Abstract. 

"Mesozoic oceanic anoxic events are recognized as widespread deposits of marine organic-rich mudrocks temporally associated with mass extinctions and large igneous province emplacement. The Toarcian Oceanic Anoxic Event is one example during which expanded ocean anoxia is hypothesized in response to environmental perturbations associated with emplacement of the Karoo–Ferrar igneous province. However, the global extent of total seafloor anoxia and the relative extent of euxinic (anoxic and sulfide-rich) and non-euxinic anoxic conditions during the Toarcian Oceanic Anoxic Event are poorly constrained. [...]".

Source: Nature
Authors: Alexandra Kunert & Brian Kendall
DOI: https://doi.org/10.1038/s41467-023-36516-x

Read the full article here.

Abstract. 

"The prevalence and frequency of hypoxia events have increased worldwide over the past decade as a consequence of global climate change and coastal biological oxygen depletions. On the other hand, anthropogenic emissions of CO2 and consequent accumulation in the sea surface result in a perturbation of the seawater carbonate system, including a decrease in pH, known as ocean acidification. While the effect of decreases in pH and dissolved oxygen (DO) concentration is better understood, their combined effects are still poorly resolved. [...]". 

Source: Science Direct 
Authors: Murat Belivermiş et al.
DOI: https://doi.org/10.1016/j.marpolbul.2023.114602

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.

Abstract. 

"Benthic species are exposed to oxygen fluctuations that can affect their performance and survival. Physiological effects and ecological consequences of fluctuating oxygen are not well understood in marine bioturbators such as the soft-shell clam Mya arenaria. We explored the effects of different oxygen regimes (21 days of exposure to constant hypoxia (~4.1 kPa PO2), cyclic hypoxia (~2.1–~10.4 kPa PO2) or normoxia (~21 kPa PO2)) on energy metabolism, oxidative stress and ecological behaviors (bioirrigation and bioturbation) of M. arenaria. Constant hypoxia and post-hypoxic recovery in cyclic hypoxia led to oxidative injury of proteins and [...]".

Source: Science Direct 
Authors: Natascha Ouillon et al.
DOI: https://doi.org/10.1016/j.scitotenv.2022.160459

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. 

Call for Abstract and Early Registration closing on 23 February 2023

ASLO Aquatic Sciences Meeting 2023: 4–9 June 2023 in Palma de Mallorca, Spain

Resilience and Recovery in Aquatic Systems

Sessions on ocean oxygen, deoxygenation, anoxia, and hypoxia:

• SS015 Deoxygenation in the Past, Present and Future Ocean
• SS050 Disentangling Complex Long-Term pH and O2 Trends in Coastal and Estuarine Systems From Global and Regional Drivers
• SS107 Oxic-Anoxic Interfaces: Pathways, Dynamics and Exchanges

For further information, please visit the event's homepage, sessions list, registration information, and abstract preparation guide. 

ASLO Aquatic Sciences Meeting 2023: 4–9 June 2023 in Palma de Mallorca, Spain

Resilience and Recovery in Aquatic Systems

"Concepts of resilience and recovery do not only apply to aquatic ecosystems but also to societies when faced with disruptions and crises. Past events have shown that adaptability and decisiveness are important keys to resilience and recovery. Disruptions are opportune moments for setting up strategies for management and recovery. Faced with the COVID-19 pandemic, ASLO meetings have adapted by transforming the ASM 2021 Palma meeting to virtual with a positive attitude that in 2023 we will recover and meet in-person. Positivity is also an important factor.  We do not dwell on problems, but we try to look for solutions and get united for whatever crisis we face.  
We will incorporate the theme of resilience and recovery in aquatic systems into the plenary sessions and encourage submissions that examine these topics and invite you to contribute special sessions on topics relevant to freshwater and marine ecosystems."

Sessions on ocean oxygen, deoxygenation, anoxia, and hypoxia:

• SS015 Deoxygenation in the Past, Present and Future Ocean
• SS050 Disentangling Complex Long-Term pH and O2 Trends in Coastal and Estuarine Systems From Global and Regional Drivers
• SS107 Oxic-Anoxic Interfaces: Pathways, Dynamics and Exchanges

For further information, please visit the event's homepage and sessions list. 

Abstract. 

"Despite carbon-cycle perturbations at a global scale during the early Toarcian, the extent of anoxia during the ∼182-Ma Toarcian Oceanic Anoxic Event (T-OAE) remains in debate. A common factor in the development of oceanic anoxia is watermass restriction, which is thought to have been important in the NW European Seaway, but whose influence elsewhere is relatively unstudied. Here, we analyze Mo/TOC (a proxy for watermass restriction) and redox proxies (e.g., Corg/P) in two sections of the Asturian Basin (northern Iberian Paleomargin), and we integrate these results with data from a suite of global Toarcian sections in order to reassess [...]".

Source: Science Direct 
Authors: Javier Fernández-Martínez et al.
DOI: https://doi.org/10.1016/j.gloplacha.2022.104026

Read the full article here.

Abstract. 

"The northern Gulf of Mexico (nGOM) hypoxic zone is a shallow water environment where methane, a potent greenhouse gas, fluxes from sediments to bottom water and remains trapped due to summertime stratification. When the water column is destratified, an active planktonic methanotrophic community could mitigate the efflux of methane, which accumulates to high concentrations, to the atmosphere. To investigate the possibility of such a biofilter in the nGOM hypoxic zone we performed metagenome assembly, and metagenomic and metatranscriptomic read mapping. Methane monooxygenase (pmoA) was an abundant [...]".

Source: Oxford Academic
Authors: Kathryn L. Howe et al.
DOI: https://doi.org/10.1093/femsec/fiac153

Read the full article here.