Linking the progressive expansion of reducing conditions to a stepwise mass extinction event in the late Silurian oceans
"The late Ludlow Lau Event was a severe biotic crisis in the Silurian, characterized by resurgent microbial facies and faunal turnover rates otherwise only documented during the "big five" mass extinctions. This asynchronous late Silurian marine extinction event preceded an associated positive carbon isotope excursion (CIE), the Lau CIE, although a mechanism for this temporal offset remains poorly constrained. [...]"
Authors: Chelsie N. Bowman et al.
Oxygen depletion in ancient oceans caused major mass extinction
"For years, scientists struggled to connect a mechanism to this mass extinction, one of the 10 most dramatic ever recorded in Earth's history. Now, researchers have confirmed that this event, referred to by scientists as the Lau/Kozlowskii extinction, was triggered by an all-too-familiar culprit: rapid and widespread depletion of oxygen in the global oceans. [...]"
Identifying areas prone to coastal hypoxia – the role of topography
"Hypoxia is an increasing problem in marine ecosystems around the world. While major advances have been made in our understanding of the drivers of hypoxia, challenges remain in describing oxygen dynamics in coastal regions. The complexity of many coastal areas and lack of detailed in situ data have hindered the development of models describing oxygen dynamics at a sufficient spatial resolution for efficient management actions to take place. [...]"
Authors: Elina A. Virtanen et al.
Interactions of anaerobic ammonium oxidizers and sulfide-oxidizing bacteria in a substrate-limited model system mimicking the marine environment
"In nature anaerobic ammonium oxidation (anammox) and denitrification processes convert fixed nitrogen to gaseous nitrogen compounds, which are then released to the atmosphere. While anammox bacteria produce N2 from ammonium and nitrite, in the denitrification process nitrate and nitrite are converted to N2 and the greenhouse gas nitrous oxide (N2O). [...]"
Source: FEMS Microbiology Ecology
Authors: Lina Russ et al.
Ferry in Alaska monitors ocean acidification
"The last two years MV Columbia records the ocean’s vitals every three minutes, along a 1,600-kilometer route through the Inside Passage. This includes the coastal region from Puget Sound to the Alaska Panhandle. The ship measures the sea's temperature, salinity, dissolved oxygen content, and carbon dioxide concentration, aiming to monitor ocean acidification. [...]"
Ventilation of the Upper Oxygen Minimum Zone in the Coastal Region Off Mexico: Implications of El Niño 2015–2016
"As a result of anthropogenic activities, it has been predicted that the ocean will be challenged with rising temperature, increased stratification, ocean acidification, stronger more frequent tropical storms, and oxygen depletion. In the tropical Pacific off central Mexico all these phenomena are already occurring naturally, providing a laboratory from which to explore ocean biogeochemical dynamics that are predicted under future anthropogenic forcing conditions. "
Source: Frontiers in Marine Science
Authors: Pablo N. Trucco-Pignata et al.
Quantifying the Relative Importance of Riverine and Open‐Ocean Nitrogen Sources for Hypoxia Formation in the Northern Gulf of Mexico
"The Mississippi and Atchafalaya River System discharges large amounts of freshwater and nutrients into the northern Gulf of Mexico (NGoM). These lead to increased stratification and elevate primary production in the outflow region. Consequently, hypoxia (oxygen <62.5 mmol/m3), extending over an area of roughly 15,000 km2, forms every summer in bottom waters. [...]"
Source: JGR Oceans
Authors: Fabian Große et al.
A Synthesis of Opportunities for Applying the Telecoupling Framework to Marine Protected Areas
"The world’s oceans face unprecedented anthropogenic threats in the globalized era that originate from all over the world, including climate change, global trade and transportation, and pollution. Marine protected areas (MPAs) serve important roles in conservation of marine biodiversity and ecosystem resilience, but their success is increasingly challenged in the face of such large-scale threats. [...]"
Authors: Vanessa Hull et al.
The effect of marine aggregate parameterisations on nutrients and oxygen minimum zones in a global biogeochemical model
"Particle aggregation determines the particle flux length scale and affects the marine oxygen concentration and thus the volume of oxygen minimum zones (OMZs) that are of special relevance for ocean nutrient cycles and marine ecosystems and that have been found to expand faster than can be explained by current state-of-the-art models. [...]"
Author: Daniela Niemeyer et al.
The influence of dissolved organic matter on the marine production of carbonyl sulfide (OCS) and carbon disulfide (CS2) in the Peruvian upwelling
"Oceanic emissions of the climate-relevant trace gases carbonyl sulfide (OCS) and carbon disulfide (CS2) are a major source to their atmospheric budget. Their current and future emission estimates are still uncertain due to incomplete process understanding and therefore inexact quantification across different biogeochemical regimes. [...]"
Source: Ocean Science
Authors: Sinikka T. Lennartz et al.