News

Antioxidant responses of the mussel Mytilus coruscus co-exposed to ocean acidification, hypoxia and warming

Abstract.

"In the present study, the combined effects of pH, dissolved oxygen (DO) and temperature levels on the antioxidant responses of the mussel Mytilus coruscus were evaluated. Mussels were exposed to two pH (8.1, 7.7-acidification), two DO (6 mg L−1, 2 mg L−1-hypoxia) and two temperature levels[...]"

 

Source: Science Direct
Authors: Fahim Ullah Khan et al
DOI: https://doi.org/10.1016/j.marpolbul.2020.111869

Read the full article here.


Redox control on the tungsten isotope composition of seawater

Abstract.

"Free oxygen represents an essential basis for the evolution of complex life forms on a habitable Earth. The isotope composition of redox-sensitive trace elements such as tungsten (W) can possibly trace the earliest rise of oceanic oxygen in Earth’s history. However, the impact of redox changes on the W isotope composition of seawater is still unknown. Here, we report highly variable W isotope compositions in the water column of a redox-stratified basin (δ186/184W between +0.347 and +0.810 ‰) that contrast with the homogenous W isotope composition of the open ocean[...]"

 

Source: PNAS- Proceedings of the National Academy of Sciences of the United States of America
Authors: Florian Kurzweil et al.
DOI: https://doi.org/10.1073/pnas.2023544118

Read the full article here.


Seaweed farms provide refugia from ocean acidification

Abstract.

"Seaweed farming has been proposed as a strategy for adaptation to ocean acidification, but evidence is largely lacking. Changes of pH and carbon system parameters in surface waters of three seaweed farms along a latitudinal range in China were compared, on the weeks preceding harvesting, with those of the surrounding seawaters. Results confirmed that seaweed farming is efficient in buffering acidification, with Saccharina japonica showing the highest capacity of 0.10 pH increase within the aquaculture area[...]"

 

Source: Science Direct
Authors: Xi Xiao et al
DOI: https://doi.org/10.1016/j.scitotenv.2021.145192

Read the full article here.


Dissolved Organic Matter in the Upwelling System off Peru: Imprints of Bacterial Activity and Water Mass Characteristics

Abstract.

"Microbial degradation of dissolved organic matter (DOM) contributes to the formation and preservation of oxygen minimum zones (OMZs) in the ocean, but information on the spatial distribution and molecular composition of DOM in OMZ regions is scarce. We quantified molecular components of DOM that is, dissolved amino acids (DAA) and dissolved combined carbohydrates (DCCHO), in the upwelling region off Peru. We found the highest concentrations of DCCHO in fully oxygenated[...]"

 

Source: Advancing Earth and Space Science
Authors: Anja Engel et al.
DOI: https://doi.org/10.1029/2020JG006048

Read the full article here.


Photosensitized formation of sulfate and volatile sulfur gases from dissolved organic sulfur: Roles of pH, dissolved oxygen, and salinity

Abstract.

"The photodegradation of dissolved organic sulfur (DOS) is a potential source of aqueous sulfate and its chemical precursors in surface water. However, the photochemical fate of DOS and factors that control its fate still remain unclear. Herein, we employed a DOS model featuring a photosensitizer (humic acids, HA) to investigate the photochemical degradation pathways of DOS in various natural water sources, from which we observed the substantial photosensitized formation of sulfate, methanesulfonic acid (MSA), carbonyl [...]"

 

Source: Science Direct
Authors: Jian-Long Li et al.
DOI: https://doi.org/10.1016/j.scitotenv.2021.147449

Read the full article here.


Zooplankton grazing of microplastic can accelerate global loss of ocean oxygen

Abstract.

"Global warming has driven a loss of dissolved oxygen in the ocean in recent decades. We demonstrate the potential for an additional anthropogenic driver of deoxygenation, in which zooplankton consumption of microplastic reduces the grazing on primary producers. In regions where primary production is not limited by macronutrient availability, the reduction of grazing pressure on primary producers causes export production to increase. Consequently, organic particle remineralisation in[...]"

 

Source: Nature Communications 
Authors: K. Kvale et al.
DOI: https://doi.org/10.1038/s41467-021-22554-w

Read the full article here.


Gulf of Mexico blue hole harbors high levels of novel microbial lineages

Abstract.

"Exploration of oxygen-depleted marine environments has consistently revealed novel microbial taxa and metabolic capabilities that expand our understanding of microbial evolution and ecology. Marine blue holes are shallow karst formations characterized by low oxygen and high organic matter content. They are logistically challenging to sample, and thus our understanding of their biogeochemistry and microbial ecology is limited. We present a metagenomic and geochemical characterization of Amberjack Hole on the Florida continental shelf (Gulf of Mexico). Dissolved oxygen became depleted at the hole’s rim[...]"

 

Source: The ISME Journal 
Authors: N. V. Patin et al.
DOI: https://doi.org/10.1038/s41396-021-00917-x

Read the full article here.


Oceanographic processes control dissolved oxygen variability at a commercial Atlantic salmon farm: Application of a real-time sensor network

Abstract.

"Open ocean fish farming involves containment of cultured animals under environmental conditions influenced by seasonal variation and water quality. Recently, an important area of research focus has been on water quality monitoring to improve aquaculture management. The development of novel sensors that report in real-time is critical to improve the monitoring capacity of farms, while increasing the understanding of the dynamics of environmental variables. In this study, commercially available, real-time dissolved oxygen and temperature sensors were distributed in the center of 19 cages at a commercial[...]"

 

Source: Science Direct
Authors: Meredith Burke et al.
DOI: https://doi.org/10.1016/j.aquaculture.2020.736143

Read the full article here.


Phytoplankton, dissolved oxygen and nutrient patterns along a eutrophic river-estuary continuum: Observation and modeling

Abstract.

"Transport and fate of phytoplankton blooms and excessive nutrients along salinity and turbidity gradients of a river-estuary continuum could determine when and where impaired water quality occurs. However, the general spatiotemporal patterns, underlying mechanisms and their implication for water quality management are not well understood. This study reveals typical seasonal variations and longitudinal patterns of phytoplankton, dissolved oxygen (DO) and nutrients (C, N, and P) in the lower St. Johns River estuary in Florida based on 23 years of data and a model which spans 3 years. Evident declines in freshwater phytoplankton and DO concentrations were observed in the freshwater-saltwater transition zone[...]"

 

Source: Science Direct
Authors: Junna Wang et al.
DOI: https://doi.org/10.1016/j.jenvman.2020.110233

Read the full article here.


Imprint of Trace Dissolved Oxygen on Prokaryoplankton Community Structure in an Oxygen Minimum Zone

Abstract.

"The Eastern Tropical North Pacific (ETNP) is a large, persistent, and intensifying oxygen minimum zone (OMZ) that accounts for almost half of the total area of global OMZs. Within the OMZ core (∼350–700 m depth), dissolved oxygen is typically near or below the analytical detection limit of modern sensors (∼10 nM). Steep oxygen gradients above and below the OMZ core lead to vertical structuring of microbial communities that also vary between particle-associated (PA) and free-living (FL) size fractions. Here, we use 16S amplicon sequencing (iTags) to analyze the[...]"

Source: Frotiers in the Marine Science
Authors: Luis Medina Faull et al.
DOI: https://doi.org/10.3389/fmars.2020.00360

Read the full article here.


Showing 1 - 10 of 96 results.
Items per Page 10
of 10