,
Japan
Takashi Kikuchi
Japan Agency for Marine-Earth Science and Technology, Yokosuka,
237-0061, Japan
Shigeto Nishino
Japan Agency for Marine-Earth Science and Technology, Yokosuka,
237-0061, Japan
Related authors
Katsuro Katsumata, Shigeru Aoki, Kay I. Ohshima, and Michiyo Yamamoto-Kawai
EGUsphere, https://doi.org/10.5194/egusphere-2024-2237, https://doi.org/10.5194/egusphere-2024-2237, 2024
Short summary
Short summary
Ship-based observation provides data of such sea water properties as temperature, salinity, nutrients, and various gases, but some important world oceans have not still been covered. A voyage in 2019/20 in the southwest Indian Ocean along approximately 55° E from 30° S to the Antarctica attempted to fill one such data sparse regions. The measured cross section of the Antarctic Circumpolar Current and accompanying eddies demonstrates various oceanic behaviours including fronts and eddy mixing.
A. Kubo, M. Yamamoto-Kawai, and J. Kanda
Biogeosciences, 12, 269–279, https://doi.org/10.5194/bg-12-269-2015, https://doi.org/10.5194/bg-12-269-2015, 2015
K. E. Giesbrecht, L. A. Miller, M. Davelaar, S. Zimmermann, E. Carmack, W. K. Johnson, R. W. Macdonald, F. McLaughlin, A. Mucci, W. J. Williams, C. S. Wong, and M. Yamamoto-Kawai
Earth Syst. Sci. Data, 6, 91–104, https://doi.org/10.5194/essd-6-91-2014, https://doi.org/10.5194/essd-6-91-2014, 2014
Katsuro Katsumata, Shigeru Aoki, Kay I. Ohshima, and Michiyo Yamamoto-Kawai
EGUsphere, https://doi.org/10.5194/egusphere-2024-2237, https://doi.org/10.5194/egusphere-2024-2237, 2024
Short summary
Short summary
Ship-based observation provides data of such sea water properties as temperature, salinity, nutrients, and various gases, but some important world oceans have not still been covered. A voyage in 2019/20 in the southwest Indian Ocean along approximately 55° E from 30° S to the Antarctica attempted to fill one such data sparse regions. The measured cross section of the Antarctic Circumpolar Current and accompanying eddies demonstrates various oceanic behaviours including fronts and eddy mixing.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
A. Ooki, S. Kawasaki, K. Kuma, S. Nishino, and T. Kikuchi
Biogeosciences, 13, 133–145, https://doi.org/10.5194/bg-13-133-2016, https://doi.org/10.5194/bg-13-133-2016, 2016
Short summary
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.
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
Short summary
Short summary
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.
A. Kubo, M. Yamamoto-Kawai, and J. Kanda
Biogeosciences, 12, 269–279, https://doi.org/10.5194/bg-12-269-2015, https://doi.org/10.5194/bg-12-269-2015, 2015
K. E. Giesbrecht, L. A. Miller, M. Davelaar, S. Zimmermann, E. Carmack, W. K. Johnson, R. W. Macdonald, F. McLaughlin, A. Mucci, W. J. Williams, C. S. Wong, and M. Yamamoto-Kawai
Earth Syst. Sci. Data, 6, 91–104, https://doi.org/10.5194/essd-6-91-2014, https://doi.org/10.5194/essd-6-91-2014, 2014
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
Related subject area
Biogeochemistry: Coastal Ocean
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
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
Variable contribution of wastewater treatment plant effluents to downstream nitrous oxide concentrations and emissions
Long-term variations of pH in coastal waters along the Korean Peninsula
Responses of microbial metabolic rates to non-equilibrated silicate vs calcium-based ocean alkalinity enhancement
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
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)
Assessing the impacts of simulated Ocean Alkalinity Enhancement on viability and growth of near-shore species of phytoplankton
Seasonality and response of ocean acidification and hypoxia to major environmental anomalies in the southern Salish Sea, North America (2014–2018)
Countering the effect of ocean acidification in coastal sediments through carbonate mineral additions
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
Considerations for hypothetical carbon dioxide removal via alkalinity addition in the Amazon River watershed
High metabolism and periodic hypoxia associated with drifting macrophyte detritus in the shallow subtidal Baltic Sea
Production and accumulation of reef framework by calcifying corals and macroalgae on a remote Indian Ocean cay
Zooplankton community succession and trophic links during a mesocosm experiment in the coastal upwelling off Callao Bay (Peru)
Temporal and spatial evolution of bottom-water hypoxia in the St Lawrence estuarine system
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.
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.
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.
Yong-Woo Lee, Mi-Ok Park, Seong-Gil Kim, Tae-Hoon Kim, Yong-Hwa Oh, Sang Heun Lee, and Dong Joo Joung
EGUsphere, https://doi.org/10.5194/egusphere-2024-1836, https://doi.org/10.5194/egusphere-2024-1836, 2024
Short summary
Short summary
A 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 seaweeds aquaculture operations.
Laura Marin-Samper, Javier Arístegui, Nauzet Hernández-Hernández, and Ulf Riebesell
EGUsphere, https://doi.org/10.5194/egusphere-2024-1776, https://doi.org/10.5194/egusphere-2024-1776, 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 delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and its ecological implications
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.
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.
Jessica L. Oberlander, Mackenzie E. Burke, Cat A. London, and Hugh L. MacIntyre
EGUsphere, https://doi.org/10.5194/egusphere-2024-971, https://doi.org/10.5194/egusphere-2024-971, 2024
Short summary
Short summary
OAE is a promising negative emission technology that could restore the oceanic pH and carbonate system to a pre-industrial state. To our knowledge, this paper is the first to 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, near-shore environments.
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.
Kadir Bice, Tristen Myers, George Waldbusser, and Christof Meile
EGUsphere, https://doi.org/10.5194/egusphere-2024-796, https://doi.org/10.5194/egusphere-2024-796, 2024
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 its duration. We quantify the effect under different environmental conditions and assess the potential for increased atmospheric CO2 uptake.
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Cited articles
Alin, S. R., Feely, R. A., Dickson, A. G., Hernández-Ayón, J. M., Juranek, L. W., Ohman, M. D., and Goericke, R.: Robust empirical relationships for estimating the carbonate system in the southern California Current System and application to CalCOFI hydrographic cruise data (2005–2011), J. Geophys. Res., 117, C05033, https://doi.org/10.1029/2011JC007511, 2012.
Arrigo, K. R. and van Dijken, G. L.: Secular trends in Arctic Ocean net primary production, J. Geophys. Res., 116, C09011, https://doi.org/10.1029/2011JC007151, 2011.
Azetsu-Scott, K., Clarke, A., Falkner, K., Hamilton, J., Jones, E. P., Lee, C., Petrie, B., Prinsenberg, S., Starr, M., and Yeats, P.: Calcium carbonate saturation states in the waters of the Canadian Arctic Archipelago and the Labrador Sea, J. Geophys. Res., 115, C11021, https://doi.org/10.1029/2009JC005917, 2010.
Bates, N. R.: Assessing ocean acidification variability in the Pacific-Arctic region as part of the Russian-American Long-term Census of the Arctic, Oceanogr., 28, 36–45, 2015.
Bates, N. R., Mathis, J. T., and Cooper, L. W.: Ocean acidification and biologically induced seasonality of carbonate mineral saturation states in the western Arctic Ocean, J. Geophy. Res., 114, C11007, https://doi.org/10.1029/2008JC004862, 2009.
Bates, N. R., Orchowska, M. I., Garley, R., and Mathis, J. T.: Summertime calcium carbonate undersaturation in shelf waters of the western Arctic Ocean – how biological processes exacerbate the impact of ocean acidification, Biogeosciences, 10, 5281–5309, https://doi.org/10.5194/bg-10-5281-2013, 2013.
Blanchard, A. L., Parris, C. L., Knowlton, A. L., and Wade, N. R.: Benthic ecology of the northeastern Chukchi Sea, Part I. Environmental characteristics and macrofaunal community structure, 2008–2010, Cont. Shelf Res., 67, 52–66, 2013.
Branch, T. A., DeJoseph, B. M., Ray, L. J., and Wagner, C. A.: Impacts of ocean acidification on marine seafood, Trends Ecol. Evol., 28, 178–186, 2013.
Clough, L. M., Renaud, P. E., and Ambrose Jr., W. G.: Impacts of water depth, sediment pigment concentration, and benthic macrofaunal biomass on sediment oxygen demand in the western Arctic Ocean, Can. J. Fish. Aquat. Sci., 62, 1756–1765, 2005.
Cooper, L. W., Grebmeier, J. M., Larsen, I. L., Egorov, V. G., Theodorakis, C., Kelly, H. P., and Lovvorn, J. R.: Seasonal variation in sedimentation of organic materials in the St. Lawrence Island polynya region, Bering Sea, Mar. Ecol.-Prog. Ser., 226, 13–26, 2002.
Cross, J. N., Mathis, J. T., Bates, N. R., and Byrne, R. H.: Conservative and non-conservative variations of total alkalinity on the southeastern Bering Sea shelf, Mar. Chem., 154, 100–112, 2013.
Devol, A. H., Codispoti, L. A., and Christensen, J. P.: Summer and winter denitrification rates in western Arctic shelf sediments, Cont. Shelf Res., 17, 1029–1050, 1997.
Dickson, A. G.: Standard potential of the reaction: AgCl (s) + 1/2H2(g) = Ag(s) + HCl(aq), and the standard acidity constant of the ion HSO4− in synthetic sea water from 273.15 to 318.15 K, J. Chem. Thermodynam., 22, 113–127, 1990.
Dickson, A. G.: Determination of dissolved oxygen in sea water by Winkler titration, in: WOCE Operations Manual, Volume 3, Section 3.1, Part 3.1.3, WHP Operations and Methods, WHP Office Report WHPO 91-1, WOCE Report No. 68/91, Nov. 1994, Revision 1, Woods Hole, Mass., 13 pp., 1996.
Dickson, A. G. and Millero, F. J.: A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media, Deep-Sea Res., 34, 1733–1743, 1987.
Dickson, A. G., Sabine, C. L., and Christian, J. R.: Guide to best practices for ocean CO2 measurements, PICES Special Publications, 3, 191 pp., 2007.
Evans, W., Mathis, J. T., Winsor, P., Statscewich, H., and Whitledge, T. E.: A regression modeling approach for studying carbonate system variability in the Northern Gulf of Alaska, J. Geophys. Res., 118, 476–489, 2013.
Fabry, V. J., McClintock, J. B., Mathis, J. T., and Grebmeier, J. M.: Ocean acidification at high latitudes: the bellwether, Oceanogr., 22, 160–171, 2009.
Fujiwara, A., Hirawake, T., Suzuki, K., Eisner, L., Imai, I., Nishino, S., Kikuchi, T., and Saitoh, S.-I.: Influence of timing of sea ice retreat on phytoplankton size during marginal ice zone bloom period on the Chukchi and Bering shelves, Biogeosciences, 13, 115–131, https://doi.org/10.5194/bg-13-115-2016, 2016.
Gattuso, J. P. and Hansson, L.: Ocean acidification, Oxford University Press, 311 pp., 2011.
Grant, J., Hargrave, B., and MacPherson, P.: Sediment properties and benthic-pelagic coupling in the North Water, Deep-Sea Res. Pt. II, 49, 5259–5275, 2002.
Grebmeier, J. M.: Shifting patterns of life in the Pacific Arctic and Sub-Arctic seas, Mar. Sci., 4, 63–78, 2012.
Grebmeier. J. M. and McRoy, C. P.: Pelagic-benthic coupling on the shelf of the northern Bering and Chukchi Seas, III. Benthic food supply and carbon cycling, Mar. Ecol.-Prog. Ser., 53, 79–91, 1989.
Grebmeier, J. M., Cooper, L. W., Feder, H. M., and Sirenko, B. I.: Ecosystem dynamics of the Pacific-influenced Northern Bering and Chukchi Seas in the Amerasian Arctic, Prog. Oceanogr., 71, 331–361, 2006.
Grebmeier, J. M., Bluhm, B. A., Cooper, L. W., Denisenko, S. G., Iken, K., Kędra, M., and Serratos, C.: Time-series benthic community composition and biomass and associated environmental characteristics in the Chukchi Sea during the RUSALCA 2004–2012 Program, Oceanogr., 28, 116–133, 2015.
Green, M. A., Waldbusser, G. G., Reilly, S. L., Emerson, K., and O'Donnell, S.: Death by dissolution: sediment saturation state as a mortality factor for juvenile bivalves, Limnol. Oceanogr., 54, 1037–1047, 2009.
Gruber, N., Sarmiento, J. L., and Stocker, T. F.: An improved method for detecting anthropogenic CO2 in the oceans, Global Biogeochem. Cy., 10, 809–837, 1996.
Hirawake, T.: Cruise Report, Training Ship Oshoro Maru Cruise No. 255, Hokkaido University, Japan, 2013.
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, in: The GOSHIP Repeat Hydrography Manual: A Collection of Expert Reports and Guidelines, IOCCP Report Number 14, ICPO Publication Series Number 134, edited by: Hood, E. M., Sabine, C. L., and Sloyan, B. M., UNESCO-IOC, Paris, France, available at: www.go-ship.org/HydroMan.html (last access: 25 September 2015), 2010.
IPCC: Climate Change 2013: The Physical Science Basis, in: Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P. M., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp., https://doi.org/10.1017/CBO9781107415324, 2013.
Juranek, L. W., Feely, R. A., Peterson, W. T., Alin, S. R., Hales, B., Lee, K., Sabine, C. L., and Peterson, J.: A novel method for determination of aragonite saturation state on the continental shelf of central Oregon using multi-parameter relationships with hydrographic data, Geophys. Res. Lett., 36, L24601, https://doi.org/10.1029/2009GL040778, 2009.
Kikuchi, T.: R/V Mirai Cruise Report MR12-E03, JAMSTEC, Yokosuka, Japan, http://www.godac.jamstec.go.jp/darwin/e (last access: 21 September 2016), 2012.
Kroeker, K. J., Kordas, R., Crim, R., Hendriks, I. E., Ramajo, L., Singh, G. S., Duarte, C. M., and Gattuso, J. P.: Impacts of ocean acidification on marine organisms: quantifying sensitivities and interaction with warming, Glob. Change Biol., 19, 1884–1896, 2013.
Lee, S. H., Whitledge, T. E., and Kang, S. H.: Recent carbon and nitrogen uptake rates of phytoplankton in Bering Strait and the Chukchi Sea, Cont. Shelf Res., 27, 2231–2249, 2007.
Leinweber, A. and Gruber, N.: Variability and trends of ocean acidification in the Southern California Current System: A time series from Santa Monica Bay, J. Geophys. Res., 118, 3622–3633, 2013.
Lewis, E. and Wallace, D. W. R.: Program Developed for CO2 System Calculations, ORNL/CDIAC-105, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee, https://doi.org/10.3334/CDIAC/otg.CO2SYS_DOS_CDIAC105, 1998.
Li, Q., Wang, F., Wang, Z. A., Yuan, D., Dai, M., Chen, J., Dai, J., and Hoering, K. A.: Automated spectrophotometric analyzer for rapid single-point titration of seawater total alkalinity, Environ. Sci. Technol., 47, 11139–11146, 2013.
Lowry, K. E., van Dijken, G. L., and Arrigo, K. R.: Evidence of under-ice phytoplankton blooms in the Chukchi Sea from 1998 to 2012, Deep-Sea Res. Pt. II, 105, 105–117, 2014.
Mathis, J. T., Cross, J. N., Monacci, N., Feely, R. A., and Stabeno, P.: Evidence of prolonged aragonite undersaturations in the bottom waters of the southern Bering Sea shelf from autonomous sensors, Deep-Sea Res., 109, 125–133, 2014.
Mathis, J. T., Cross, J. N., Evans, W., and Doney, S. C.: Ocean acidification in the surface waters of the Pacific-Arctic boundary regions, Oceanogr., 28, 36–45, 2015.
Mehrbach, C., Culberson, C. H., Hawley, J. E., and Pytkowicz, R. M.: Measurement of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure, Limnol. Oceanogr., 18, 897–907, 1973.
Mathis, J. T. and Questel, J. M.: Assessing seasonal changes in carbonate parameters across small spatial gradients in the Northeastern Chukchi Sea, Cont. Shelf Res., 67, 42–51, 2013.
Millero, F. J.: Thermodynamics of the carbon dioxide system in the oceans, Geochim. Cosmochim. Ac., 59, 661–677, 1995.
Mucci, A.: The solubility of calcite and aragonite in seawater at various salinities, temperatures and atmosphere total pressure, Am. J. Sci., 238, 780–799, 1983.
Murata, A. and Takizawa, T.: Impact of a coccolithophorid bloom on the CO2 system in surface waters of the eastern Bering Sea shelf, Geophys. Res. Lett., 29, 1517, https://doi.org/10.1029/2001GL013906, 2002.
Nishino, S., Kikuchi, T., Fujiwara, A., Hirawake, T., and Aoyama, M.: Water mass characteristics and their temporal changes in a biological hotspot in the southern Chukchi Sea, Biogeosciences, 13, 2563–2578, https://doi.org/10.5194/bg-13-2563-2016, 2016.
Orr, J. X., Fabry, V. J., Aumont, O., Bopp, L., Doney, S. C., Feely, R. A., Gnanadesikan, A., Gruber, N., Ishida, A., Joos, F., Key,R. M., Lindsay, K., Maier-Reimer, E., Matear, R., Monfray, P., Mouchet, A., Najjar, R. G., Plattner, G.-K., Rodgers, K. B., Sabine, C. L., Sarmiento,J. L., Schlitzer, R., Slater, R. D., Totterdell, I. J., Weirig, M.-F., Yamanaka, Y., and Yool. A.: Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms, Nature, 437, 681–686, 2005.
Raven, J., Caldeira, K., Harry, E., Hoegh-Guldberg, O., Liss, P., Riebesell, U., Shepherd, J., Turley, C., and Watson, A.: Ocean acidification due to increasing atmospheric carbon dioxide, Report to The Royal Society, 68 pp., 2005.
Ries, J. B., Cohen, A. L., and McCorkle, D. C.: Marine calcifiers exhibit mixed responses to CO2-induced ocean acidification, Geology, 37, 1057–1152, 2009.
Rysgaard, S., Thamdrup, B., Risgaard-Petersen, N., Fossing, H., Berg, P., Christensen, P. B., and Dalsgaard, T.: Seasonal carbon and nutrient mineralization in a high-Arctic coastal marine sediment, Young Sound, Northeast Greenland, Mar. Ecol.-Prog. Ser., 175, 261–276, 1998.
Sabine, C. L., Key, R. M., Johnson, K. M., Millero, F. J., Poisson, A., Sarmiento, J. L., Wallace, D. W. R., and Winn, C. D.: Anthropogenic CO2 inventory of the Indian Ocean, Global Biogeochem. Cy., 13, 179–198, 1999.
Salisbury, J., Green, M., Hunt, C., and Campbell, J.: Coastal acidification by rivers: A new threat to shellfish, Eos Trans AGU, 89, 513–514, 2008.
Schlitzer, R.: Ocean Data View, http://odv.awi.de, 2015.
Springer, A. M. and McRoy, C. P.: The paradox of pelagic food webs in the northern Bering Sea-III, Patterns of primary production, Cont. Shelf Res., 13, 575–599, 1993.
Talmage, S. C. and Gobler, C. J.: The effects of elevated carbon dioxide concentrations on the metamorphosis, size, and survival of larval hard clams (Mercenaria mercenaria), bay scallops (Argopecten irradians), and Eastern oysters (Crassostrea virginica), Limnol. Oceanogr., 54, 2072–2080, 2009.
Wang, J., Cota, G. F., and Comiso, J. C.: Phytoplankton in the Beaufort and Chukchi Seas: distribution, dynamics, and environmental forcing, Deep-Sea Res. Pt. II, 52, 3355–3368, 2005.
Weingartner, T. J., Cavalieri, D. J., Aagaard, K., and Sasaki, Y.: Circulation, dense water formation, and outflow on the northeast Chukchi shelf, J. Geophys. Res., 103, 7647–7661, 1998.
Welch, H. E., Siferd, T. D., and Bruecker, P.: Marine zooplanktonic and benthic community respiration rates at Resolute, Canadian high Arctic, Can. J. Fish. Aquat. Sci., 54, 999–1005, 1997.
Wood, H. L., Spicer, J. I., and Widdicombe, S.: Ocean acidification may increase calcification rates, but at a cost, P. Roy. Soc. B, 275, 1767–1773, 2008.
Woodgate, R. A., Aagaard, K., and Weingartner, T. J.: Monthly temperature, salinity, and transport variability of the Bering Strait through flow, Geophys. Res. Lett., 32, L04601, https://doi.org/10.1029/2004GL021880, 2005.
Yamamoto-Kawai, M., Tanaka, N., and Pivovarov, S.: Freshwater and brine behaviors in the Arctic Ocean deduced from historical data of δ18O and alkalinity (1929–2002 AD), J. Geophys. Res., 110, C10003, https://doi.org/10.1029/2004JC002793, 2005.
Yamamoto-Kawai, M., McLaughlin, F. A., Carmack, E. C., Nishino, S., and Shimada, K.: Aragonite Undersaturation in the Arctic Ocean: effects of ocean acidification and sea ice melt, Science, 326, 1098–1100, 2009.
Yamamoto-Kawai, M., McLaughlin, F. A., and Carmack, E. C.: Effects of ocean acidification, warming and melting of sea ice on aragonite saturation of the Canada Basin surface water, Geophys. Res. Lett., 38, L03601, https://doi.org/10.1029/2010GL045501, 2011.
Yamamoto-Kawai, M., McLaughlin, F., and Carmack, E.: Ocean acidification in the three oceans surrounding northern North America, J. Geophys. Res., 118, 6274–6284, https://doi.org/10.1002/2013JC009157, 2013.
Yamamoto-Kawai, M., Kawamura, N., Ono, T., Kosugi, N., Kubo, A., Ishii, M., and Kanda, J.: Calcium carbonate saturation and ocean acidification in Tokyo Bay, Japan, J. Oceanogr., 71, 427–439, 2015.
Yao, W. and Byrne, R. H.: Simplified seawater alkalinity analysis: use of linear array spectrometers, Deep-Sea Res., 45, 1383–1392, 1998.
Yun, M. S., Whitledge, T. E., Kong, M., and Lee, S. H.: Low primary production in the Chukchi Sea shelf, 2009, Cont. Shelf Res., 76, 1–11, 2014.
Short summary
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.
Seasonal variation of Ω in bottom water in Hope Valley, a biological hotspot in the southern...
Altmetrics
Final-revised paper
Preprint