Ronnie N. Glud

Seasonal dynamics of autotrophic and heterotrophic plankton metabolism and P_CO2 in a subarctic Greenland fjord

Publisher: Wiley

Date: 30-08-2014

DOI: 10.4319/LO.2014.59.5.1764

Pore water conditions driving calcium carbonate dissolution in reef sands

Publisher: Elsevier BV

Date: 06-2020

DOI: 10.1016/J.GCA.2020.04.001

New Training to Meet the Global Phosphorus Challenge.

Publisher: American Chemical Society (ACS)

Date: 08-07-2019

DOI: 10.1021/ACS.EST.9B03519

Depression chains in seafloor of contrasting morphology, Atacama Trench margin: a comment on Marshet al.(2018)

Publisher: The Royal Society

Date: 03-2019

DOI: 10.1098/RSOS.182053

Abstract: This comment presents acoustic and visual data showing deep seafloor depression chains similar to those reported in Marsh et al. ( R. Soc. open sci. 5: 180286), though from a different deep-sea setting. Marsh et al. present data collected during cruise JC120 from polymetallic nodule rich sites within the Clarion-Clipperton Fracture Zone (CCFZ), at water depths of between 3999 and 4258 m. Within this comment, we present data collected with equivalent acoustic and imaging devices on-board the RV Sonne (SO261—March/April 2018) from the Atacama Trench, approximately 4000 m depth, which shows comparable depression chains in the seafloor. In contrast with the CCFZ observations, our study area was wholly free of polymetallic nodules, an observation therefore weakening the ‘ballast collection’ by deep-sea ing mammals formation hypothesis discussed in their paper . We support their alternate hypothesis that if these features are indeed generated by deep- ing megafauna, then they are more likely the resultant traces of infauna feeding or marks made during opportunistic capture of benthic fish/cephalopods. We observed these potential prey fauna with lander and towed camera systems during the cruise, with ex le images of these presented here. Both the SO261 and JC120 cruises employed high-resolution sidescan systems at deployment altitudes seldom used routinely until the last few years during scientific deep-sea surveys. Given that both cruises found these depression chains in contrasting physical regions of the East Pacific, they may have a more ubiquitous distribution than at just these sites. Thus, the impacts of cetacean foraging behaviour on deep seafloor communities, and the potential relevance of these prey sources to deep- ing species, should be considered.

Behavioural patterns of the soft-shell clam Mya arenaria: implications for benthic oxygen and nitrogen dynamics

Publisher: Inter-Research Science Center

Date: 18-07-2019

DOI: 10.3354/MEPS13004

Metabolism in anoxic permeable sediments is dominated by eukaryotic dark fermentation

Publisher: Springer Science and Business Media LLC

Date: 28-11-2017

DOI: 10.1038/NGEO2843

Effects of cattle slurry and nitrification inhibitor application on spatial soil O2 dynamics and N2O production pathways

Publisher: Elsevier BV

Date: 11-2017

DOI: 10.1016/J.SOILBIO.2017.07.012

Eurythenes atacamensis sp. nov. (Crustacea: Amphipoda) exhibits ontogenetic vertical stratification across abyssal and hadal depths in the Atacama Trench, eastern South Pacific Ocean

Publisher: Springer Science and Business Media LLC

Date: 14-05-2021

DOI: 10.1007/S12526-021-01182-Z

Abstract: Eurythenes S.I. Smith in Scudder, 1882 (Crustacea: Amphipoda) are prevalent scavengers of the benthopelagic community from bathyal to hadal depths. While a well-studied genus, molecular systematic studies have uncovered cryptic speciation and multiple undescribed lineages. Here, we apply an integrative taxonomic approach and describe the tenth species, Eurythenes atacamensis sp. nov., based on specimens from the 2018 Atacamex and RV Sonne SO261 Expeditions to the southern sector of the Peru-Chile Trench, the Atacama Trench (24–⁠21°S). Eurythenes atacamensis sp. nov. is a large species, max. observed length 83.2 mm, possesses diagnostic features, including a short gnathopod 1 palm and a chelate gnathopod 2 palm, and a distinct genetic lineage based on a 16S rRNA and COI phylogeny. This species is a dominant bait-attending fauna with an extensive bathymetric range, spanning from 4974 to 8081 m. The RV Sonne SO261 specimens were recovered along a 10-station transect from abyssal to hadal depths and further examined for demographic and bathymetric-related patterns. Ontogenetic vertical stratification was evident across the trench axis, with only juveniles present at abyssal depths (4974–6025 m). Total length-depth analysis revealed that the size of females was unrelated to depth, whereas juveniles followed a sigmoidal relationship with a step-up in size at depths m. Thus, these bathymetric trends suggest that juveniles and females employ differing ecological strategies in subduction trench environments. This study highlights that even dominant and ecologically important species are still being discovered within the abyssal and hadal environments. Continued systematic expeditions will lead to an improved understanding of the eco-evolutionary drivers of speciation in the world’s largest ecosystem.

Resolving community metabolism of eelgrass Zostera marina meadows by benthic flume-chambers and eddy covariance in dynamic coastal environments

Publisher: Inter-Research Science Center

Date: 04-03-2021

DOI: 10.3354/MEPS13616

Abstract: Sediment resuspension is a common process in dynamic coastal settings, but its implications for remineralization and carbon turnover in seagrass meadows are poorly understood. Here, we assessed eelgrass Zostera marina metabolism in the Baltic Sea (SW Finland) using benthic flume-chambers and aquatic eddy covariance to critically evaluate the drivers of benthic O 2 exchange during dynamic flow conditions. During quiescent weather conditions, the 2 methods resolved similar metabolic rates and net ecosystem autotrophy (±11% of each other). However, elevated flow speeds and sediment resuspension halfway through the study induced a 5-fold increase in the O 2 uptake rates measured by eddy covariance, whereas chamber fluxes remained relatively unchanged. Following particle resettlement, instruments were redeployed and the benthic O 2 uptake resolved by both techniques was just ~30% of the values measured before resuspension. Laboratory investigations revealed sediment resuspension could potentially increase benthic O 2 uptake up to 6fold, mainly due to the reoxidation of reduced compounds (e.g. FeS x ). This process was fully captured by the eddy O 2 fluxes, but not by the chamber incubation. Consequently, the chamber and eddy net ecosystem metabolism amounted to -17 and -824 mmol C m -2 , respectively, throughout the study period. The rapid reoxidation and long-term effects of resuspension on benthic O 2 dynamics highlight the importance of fully capturing dynamic conditions when assessing the overall carbon turnover in coastal habitats. Future studies on the biogeochemical functioning of coastal environments should aim to capture the natural frequency and duration of resuspension events.

Benthic Carbon Mineralization and Nutrient Turnover in a Scottish Sea Loch: An Integrative In Situ Study

Publisher: Springer Science and Business Media LLC

Date: 08-09-2016

DOI: 10.1007/S10498-016-9300-8

Transport Zonation Limits Coupled Nitrification-Denitrification in Permeable Sediments

Publisher: American Chemical Society (ACS)

Date: 21-11-2013

DOI: 10.1021/ES403318X

Abstract: Measurement of biogeochemical processes in permeable sediments (including the hyporheic zone) is difficult because of complex multidimensional advective transport. This is especially the case for nitrogen cycling, which involves several coupled redox-sensitive reactions. To provide detailed insight into the coupling between ammonification, nitrification and denitrification in stationary sand ripples, we combined the diffusion equilibrium thin layer (DET) gel technique with a computational reactive transport biogeochemical model. The former approach provided high-resolution two-dimensional distributions of NO3(-) and (15)N-N2 gas. The measured two-dimensional profiles correlate with computational model simulations, showing a deep pool of N2 gas forming, and being advected to the surface below ripple peaks. Further isotope pairing calculations on these data indicate that coupled nitrification-denitrification is severely limited in permeable sediments because the flow and transport field limits interaction between oxic and anoxic pore water. The approach allowed for new detailed insight into subsurface denitrification zones in complex permeable sediments.

Independent radiation of snailfishes into the hadal zone confirmed by Paraliparis selti sp. nov. (Perciformes: Liparidae) from the Atacama Trench, SE Pacific

Publisher: Springer Science and Business Media LLC

Date: 10-2022

DOI: 10.1007/S12526-022-01294-0

Abstract: Snailfishes are among the most rapidly radiating families of marine fishes, resulting in a global distribution from the coastal intertidal to deep subduction trenches. The true ersity and distribution of deep-water snailfishes, particularly at hadal depths ( m) and in the Southern Hemisphere, remain uncertain due to the rarity of s les. Here, we present the snailfish ersity at near-hadal and hadal depths in the Atacama Trench, which runs along the southwest coast of South America. Using free-fall baited cameras and traps, we documented at least three species of hadal snailfishes between 5920 and 7608 m based on distinct morphologies. One snailfish specimen was recovered from 6714 m, which we describe herein as Paraliparis selti sp. nov., based on a combined morphological and molecular taxonomic approach (16S, COI, and Cyt-b). Paraliparis selti sp. nov. is morphologically distinct from described snailfishes due to a combination of high number of vertebrae (65) particularly the abdominal vertebrae (12), dorsal fin rays (60), anal fin rays (52), and caudal fin rays (8) comparatively low number of pectoral fin rays (18) which forms a deep notch with two widely spaced non-rudimentary rays. Micro-CT was used to minimise dissection of the specimen and to provide a digital holotype. Paraliparis selti sp. nov. highlights the importance of the Liparidae at hadal depths and provides evidence for at least two independent radiations of snailfishes into the hadal zone.

The transformation and fate of sub‐Arctic microphytobenthos carbon revealed through ¹³ C‐labeling

Publisher: Wiley

Date: 23-08-2016

DOI: 10.1002/LNO.10377

The climate benefit of seagrass blue carbon is reduced by methane fluxes and enhanced by nitrous oxide fluxes

Publisher: Springer Science and Business Media LLC

Date: 13-10-2023

DOI: 10.1038/S43247-023-01022-X

Correction to Transport Zonation Limits Coupled Nitrification-Denitrification in Permeable Sediments

Publisher: American Chemical Society (ACS)

Date: 22-05-2014

DOI: 10.1021/ES502359A

Pulses of labile carbon cause transient decoupling of fermentation and respiration in permeable sediments

Publisher: Wiley

Date: 31-07-2023

DOI: 10.1002/LNO.12411

Abstract: Dihydrogen (H 2 ) is an important intermediate in anaerobic microbial processes, and concentrations are tightly controlled by thermodynamic limits of consumption and production. However, recent studies reported unusual H 2 accumulation in permeable marine sediments under anoxic conditions, suggesting decoupling of fermentation and sulfate reduction, the dominant respiratory process in anoxic permeable marine sediments. Yet, the extent, prevalence and potential triggers for such H 2 accumulation and decoupling remain unknown. We surveyed H 2 concentrations in situ at different settings of permeable sand and found that H 2 accumulation was only observed during a coral spawning event on the Great Barrier Reef. A flume experiment with organic matter addition to the water column showed a rapid accumulation of hydrogen within the sediment. Laboratory experiments were used to explore the effect of oxygen exposure, physical disturbance and organic matter inputs on H 2 accumulation. Oxygen exposure had little effect on H 2 accumulation in permeable sediments suggesting both fermenters and sulfate reducers survive and rapidly resume activity after exposure to oxygen. Mild physical disturbance mimicking sediment resuspension had little effect on H 2 accumulation however, vigorous shaking led to a transient accumulation of H 2 and release of dissolved organic carbon suggesting mechanical disturbance and cell destruction led to organic matter release and transient decoupling of fermenters and sulfate reducers. In summary, the highly dynamic nature of permeable sediments and its microbial community allows for rapid but transient decoupling of fermentation and respiration after a C pulse, leading to high H 2 levels in the sediment.

Diel coral reef acidification driven by porewater advection in permeable carbonate sands, Heron Island, Great Barrier Reef

Publisher: American Geophysical Union (AGU)

Date: 02-2011

DOI: 10.1029/2010GL046053

Cable bacteria promote DNRA through iron sulfide dissolution

Publisher: Wiley

Date: 14-12-2018

DOI: 10.1002/LNO.11110

Sediment Accumulation and Carbon Burial in Four Hadal Trench Systems

Publisher: Wiley

Date: 25-01-2022

DOI: 10.1002/ESSOAR.10510267.1

The isotope effect of denitrification in permeable sediments

Publisher: Elsevier BV

Date: 05-2014

DOI: 10.1016/J.GCA.2014.02.029

Bacterial and viral dynamics during a mass coral spawning period on the Great Barrier Reef

Publisher: Inter-Research Science Center

Date: 26-03-2008

DOI: 10.3354/AME01179

Quantifying denitrification in rippled permeable sands through combined flume experiments and modeling

Publisher: Wiley

Date: 07-2012

DOI: 10.4319/LO.2012.57.4.1217

The kinetics of denitrification in permeable sediments

Publisher: Springer Science and Business Media LLC

Date: 09-09-2012

DOI: 10.1007/S10533-012-9789-X

K – Goldschmidt Abstracts 2013

Publisher: Mineralogical Society

Date: 07-2013

DOI: 10.1180/MINMAG.2013.077.5.11

SDU

Location: Denmark

View Organisation

Discovery Projects - Grant ID: DP1096457

Start Date: 07-2010

End Date: 06-2013

Amount: $180,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP110103638

Start Date: 2011

End Date: 12-2014

Amount: $310,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0878683

Start Date: 07-2008

End Date: 12-2011

Amount: $340,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP160100248

Start Date: 2016

End Date: 12-2020

Amount: $305,300.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP150101281

Start Date: 06-2015

End Date: 06-2018

Amount: $339,100.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP180101762

Start Date: 02-2018

End Date: 12-2020

Amount: $411,665.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP110100040

Start Date: 01-2011

End Date: 12-2014

Amount: $284,000.00

Funder: Australian Research Council