Abstract.

"The Atlantic meridional overturning circulation (AMOC) exerts a major control on the global distribution of heat, dissolved oxygen and carbon in the ocean. Yet the timing and cause of the inception of this system and its evolution since the start of the Cenozoic Era 65 million years ago (Ma) remain highly uncertain. Here we present records of microbial source indicators based on glycerol dialkyl glycerol tetraether distributions from the Cenozoic Northwest Atlantic Ocean (~43‒18 Ma) and use them to infer changes in AMOC-driven deep-ocean oxygenation. [...]".

Source: Nature
Authors: Huanye Wang et al.
DOI: https://doi.org/10.1038/s41561-023-01292-2

Read the full article here.

Abstract.

"Ocean deoxygenation, acidification, and decreased phosphorus availability are predicted to increase in coastal ecosystems under future climate change. However, little is known regarding the combined effects of such environmental variables on the green tide macroalga Ulva prolifera. Here, we provide quantitative and mechanistic understanding of the acclimation mechanisms of U. prolifera to ocean deoxygenation, acidification, and phosphorus limitation under both laboratory and semi-natural (mesocosms) conditions. [...]".

Source: Science Direct
Authors: Xintong Huang et al.
DOI: https://doi.org/10.1016/j.scitotenv.2023.164982

Read the full article here.

Abstract.

"Coastal and estuarine ecosystems fringing the North Pacific Ocean are particularly vulnerable to ocean acidification, hypoxia, and intense marine heatwaves as a result of interactions among natural and anthropogenic processes. Here, we characterize variability during a seasonally resolved cruise time series (2014–2018) in the southern Salish Sea (Puget Sound, Strait of Juan de Fuca) and nearby coastal waters for select physical (temperature, T; salinity, S) and biogeochemical (oxygen, O₂; carbon dioxide fugacity, fCO₂; aragonite saturation state, Ω_arag) parameters. [...]".

Source: Biogeosciences
Authors: Simone R. Alin et al.
DOI: https://doi.org/10.5194/bg-21-1639-2024

Read the full article here.

Full title: "Hands-on Hypoxia: Engaging High School Educators in the science behind Marine Microbial Dynamics in Hypoxic Coastal Areas Through Field and Classroom Experiences"

Abstract.

"The University of Southern California’s (USC) Joint Educational Project’s STEM Education Programs hosted a three-day summer workshop focused on marine microbiology and coastal deoxygenation for high school educators. To increase ocean literacy in high school students from Title I schools, topical marine science research was translated into four lesson plans appropriate for classrooms that teach biology and environmental science. [...]".

Source: Current Journal
Authors: Kyla J. Kelly et al.
DOI: https://doi.org/10.5334/cjme.86

Read the full article here.

Abstract.

"The expansion of oxygen deficient zones (ODZs) within the ocean's interior is anticipated to be a major consequence of anthropogenic climate change, but past changes in ODZs are poorly defined. Recent mapping efforts have revealed plumes of the redox-active metal cobalt within ODZs, driving a basin-scale correlation between high cobalt and low O₂. Here, we investigate the cobalt flux to Equatorial Pacific sediments along the Line Islands Ridge as a novel record of basin-scale fluctuations in ODZ extent. [...]".

Source: Wiley Online Library
Authors: Nicholas J. Hawco & Rhea K. Foreman
DOI: https://doi.org/10.1029/2023GL105135

Read the full article here.

Abstract.

"The global ocean is losing oxygen with warming. Observations and Earth system model projections suggest, however, that this global ocean deoxygenation does not equate to a simple and systematic expansion of tropical oxygen minimum zones (OMZs). Previous studies have focused on the Pacific Ocean; they showed that the outer OMZ deoxygenates and expands as oxygen supply by advective transport weakens, the OMZ core oxygenates and contracts due to a shift in the composition of the source waters supplied by slow mixing, and in between these two regimes, oxygen is redistributed with little effect on OMZ volume. [...]".

Source: EGUsphere 
Authors: Sam Ditkovsky et al.
DOI: https://doi.org/10.5194/egusphere-2023-1082

Read the full article here.

Abstract.

"For about 2 decades, oceanographers have been installing oxygen sensors on Argo profiling floats to be deployed throughout the world ocean, with the stated objective of better constraining trends and variability in the ocean's inventory of oxygen. Until now, measurements from these Argo-float-mounted oxygen sensors have been mainly used for localized process studies on air–sea oxygen exchange, upper-ocean primary production, biological pump efficiency, and oxygen minimum zone dynamics. Here, we present a new four-dimensional gridded product of ocean interior oxygen, derived via machine learning algorithms trained on dissolved oxygen [...]".

Source: Earth System Science Data
Authors: Jonathan D. Sharp et al.
DOI: https://doi.org/10.5194/essd-15-4481-2023

Read the full article here.

Full title: "Paleoenvironmental significance of the carbon isotope record across the Cenomanian–Turonian transition and the Oceanic Anoxic Event 2 (OAE2) in the southeastern Neotethys, Zagros, Iran"

Abstract.

"A high–resolution carbon isotope record of pelagic carbonates (δ13Ccarb) from the Zagros Mountains, Iran, documents a 1.8‰ positive carbon isotope excursion (CIE) in the southeastern Neotethys during the Cenomanian–Turonian transition, corresponding to Ocean Anoxic Event (OAE2). The succession is controlled by biostratigraphy that includes the Rotalipora cushmani [...]".

Source: Science Direct
Authors: Borhan Bagherpour et al.
DOI: https://doi.org/10.1016/j.cretres.2023.105574

Read the full article here.

Abstract.

"Sea-level changes exert an important control on oceanic circulation and climate evolution. Researchers have proposed that sea-level rise favored accumulation of sediments enriched in organic carbon during oceanic anoxic events (OAEs), although high-frequency sea-level changes and their controlling mechanism have remained poorly constrained. Here we present a detailed sedimentological and geochemical study on Aptian (Lower Cretaceous) shallow-water carbonates of the Dariyan Formation exposed in the Zagros fold belt of southern Iran. [...]".

Source: Science Direct
Authors: Yiwei Xu et al.
DOI: https://doi.org/10.1016/j.gloplacha.2023.104236

Read the full article here.

GO₂NE Webinar on Ocean Deoxygenation. 

"Do you want to know more about deoxygenation in the ocean?
Join us for the upcoming webinar!

Wednesday, 11th October 2023, 16:00 h – 17:00 CEST

Registration link

Please join the Global Ocean Oxygen Network (IOC Expert Working Group GO2NE) for a new session of its webinar series on ocean deoxygenation. The 23rd webinar will take place 11 October 2023, 16:00 h CEST. The webinar will feature presentations by a more senior and an early-career scientist, 20 minutes each followed by 10 minutes moderated discussion sessions. 

If you are interested to present at one of the upcoming webinars please submit a short abstract here.

Moderation: 
Dimitri Gutierrez 
Instituto del Mar del Perú (IMARPE)

Speakers:
Montserrat Aldunate 
Universidad de Concepción, Chile
"Effect of the oxygen minimum zone on eukaryotic and prokaryotic phytoplankton of the Eastern Tropical North and South Pacific Ocean"

Michelle Graco 
Instituto del Mar del Perú (IMARPE)
"A Long-term Marine-coastal Observatory of low oxygen and acidification in the upwelling system off Peru"

If you want to receive further information about upcoming webinars please register here."