Stepwise oxygenation of early Cambrian ocean controls early metazoan diversification
"The Ediacaran–Cambrian transition is a critical period in Earth history, during which both marine environment and life experienced drastic changes. It was suggested that pervasive oxygenation and associated chemical changes in the ocean have potentially triggered the rapid diversification of early Cambrian metazoans. The timing and process of ocean oxygenation, however, have not been well constrained. [...]"
Source: Palaeogeography, Palaeoclimatology, Palaeoecology
Authors: Xiangkuan Zhao et al.
Oxygen minimum zone cryptic sulfur cycling sustained by offshore transport of key sulfur oxidizing bacteria
"Members of the gammaproteobacterial clade SUP05 couple water column sulfide oxidation to nitrate reduction in sulfidic oxygen minimum zones (OMZs). Their abundance in offshore OMZ waters devoid of detectable sulfide has led to the suggestion that local sulfate reduction fuels SUP05-mediated sulfide oxidation in a so-called “cryptic sulfur cycle”. [...]"
Source: Nature Communications
Authors: Cameron M. Callbeck et al.
The Baltic Sea as a time machine for the future coastal ocean
"Coastal global oceans are expected to undergo drastic changes driven by climate change and increasing anthropogenic pressures in coming decades. Predicting specific future conditions and assessing the best management strategies to maintain ecosystem integrity and sustainable resource use are difficult, because of multiple interacting pressures, uncertain projections, and a lack of test cases for management. [...]"
Source: Science Advances
Authors: Thorsten B. H. Reusch et al.
A Sixteen-year Decline in Dissolved Oxygen in the Central California Current
"A potential consequence of climate change is global decrease in dissolved oxygen at depth in the oceans due to changes in the balance of ventilation, mixing, respiration, and photosynthesis. We present hydrographic cruise observations of declining dissolved oxygen collected along CalCOFI Line 66.7 (Line 67) off of Monterey Bay, in the Central California Current region, and investigate likely mechanisms. [...]"
Source: Scientific Reports
Authors: Alice S. Ren et al.
The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay
"The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic–biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. [...]"
Authors: Isaac D. Irby et al.
Coupling of oceanic carbon and nitrogen facilitates spatially resolved quantitative reconstruction of nitrate inventories
"Anthropogenic impacts are perturbing the global nitrogen cycle via warming effects and pollutant sources such as chemical fertilizers and burning of fossil fuels. Understanding controls on past nitrogen inventories might improve predictions for future global biogeochemical cycling. Here we show the quantitative reconstruction of deglacial bottom water nitrate concentrations from intermediate depths of the Peruvian upwelling region, using foraminiferal pore density. [...]"
Source: Nature Communications
Authors: Nicolaas Glock et al.
Oxygen Saturation Surrounding Deep Water Formation Events in the Labrador Sea From Argo‐O2 Data
"Deep water formation supplies oxygen‐rich water to the deep sea, spreading throughout the ocean by means of the global thermohaline circulation. Models suggest that dissolved gases in newly formed deep water do not come to equilibrium with the atmosphere. However, direct measurements during wintertime convection are scarce, and the controls over the extent of these disequilibria are poorly quantified [...]"
Source: Global Biogeochemical Cycles
Authors: Mitchell K. Wolf et al.
New insights into Cenomanian paleoceanography and climate evolution from the Tarfaya Basin, southern Morocco
"A 325 m long continuous succession of uppermost Albian to lower Turonian pelagic (outer shelf) deposits was recovered from a new drill site in the central part of the Tarfaya Basin (southern Morocco). Natural gamma ray wireline logging, carbonate and organic carboncontent, bulk carbonate and organic carbon stable isotopes and X-ray fluorescence (XRF)-scanner derived elemental distribution data in combination with planktonic foraminiferal biostratigraphy indicate complete recovery of the Cenomanian Stage. [...]"
Source: Cretaceous Research
Authors: SebastianBeil et al.
Physical controls on oxygen distribution and denitrification potential in the north west Arabian Sea
"At suboxic oxygen concentrations, key biogeochemical cycles change and denitrification becomes the dominant remineralization pathway. Earth system models predict oxygen loss across most ocean basins in the next century; oxygen minimum zones near suboxia may become suboxic and therefore denitrifying. Using an ocean glider survey and historical data, we show oxygen loss in the Gulf of Oman (from 6‐12 to < 2 μmol kg‐1) not represented in climatologies. [...]"
Source: Grophysical Research Letters
Authors: B. Y. Queste et al.
Deglacial upwelling, productivity and CO2 outgassing in the North Pacific Ocean
"The interplay between ocean circulation and biological productivity affects atmospheric CO2 levels and marine oxygen concentrations. During the warming of the last deglaciation, the North Pacific experienced a peak in productivity and widespread hypoxia, with changes in circulation, iron supply and light limitation all proposed as potential drivers. [...]"
Source: Nature Geoscience
Authors: William R. Gray et al.