Abstract. 

"It is commonly known that phytoplankton have a pivotal role in marine biogeochemistry and ecosystems as carbon fixers and oxygen producers, but their response to deoxygenation has scarcely been studied. Nonetheless, in the major oceanic oxygen minimum zones (OMZs), all surface phytoplankton groups, regardless of size, disappear and are replaced by unique cyanobacteria lineages below the oxycline. To develop reasonable hypotheses to explain this pattern, we conduct a review of available information on OMZ phytoplankton, and we re-analyze previously published data (flow cytometric and hydrographic) on vertical structure of phytoplankton communities in relation to light and O₂ levels. [...]". 

Source: Wiley Online Library
Authors: Jane C. Y. Wong et al.
DOI: https://doi.org/10.1002/lno.12367

Read the full article here.

Abstract. 

"Climate change is leading to the loss of oxygen content in the oceans and endangering the survival of many marine species. Due to sea surface temperature warming and changing circulation, the ocean has become more stratified and is consequently losing its oxygen content. Oviparous elasmobranchs are particularly vulnerable as they lay their eggs in coastal and shallow areas, where they experience significant oscillations in oxygen levels. Here, we investigated the effects of deoxygenation (93% air saturation) and hypoxia (26% air saturation) during a short-term period (six days) on the anti-predator avoidance behavior and physiology [...]".

Source: MDPI
Authors: Jaquelino Varela et al.
DOI: https://doi.org/10.3390/biology12040577

Read the full article here.

Abstract. 

"Ocean anoxia was one of the key killing mechanisms responsible for the end-Permian mass extinction (∼252 Ma). However, the temporal evolution and the triggering mechanisms of the end-Permian anoxia are controversial, with the current view being that the water column deoxygenation was a spatially and temporally heterogeneous event. Here, we use cerium-anomalies, uranium contents and rare earth element and yttrium (REY) compositions measured on the carbonate fraction of samples from two marine sections in Armenia and South China to constrain the evolution of end-Permian marine anoxia. [...]". 

Source: Science Direct
Authors: Johann Müller et al.
DOI: https://doi.org/10.1016/j.gloplacha.2023.104067 

Read the full article here.

Call for paper manuscripts closing tomorrow

This is a quick reminder that the call for paper manuscripts for a special issue on "Constraining Uncertainties in Hindcasts and Future Projections of Marine Deoxygenation" in Frontiers in Marine Science ends tomorrow, 7 April 2023. 

Further information: https://www.frontiersin.org/research-topics/24190/constraining-uncertainties-in-hindcasts-and-future-projections-of-marine-deoxygenation. 

Abstract. 

"Aquatic ecosystems are responsible for about 50% of global productivity. They mitigate climate change by taking up a substantial fraction of anthropogenically emitted CO2 and sink part of it into the deep ocean. Productivity is controlled by a number of environmental factors, such as water temperature, ocean acidification, nutrient availability, deoxygenation and exposure to solar UV radiation. Recent studies have revealed that these factors may interact to yield additive, synergistic or antagonistic effects. While ocean warming and deoxygenation are supposed to affect mitochondrial respiration oppositely [...]".

Source: MDPI
Authors: Donat-P. Häder & Kunshan Gao
DOI: https://doi.org/10.3390/w15040817

Read the full article here.

Abstract. 

"Coastal ecosystems play tremendous roles in socio-economic development, but their functions are degrading due to human activities. One of the most alarming degradations is coastal deoxygenation, driven primarily by the over-enrichment of anthropogenic nutrients and organic matter (eutrophication) in the coastal waters. The coastal deoxygenation has led to the worldwide spread of hypoxic zones (where dissolved oxygen concentration is less than 2 mg/L), with the number of reported hypoxic sites increasing from 45 in the 1960s to around 700 nowadays. Besides being perturbed by human activities locally, coastal waters respond more rapidly than [...]".

Source: Frontiers 
Authors: Wenxia Zhang et al.
DOI: https://doi.org/10.3389/fmars.2023.1146877

Read the full article here.

Abstract. 

"The ocean plays an essential role in regulating Earth’s climate. The ocean provides many services, but two crucial ones are its ability to take up heat and carbon dioxide (CO₂) from the atmosphere and cycle both around the world in its vast currents, as well as store them away long term. The ocean is changing rapidly and often unnoticed by the general public. However, as the effects of climate change become more prevalent on the ocean, we will start to see a direct impact on human society. This chapter discusses three main climate change effects on the ocean: ocean warming, acidification, and loss of oxygen. [...]".

Source: Springer Nature
Authors: Helen S. Findlay
DOI: https://doi.org/10.1007/978-3-031-10812-9_2

Read the full article here.

Call for paper manuscripts

We would like to draw your attention to a call for paper manuscripts for a special issue on "Constraining Uncertainties in Hindcasts and Future Projections of Marine Deoxygenation" in Frontiers in Marine Science.

The paper manuscript submission deadline is 7 April 2023.

Further information: https://www.frontiersin.org/research-topics/24190/constraining-uncertainties-in-hindcasts-and-future-projections-of-marine-deoxygenation. 

Abstract. 

"Climate change is undermining the health and integrity of seafloor ecosystems, with declines in bioturbation expected to impact future ecosystem functioning. We explored changes in the nature and degree of bioturbation during Early Jurassic global warming and ocean deoxygenation. Understanding how these communities responded can help anticipate how bioturbation and ecosystem functioning might change over large spatial and temporal scales. Trace and body fossils from outcrop and core in the Cleveland Basin, UK show how healthy seafloor communities deteriorated through the Pliensbachian spinatum Zone, and macroinfaunal behaviour [...]".

Source: Geological Society of London
Authors: Bryony A. Caswell & Liam Herringshaw
DOI: https://doi.org/10.1144/SP529-2022-226

Read the full article here.

Abstract. 

"Sedimentary molybdenum (Mo) and uranium (U) enrichments are widely used to reconstruct changes in bottom water oxygen conditions in aquatic environments. Until now, most studies using Mo and U have focused on restricted suboxic-euxinic basins and continental margin oxygen minimum zones (OMZs), leaving mildly reducing and oxic (but eutrophic) coastal depositional environments vastly understudied. Currently, it is unknown: (1) to what extent Mo and U enrichment factors (Mo- and U-EFs) can accurately reconstruct oxygen conditions in coastal sites experiencing mild deoxygenation, and (2) to what degree secondary [...]". 

Source: Science Direct 
Authors: K. Mareike Paul et al.
DOI: https://doi.org/10.1016/j.chemgeo.2022.121203

Read the full article here.