Article
Ecology
Mara Freilich, Alexandre Mignot, Glenn Flierl, Raffaele Ferrari
Summary: Recent observations have shown an increase in phytoplankton biomass in the North Atlantic during winter, attributed to a release from grazing pressure. Mathematical formulations of grazing as a function of phytoplankton concentration that are quadratic or decrease faster than linearly at low concentrations can reproduce the observed fall to spring transition in phytoplankton.
Article
Oceanography
Jeffrey W. Krause, Michael W. Lomas, Seth L. Danielson
Summary: The study investigated diatom productivity and phytoplankton grazing losses in the northern Bering and Chukchi seas. It found that diatom growth is influenced by nutrients, light, and their interaction, while protozoan grazing intensity is mainly affected by size.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2021)
Article
Environmental Sciences
Chi Hung Tang, Edward J. Buskey
Summary: Microzooplankton play a crucial role in connecting primary production and higher trophic levels in marine ecosystems. However, crude oil pollution can disrupt their grazing behavior and the relationship with phytoplankton, potentially leading to phytoplankton blooms.
MARINE POLLUTION BULLETIN
(2022)
Article
Oceanography
Michael R. Landry, Raleigh R. Hood, Claire H. Davies, Karen E. Selph, David Antoine, Mika C. Carl, Lynnath E. Beckley
Summary: This study investigated the plankton biomass structure, production, and grazing rates in the eastern Indian Ocean. The results showed that production and grazing rates increased significantly from south to north, with Prochlorococcus dominating productivity and microzooplankton accounting for most of the grazing. These findings are important for understanding the importance and changes in the marine ecosystem of the eastern Indian Ocean.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2022)
Article
Ecology
C. R. Asha Devi, K. G. Vimalkumar, K. B. Padmakumar, C. T. Lathika, T. P. Maneesh, M. Sudhakar
Summary: The study explored the role of microzooplankton in mediating the microbial food web in bloom waters of Noctiluca scintillans. It found that during the bloom period, microzooplankton played a significant role in sustaining high secondary production, particularly through top-down controls on ciliates.
REGIONAL STUDIES IN MARINE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Guilherme Duarte Ferreira, Filomena Romano, Nikola Medic, Paraskevi Pitta, Per Juel Hansen, Kevin J. Flynn, Aditee Mitra, Albert Calbet
Summary: Mixoplankton impact grazing rate estimation, chlorophyll and cell counts are not sufficient, whole community approaches mimic reality better.
SCIENTIFIC REPORTS
(2021)
Review
Oceanography
Maria Vernet, Ingrid Ellingsen, Christian Marchese, Simon Belanger, Mattias Cape, Dag Slagstad, A. Patricia Matrai
Summary: The study provides an overview of annual net primary production rates around Greenland over the last decade, with a focus on spring bloom initiation. The results show a strong south-north gradient in productivity rates, with higher rates observed in regions influenced by North Atlantic water and lower rates in the Arctic Ocean.
PROGRESS IN OCEANOGRAPHY
(2021)
Article
Environmental Sciences
Yujian Wen, Guodong Zhang, Yuyao Song, Guicheng Zhang, Jun Sun
Summary: The dilution experiment technique was employed in two cruises conducted in July-August and October-November 2020, with 14 stations in total. The study comprehensively investigates the grazing impact of microzooplankton on phytoplankton in the interior of Bohai Bay. Spatially and seasonally, both the microzooplankton grazing rates (m) and phytoplankton growth rates (& mu;(0)) were significantly higher in summer compared to autumn, and the growth rate of phytoplankton was positively correlated with temperature. The ratio of microzooplankton grazing rate to phytoplankton growth rate (m/& mu;(0)) showed no significant spatial and seasonal differences, indicating a consistent daily consumption of primary production by microzooplankton in the two seasons. Therefore, the research highlights a close coupling between microzooplankton grazing and phytoplankton growth in the Bohai Bay.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Ecology
Marco J. Cabrerizo, Emilio Maranon
Summary: The study found that the highest grazing rates align with the highest growth rates, corresponding to medium cell sizes. There were no significant differences in growth or grazing between the smallest and largest cell sizes considered. The grazing-to-growth ratio was largely independent of cell size and C:N ratios, with low thermal dependence.
Article
Geochemistry & Geophysics
Shuo Zhang, Donald J. DePaolo, Renjie Zhou, Yuefei Huang, Guangqian Wang
Summary: Predicting mineral-fluid reaction rates in geologic materials is highly uncertain, despite their importance in various applications. The slow calcite-fluid reaction in deep sea carbonate sediments remains poorly understood, as well as the persistence of non-zero rates over millions of years. This study examines pore fluid data from ocean drilling archives to estimate the rates of calcite dissolution and precipitation as a function of depth and sediment age.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Anna L. Harrison, Jacques Schott, Eric H. Oelkers, Katharine Maher, Vasileios Mavromatis
Summary: The isotopic composition of carbonate minerals provides a record of historical geochemical and environmental conditions. This study found that rapid exchange of C and O isotopes can occur within a short time under chemical equilibrium conditions in calcite. However, the long-term persistence of this process at geological time scales is difficult to predict.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geography, Physical
Tobias Reiner Vonnahme, Emma Persson, Ulrike Dietrich, Eva Hejdukova, Christine Dybwad, Josef Elster, Melissa Chierici, Rolf Gradinger
Summary: The study found evidence of subglacial discharge and upwelling in a fast-ice covered Svalbard fjord, with a substantial impact on the fjord ecosystem and primary production. Despite lower estimated bottom-water entrainment factor and total fluxes compared to summer studies, there was still a significant increase in phytoplankton primary productivity. The combination of stratified surface water layer, higher under-ice irradiance, and nutrient concentrations at the glacier front supported much higher phytoplankton production compared to a marine reference site at the fast-ice edge.
Article
Geochemistry & Geophysics
Priyanka Agrawal, Till Bollermann, Amir Raoof, Oleg Iliev, Cornelius Fischer, Mariette Wolthers
Summary: This study used numerical simulations to investigate the dissolution processes of nano- and micron-scale rough calcite surfaces and found that incorporating rate spectra in the model is essential for matching simulated and measured rate spectra. Experimental results suggest that chemical heterogeneity, surface topography, and the resulting heterogeneity in the free energy landscape play a major role in controlling dissolution rate spectra. Furthermore, injecting more acidic solutions at higher velocities led to an increase in hydrodynamics-induced rate variability at microscopically rough surfaces.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geography, Physical
Pallavi Choudhari, Abhilash Nair, Rahul Mohan, Shramik Patil
Summary: Changes in ocean alkalinity affect the concentration of pCO2 in the atmosphere, with higher alkalinity resulting in lower pCO2 levels. This study examines the factors influencing the burial of coccoliths in subantarctic sediments and the surface ocean changes in the subtropical South Indian Ocean. The findings suggest that reduced coccolith production during the glacial period can be attributed to competition from diatoms and dilution by biogenic silica. Additionally, the decline in glacial coccolith concentration is explained by reduced carbonate burial due to low carbonate saturation in the deep water. The study highlights the importance of coccolith production and deep ocean carbonate saturation in determining their burial in subantarctic sediments over the past 41,500 years. Furthermore, the study region also records changes in the Agulhas Return Current through variations in the proportion of tropical-subtropical coccolith assemblages.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Review
Oceanography
Siyu Jiang, Fuminori Hashihama, Yukio Masumoto, Hongbin Liu, Hiroshi Ogawa, Hiroaki Saito
Summary: This study measured surface phytoplankton growth and mortality rates using dilution experiments and sensitive nutrient analysis in the Eastern Indian Ocean, demonstrating that the region is not a stable oligotrophic marine ecosystem but dynamic, influenced by unique regional physical events.
PROGRESS IN OCEANOGRAPHY
(2022)
Article
Environmental Sciences
Jennifer L. Williamson, Andrew Tye, Dan J. Lapworth, Don Monteith, Richard Sanders, Daniel J. Mayor, Chris Barry, Mike Bowes, Michael Bowes, Annette Burden, Nathan Callaghan, Gareth Farr, Stacey Felgate, Alice Fitch, Stuart Gibb, Pete Gilbert, Geoff Hargreaves, Patrick Keenan, Vassilis Kitidis, Monika Juergens, Adrian Martin, Ian Mounteney, Philip D. Nightingale, M. Gloria Pereira, Justyna Olszewska, Amy Pickard, Andrew P. Rees, Bryan Spears, Mark Stinchcombe, Debbie White, Peter Williams, Fred Worrall, Chris Evans
Summary: This study provides a comprehensive assessment of riverine dissolved organic carbon (DOC) export in Great Britain, revealing that smaller river systems draining peat-rich areas are underestimated in global syntheses. The study also highlights the significant influence of upland conifer plantation forestry on the spatial distribution of DOC exports. These findings have implications for future assessments of CO2 sequestration potential and climate change mitigation strategies.
Article
Environmental Sciences
Ruth L. Airs, Rachael Beale, Luca Polimene, Yin Chen, Michaela A. Mausz, David J. Scanlan, Claire E. Widdicombe, Glen A. Tarran, E. Malcolm S. Woodward, Carolyn Harris, Andrea McEvoy
Summary: Glycine betaine (GBT) is a nitrogenous osmolyte found throughout the marine environment. This study presents a seasonal dataset of GBT concentrations in marine suspended particulate material, showing peaks in summer and autumn. The GBT concentrations are associated with specific phytoplankton groups or species, suggesting different environmental drivers for different periods of the GBT seasonality.
Correction
Environmental Sciences
Ruth L. Airs, Rachael Beale, Luca Polimene, Yin Chen, Michaela A. Mausz, David J. Scanlan, Claire E. Widdicombe, Glen A. Tarran, E. Malcolm S. Woodward, Carolyn Harris, Andrea McEvoy
Article
Environmental Sciences
Helge A. A. Winkelbauer, Babette A. A. Hoogakker, Rosie J. J. Chance, Catherine V. V. Davis, Christopher J. J. Anthony, Juliane Bischoff, Lucy J. J. Carpenter, Simon R. N. Chenery, Elliott M. M. Hamilton, Philip Holdship, Victoria L. L. Peck, Alex J. J. Poulton, Mark C. C. Stinchcombe, Karen F. F. Wishner
Summary: Planktic foraminifera test iodine to calcium ratios are a useful proxy method for assessing subsurface seawater oxygenation states. Lower I/Ca ratios have been observed in planktic foraminifera from locations with oxygen depleted subsurface waters. This is because only oxidized iodine species, such as iodate, are incorporated into foraminiferal calcite. However, planktic foraminifera from well oxygenated regions have significantly lower I/Ca ratios compared to similarly well-oxygenated core-top samples, suggesting post-mortem iodine uptake during settling or burial.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Thomas R. Anderson, Wendy C. Gentleman, B. B. Cael, Joel J. -M. Hirschi, Robert L. Eastwood, Daniel J. Mayor
Summary: Sinking detritus particles play a crucial role in regulating global climate by transporting organic carbon into the deep ocean. We propose a new model that shows how the surface area of these particles increases during degradation, leading to faster remineralisation rates and reduced carbon sequestration. Our findings highlight the importance of further research to better understand the dynamics of particle surface area and microbial activity in order to improve global biogeochemical models.
Article
Oceanography
Aimee Coggins, Andrew J. Watson, Ute Schuster, Neill Mackay, Brian King, Elaine McDonagh, Alex J. Poulton
Summary: Using biogeochemical Argo floats, we studied the dissolved inorganic carbon (DIC) concentrations and fluxes of a mesoscale diatom bloom in the Southern Ocean. The methodology for deriving surface pCO2 from float-based pH and oxygen measurements was independently analyzed and validated. The results showed good agreement between float and ship measurements, supporting the use of biogeochemical Argo floats to supplement shipboard pCO2 measurements. The study also calculated a significant CO2 flux from the atmosphere into the surface mixed layer, driven by air-sea pCO2 gradient and variable winds.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2023)
Article
Oceanography
Joanna Ainsworth, Alex J. Poulton, Maeve C. Lohan, Mark C. Stinchcombe, Alastair J. M. Lough, Mark Moore
Summary: The Southern Ocean is a large HNLC region where iron limits phytoplankton growth and productivity. Island wakes can mix iron into surface waters, leading to large phytoplankton blooms. The interaction between iron and phytoplankton is reciprocal in blooms, with plankton regulating the cycling of iron. Observations and experiments were conducted to investigate iron limitation and remineralization in a November 2017 bloom downstream of South Georgia. The results showed that surface phytoplankton were iron limited, and iron remineralization mainly occurred through rapid release of adsorbed iron.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2023)
Article
Limnology
Chris D. Evans, Stacey L. Felgate, Steffi Carter, Mark Stinchcombe, Edward Mawji, Andrew P. Rees, Inma Lebron, Richard Sanders, Paul Brickle, Daniel J. Mayor
Summary: The interface between freshwater and marine systems, estuaries, can act as a filter of the land-ocean carbon flux, removing terrestrially derived dissolved organic carbon (DOC). However, the fate of peat-derived DOC within estuaries remains poorly understood due to various factors. The study of DOC and inorganic nutrients in minimally disturbed Falkland Island estuaries revealed limited evidence of estuarine DOC removal, but observed hot zones of biogeochemical activity and in situ DOC production. This suggests that estuaries receiving high organic matter inputs can serve as analogues for natural biogeochemical functioning in temperate estuaries.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Chemistry, Multidisciplinary
Rhiannon L. Jones, Michael P. Meredith, Maeve C. Lohan, E. Malcolm S. Woodward, Katrien Van Landeghem, Kate Retallick, Oliver Flanagan, Mehul Vora, Amber L. Annett
Summary: Continued atmospheric and oceanic warming at the West Antarctic Peninsula (WAP) is causing significant changes to glaciers and the marine environment. Two bays along the WAP were compared during austral summer 2020 to study sediment sources and drivers of macronutrient distributions. The study found that land-terminating glaciers have a meltwater-rich surface layer with strong vertical mixing, while marine-terminating glaciers drive vigorous mixing of sediment and entrainment of macronutrient deep waters. This shift to land-terminating glaciers may have a significant impact on nutrient and sediment supply to the euphotic zone, affecting primary productivity and carbon uptake efficiency.
Article
Chemistry, Multidisciplinary
Xue-Gang Chen, Dagmara Rusiecka, Martha Gledhill, Angela Milne, Amber L. Annett, Antony J. Birchill, Maeve C. Lohan, Simon Ussher, E. Malcolm S. Woodward, Eric P. Achterberg
Summary: This article reports on the seasonal distributions of dissolved zinc, nickel, copper, cadmium, aluminum, and nutrients on the Northeast Atlantic continental margin. The variations in surface water trace metals and nutrient concentrations were mainly regulated by seasonal changes in biological processes. The stoichiometry of trace metals and nutrients on the continental shelf was additionally affected by fluvial inputs.
Article
Environmental Sciences
E. Elena Garcia-Martin, Richard Sanders, Chris D. Evans, Vassilis Kitidis, Dan J. Lapworth, Bryan M. Spears, Andy Tye, Jennifer L. Williamson, Chris Balfour, Mike Best, Michael Bowes, Sarah Breimann, Ian J. Brown, Annette Burden, Nathan Callaghan, Nancy B. Dise, Gareth Farr, Stacey L. Felgate, James Fishwick, Mike Fraser, Stuart Gibb, Pete J. Gilbert, Nina Godsell, Africa P. Gomez-Castillo, Geoff Hargreaves, Carolyn Harris, Oban Jones, Paul Kennedy, Anna Lichtschlag, Adrian P. Martin, Rebecca May, Edward Mawji, Ian Mounteney, Philip D. Nightingale, Justyna P. Olszewska, Stuart C. Painter, Christopher R. Pearce, M. Gloria Pereira, Kate Peel, Amy Pickard, John A. Stephens, Mark Stinchcombe, Barry Thornton, E. Malcolm S. Woodward, Deborah Yarrow, Daniel J. Mayor
Summary: The concentrations of particulate organic carbon (POC) and particulate organic nitrogen (PON) were evaluated in 13 British estuaries, and their sources were assessed using stable carbon and nitrogen isotopes. The results showed a high variability in POC and PON concentrations within the estuaries, indicating inputs and losses of organic material. The land cover of the catchment area appeared to influence the contribution of POC to the total organic carbon flux from the estuary to coastal waters.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Environmental Sciences
J. E. Hatton, H. C. Ng, L. Meire, E. M. S. Woodward, M. J. Leng, C. D. Coath, A. Stuart-Lee, T. Wang, A. L. Annett, K. R. Hendry
Summary: Glaciers and ice sheets are rapidly warming due to climate change, and research suggests that glacial meltwaters provide important nutrients to downstream ecosystems. However, the fate of these nutrients in fjord environments is still uncertain. A study in southwest Greenland used concentration data and isotopic compositions to investigate silicon cycling in two contrasting fjords. The results suggest that glacially derived amorphous silica may play a role in modifying coastal waters within fjords.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Environmental Sciences
Wenhao Wang, Heather Goring-Harford, Korinna Kunde, E. Malcolm S. Woodward, Maeve C. Lohan, Douglas P. Connelly, Rachael H. James
Summary: Chromium isotopic composition in ancient marine sediments can be used to infer changes in past seawater oxygenation or biological productivity. The relative contribution of external sources and internal cycling on the distribution of dissolved chromium in the oceans is still debated. In this study, water column profiles were obtained for dissolved chromium concentrations and chromium isotopes in the sub-tropical North Atlantic. The results suggest that benthic inputs and the formation of colloid aggregates of Fe-(oxyhydr)oxides play important roles in shaping the distribution of chromium.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Engineering, Marine
Rowena Stern, Kathryn Picard, Jessica Clarke, Charlotte E. Walker, Claudia Martins, Clare Marshall, Ana Amorim, E. Malcolm S. Woodward, Claire Widdicombe, Glen Tarran, Martin Edwards
Summary: This study evaluates the value of genetic methods in plankton monitoring and reveals that genetic methods can detect some special plankton communities that cannot be found by microscopic methods. Most of these detected plankton are mixotrophic or heterotrophic. In addition, quantitative real-time PCR detection reveals the growth pattern of two potentially harmful plankton species.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Oceanography
Kathryn B. Cook, Anna Belcher, Daniel Bondyale Juez, Gabriele Stowasser, Sophie Fielding, Ryan A. Saunders, Mohamed A. Elsafi, George A. Wolff, Sabena J. Blackbird, Geraint A. Tarling, Daniel J. Mayor
Summary: Zooplankton play an important role in ocean biogeochemistry, and their role in controlling atmospheric CO2 concentrations needs to be better understood. Pelagic mesozooplankton and micronekton communities influence the fate of organic matter through various ways, including consumption of primary producers and the active flux of carbon through diel vertical migration (DVM). The study provides insight into the biomass and metabolic budgets of mesopelagic animals, highlighting the need for a better understanding of lipid-storing animals and their influence on carbon budgeting in the pelagic.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2023)