News

Spatially heterogenous seawater δ34S and global cessation of Ca-sulfate burial during the Toarcian oceanic anoxic event

Abstract.

"The early Toarcian of the Early Jurassic saw a long-term positive carbon-isotope excursion (CIE) abruptly interrupted by a significant negative excursion (nCIE), associated with rapid global warming and an oceanic anoxic event (T-OAE, ∼183 Ma). However, the detailed processes and mechanisms behind widespread ocean deoxygenation are unclear. Here, we present high-resolution carbonate-associated sulfate sulfur-isotope [...]".

 

Source: Science Direct
Authors: Zhong Han et al.
DOI: https://doi.org/10.1016/j.epsl.2023.118404

Read the full article here.


Woods Hole Oceanographic Institute Bioseminar

Title: "Microbially-Driven Shifts in Marine Nutrient Cycling in Response to Ocean Deoxygenation and Climate Change"

Speaker: Julia Huggins

Event Date:  -

"The oceans are currently losing dissolved oxygen (O2) as a result of climate change and human activity, which may have dramatic effects on biodiversity and global climate feedbacks. As O2 is depleted to near-anoxia in pelagic marine environments, microorganisms shift from aerobic respiration to anaerobic nitrogen-based metabolisms. Most conceptual and numerical models assume this shift will lead to nitrogen loss, but it can also lead to nitrogen retention depending on which microbial metabolism(s) engage. The controls regulating the relative activity and variability of these metabolisms remain uncertain, however, and this confounds our efforts to predict how the marine nitrogen cycle responds to deoxygenation and impacts other marine biogeochemical cycles. I conduct experiments with live marine microbial communities to measure how different nitrogen-based microbial metabolisms are regulated in the transition from oxic to anoxic conditions. I use a combination of stable nitrogen isotopes (15N) and bioinformatics technologies to increase our knowledge of how competing microbial metabolisms are regulated under variable environmental conditions and unstable resource availability. My work has implications for our biogeochemical models that predict ocean deoxygenation and related climate feedbacks."

You can find more information here and you can join the webinar here.


../common/calendar Start Date: 12/5/23

European Marine Board Webinar on Ocean Deoxygenation

Title: "Sailing for oxygen - how citizen science can help understand ocean deoxygenation"

Event Date:  -

"On Thursday 7 December 2023, EMB will host its 35th Third Thursday Science Webinar featuring Toste Tanhua who will speak about "Sailing for oxygen - how citizen science can help understand ocean deoxygenation".

This topic is linked to the science within the EMB Future Science Brief No. 10 'Ocean oxygen: the role of the Ocean in the oxygen we breathe and the threat of deoxygenation'.

Toste Tanhua is a Senior Scientist at GEOMAR (Germany) and chemical oceanographer. His work focuses on Ocean ventilation by observing transient tracers and conducting deliberate tracer release experiments to understand ventilation and mixing in the Ocean. He also works on understanding the dynamics of Ocean carbon, nutrients and oxygen. In addition, he is co-chairing the steering committee of the Global Ocean Observing System (GOOS) and coordinating the EU funded project EuroSea, that aims at improving the ocean observing and forecasting system."

You can find more information here and you can register for the webinar here.


../common/calendar Start Date: 12/7/23

“Hypoxic” Silurian oceans suggest early animals thrived in a low-O2 world

Abstract.

"Atmospheric oxygen (O2) concentrations likely remained below modern levels until the Silurian–Devonian, as indicated by several recent studies. Yet, the background redox state of early Paleozoic oceans remains poorly constrained, hampering our understanding of the relationship between early animal evolution and O2. Here, we present a multi-proxy analysis of redox conditions in the Caledonian foreland basin to Baltica from the early to the mid-Silurian. [...]".

 

Source: Science Direct 
Authors: Emma R. Haxen et al.
DOI: https://doi.org/10.1016/j.epsl.2023.118416

Read the full article here.


Mentoring the next generation of ocean deoxygenation and acidification scientists

Intro.

"UNESCO’s Intergovernmental Oceanographic Commission (IOC/UNESCO), El Centro de Estudios Avanzados en Zonas Áridas (CEAZA) and the Universidad Catolica del Norte, as well as many other partners and sponsors organized the GOOD-OARS-CLAP-COPAS Summer School from 6-12 November 2023 in La Serena, Chile, to teach the latest science of ocean acidification and deoxygenation."

Source: IOC-UNESCO

For further information, please read here


Ocean deoxygenation caused non-linear responses in the structure and functioning of benthic ecosystems

Abstract.

"The O2 content of the global ocean has been declining progressively over the past decades, mainly because of human activities and global warming. Nevertheless, how long-term deoxygenation affects macrobenthic communities, sediment biogeochemistry and their mutual feedback remains poorly understood. Here, we evaluate the response of the benthic assemblages and biogeochemical functioning to decreasing O2 concentrations along the persistent bottom-water dissolved O2 gradient of the Estuary and Gulf of St. Lawrence (QC, Canada). [...]".

 

Source: Wiley Online Library
Authors: Ludovic Pascal et al.
DOI: https://doi.org/10.1111/gcb.16994

Read the full article here.


Future change of summer hypoxia in coastal California Current

Abstract.

"The occurrences of summer hypoxia in coastal California Current can significantly affect the benthic and pelagic habitat and lead to complex ecosystem changes. Model-simulated hypoxia in this region is strongly spatially heterogeneous, and its future changes show uncertainties depending on the model used. Here, we used an ensemble of the new generation Earth system models to examine the present-day and future changes of summer hypoxia in this region. We applied model-specific thresholds combined with empirical bias adjustments of the dissolved oxygen variance to identify hypoxia. [...]".

 

Source: Frontiers in Marine Science 
Authors: Hui Shi et al.
DOI: https://doi.org/10.3389/fmars.2023.1205536

Read the full article here.


Stratigraphic architecture of the Tethyan Cenomanian-Turonian succession and OAE2 in the Dokan Area, Kurdistan Region, northeast Iraq

Abstract.

"This study provides a detailed examination of a condensed Cenomanian-Turonian (C-T) succession of two sections (Dokan Dam and Khalakan) in the Kurdistan Region, Northeastern Iraq, based on biostratigraphy (calcareous nannofossils and planktic foraminifera), carbon and oxygen isotope geochemistry, and facies analysis. The C/T boundary in this region is characterized by a hiatus noticeable due to the absence of the Globigerinelloides benthonensis and Dicarinella hagni subzones and the lack of positive carbon isotope excursion (CIE) peak b during the Oceanic Anoxic Event 2 (OAE2). [...]".

 

Source: Science Direct
Authors: Fadhil A. Lawa et al.
DOI: https://doi.org/10.1016/j.jafrearsci.2023.105064

Read the full article here.


Decadal variability of oxygen uptake, export, and storage in the Labrador Sea from observations and CMIP6 models

Abstract.

"The uptake of dissolved oxygen from the atmosphere via air-sea gas exchange and its physical transport away from the region of uptake are crucial for supplying oxygen to the deep ocean. This process takes place in a few key regions that feature intense oxygen uptake, deep water formation, and physical oxygen export. In this study we analyze one such region, the Labrador Sea, utilizing the World Ocean Database (WOD) to construct a 65–year oxygen content time series in the Labrador Sea Water (LSW) layer (0–2200 m). [...]".

 

Source: Frontiers in Marine Science 
Authors: Jannes Koelling et al.
DOI: https://doi.org/10.3389/fmars.2023.1202299

Read the full article here.


Job Offer in a project on understanding the consequences of marine heatwaves for terrestrial and marine systems in Northwestern Europe

PhD position at the ACCE (Adapting to the Challenges of a Changing Environment) at the University of York 

"Recent high-profile and extraordinary marine heatwaves (e.g. the Pacific “Blob”) have galvanised the scientific community to better understand climate-driven extreme events in the ocean and their potential ecosystem impacts. The North Sea is a global hot spot for marine heatwaves, with many marine species already exceeding their comfortable thermal range. Marine heatwaves can also significantly influence air temperature patterns over land, with warm sea temperatures having been identified as a main driver of the record-breaking UK summer heatwave of 2018."

You can find more details here.


Showing 41 - 50 of 1,187 results.
Items per Page 10
of 119

Newsletter

It is possible to subscribe to our email newsletter list.

Depending on the amount of publications, we will summarize the activities on this blog in a newsletter for everyone not following the blog regularly.

If you want to subscribe to the email list to receive the newsletter, please send an email to sfb754@geomar.de with the header "subscribe".

If you want to unsubscribe from the newsletter, please send an email to sfb754@geomar.de with the header "unsubscribe".

You cannot forward any messages as a regular member to the list. If you want to suggest new articles or would like to contact us because of any other issue, please send an email to sfb754@geomar.de.

GOOD Social Media

To follow GOOD on LinkedIn, please visit here.
 

To follow GOOD on Twitter, please visit here.


To follow GOOD on Blue Sky, please visit here