News

A benthic oxygen oasis in the early Neoproterozoic ocean

Abstract.

"Benthic oxygen oases linked to photosynthetic mats have been reported in modern anoxic aquatic systems. Benthic macroalgal blooms were common in stratified, anoxic Neoproterozoic oceans, leading us to hypothesize the existence of benthic oxygen oases at that time. This hypothesis has significant implications regarding the bioavailability of transition metals (e.g., Cu, Zn, Ni, Mo, V) and the distribution of aerobic eukaryotes in these oceans[...]"

 

Source: Science Direct
Authors: Haiyang Wang et al.
DOI: https://doi.org/10.1016/j.precamres.2020.106085

Read the full article here.


Protecting the global ocean for biodiversity, food and climate

Abstract.

"The ocean contains unique biodiversity, provides valuable food resources and is a major sink for anthropogenic carbon. Marine protected areas (MPAs) are an effective tool for restoring ocean biodiversity and ecosystem services1,2, but at present only 2.7% of the ocean is highly protected3. This low level of ocean protection is due largely to conflicts with fisheries and other extractive uses. To address this issue[...]"

 

Source: Nature
Authors: Enric Sala et al.
DOI: https://doi.org/10.1038/s41586-021-03371-z

Read the full article here.


Observed Seasonal and Interannual Controls on Coastal Oxygen and Dead Zones in the Indian Ocean

Abstract.

"A major concern is that global de-oxygenation will expand Oxygen minimum zones (OMZs) and favor coastal dead zones (DZs) where already low oxygen levels threaten ecosystems and adjacent coastal economies. The northern Indian ocean is home to both intense OMZs and DZs, and is surrounded by many kilometers of biodiverse and commercially valuable coastline. Exchanges between OMZs and shelf waters that contribute to coastal DZs are subject to the strong monsoonal seasonal cycle[...]"

 

Source: EGU General Assambly
Authors: Jenna Pearson et al.
DOI: https://doi.org/10.5194/egusphere-egu21-1421

Read the full article here.


Intrinsic oceanic decadal variability of upper-ocean heat content

Abstract.

"Atmosphere and ocean are coupled via air–sea interactions. The atmospheric conditions fuel the ocean circulation and its variability, but the extent to which ocean processes can affect the atmosphere at decadal time scales remains unclear. In particular, such low-frequency variability is difficult to extract from the short observational record, meaning that climate models are the primary tools deployed to resolve this question. Here, we assess how the ocean’s intrinsic variability leads to patterns of upper-ocean heat content [...]"

 

Source: AMS- American Meteorological Society
Authors: Navid C. Constantinou et al.
DOI: https://doi.org/10.1175/JCLI-D-20-0962.1

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.


How deep ocean-land coupling controls the generation of secondary microseism Love waves

Abstract.

"Wind driven ocean wave-wave interactions produce continuous Earth vibrations at the seafloor called secondary microseisms. While the origin of associated Rayleigh waves is well understood, there is currently no quantified explanation for the existence of Love waves in the most energetic region of the microseism spectrum (3–10 s). Here, using terrestrial seismic arrays and 3D synthetic acoustic-elastic simulations combined with ocean wave hindcast data, we demonstrate that, observed from land[...]"

 

Source: Nature Communications
Authors: Florian Le Pape et al.
DOI: https://doi.org/10.1038/s41467-021-22591-5

Read the full article here.


Warum Sauerstoff im Meer fehlt

Video recommendation.

"Im Meer gibt es immer mehr Stellen, in denen es kaum noch Sauerstoff gibt: sogenannte "Todeszonen". Wir erklären euch, warum das ein Problem ist."

Source: ZDF
 

watch the video 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.


A committed fourfold increase in ocean oxygen loss

Abstract.

"Less than a quarter of ocean deoxygenation that will ultimately be caused by historical CO2 emissions is already realized, according to millennial-scale model simulations that assume zero CO2 emissions from year 2021 onwards. About 80% of the committed oxygen loss occurs below 2000 m depth, where a more sluggish overturning circulation will increase water residence times and accumulation of respiratory oxygen demand. According to the model results, the deep ocean will thereby lose more than 10% of its pre-industrial oxygen content even if CO2 emissions and thus global warming[...]"

 

Source: Nature Communications
Authors: Andreas Oschlies 
DOI: https://doi.org/10.1038/s41467-021-22584-4

Read the full article here.