Abstract.

"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. [...]"

Source: GeoScienceWorld
Authors: Chelsie N. Bowman et al.
DOI: 10.1130/G46571.1

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"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. [...]"

Source: ScienceDaily

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Abstract.

"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. [...]"

Source: Biogeosciences
Authors: Elina A. Virtanen et al.
DOI: 10.5194/bg-16-3183-2019

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Abstract. 

"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. 
DOI: 10.1093/femsec/fiz137

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"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. [...]"

Source: Safety4Sea

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Abstract.

"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.
DOI: 10.3389/fmars.2019.00459

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Abstract.

"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.
DOI: 10.1029/2019JC015230

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Abstract.

"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. [...]"

Source: Sustainability
Authors: Vanessa Hull et al.
DOI: 10.3390/su11164450

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Abstract.

"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. [...]"

Source: Biogeosciences
Author: Daniela Niemeyer et al.
DOI: 10.5194/bg-16-3095-2019

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Abstract.

"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.
DOI: 10.5194/os-15-1071-2019

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"What will the ecology of the Salish Sea look like in the year 2095?

It's an important question for millions of people who live along and near the shores of this intricate, interconnected network of coastal waterways, inlets, bays, and estuaries that encompasses Puget Sound in Washington state and the deep waters of southwest British Columbia. A research team from PNNL found that the inner Salish Sea is resilient, and that future response to climate change—while significant—will be less severe than the open ocean. [...]"

Source: phys.org

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Abstract.

"Methane (CH4) in marine sediments has the potential to contribute to changes in the ocean and climate system. Physical and biochemical processes that are difficult to quantify with current standard methods such as acoustic surveys and discrete sampling govern the distribution of dissolved CH4 in oceans and lakes. [...]"

Source: Ocean Science
Authors: Pär Jansson et al. 
DOI: 10.5194/os-15-1055-2019

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Abstract.

"Oxygen is a prerequisite for all large and motile animals. It is a puzzling paradox that fossils of benthic animals are often found in black shales with geochemical evidence for deposition in marine environments with anoxic and sulfidic bottom waters. It is debated whether the geochemical proxies are unreliable, affected by diagenesis, or whether the fossils are transported from afar or perhaps were not benthic.  [...]"

Source: Scientific Reports
Authors: Tais W. Dahl et al.
DOI: 10.1038/s41598-019-48123-2

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Abstract.

"Ocean boundary current systems are key components of the climate system, are home to highly productive ecosystems, and have numerous societal impacts. Establishment of a global network of boundary current observing systems is a critical part of ongoing development of the Global Ocean Observing System. The characteristics of boundary current systems are reviewed, focusing on scientific and societal motivations for sustained observing. Techniques currently used to observe boundary current systems are reviewed, followed by a census of the current state of boundary current observing systems globally. The next steps in the development of boundary current observing systems are considered, leading to several specific recommendations. [...]"

Source: Frontiers in Marine Science
Authors: Robert E. Todd et al.
DOI: 10.3389/fmars.2019.00423

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Abstract.

"Large oxygen depleted areas known as oxygen minimum zones (OMZ) have been observed in the Arabian Sea and recent reports indicate that these areas are expanding at an alarming rate. In marine waters, oxygen depletion may also be related to global warming and the temperature rise, acidification and deoxygenation can lead to major consequences wherein the plants, fish and other biota will struggle to survive in the ecosystem. [...]"

Source: bioRxiv
Authors: Mandar S Paingankar et al.
DOI: 10.1101/731828

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Abstract.

"Subseafloor microbial activities are central to Earth’s biogeochemical cycles. They control Earth’s surface oxidation and major aspects of ocean chemistry. They affect climate on long timescales and play major roles in forming and destroying economic resources. In this review, we evaluate present understanding of subseafloor microbes and their activities, identify research gaps, and recommend approaches to filling those gaps. [...]"

Source: Nature Communications
Authors: Steven D’Hondt et al.
DOI: 10.1038/s41467-019-11450-z

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"Ocean acidification is bad news for shellfish, as it makes it harder for them to form their calcium-based shells. But climate change could also have multiple other impacts that make California bays less hospitable to shelled organisms like oysters, which are a key part of the food web.

Changes to water temperature and chemistry resulting from human-caused climate change could shrink the prime habitat and farming locations for oysters in California bays, according to a new study from the University of California, Davis. [...]"

Source: Science Daily

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Abstract.

"A decline in global ocean oxygen concentrations has been observed over the twentieth century and is predicted to continue under future climate change. We use a unique modeling framework to understand how the perturbed ocean circulation may influence the rate of ocean deoxygenation in response to a doubling of atmospheric CO₂ and associated global warming. [...]"

Source: Global Biogeochemical Cycles
Authors: Jaime B. Palter and David S. Trossman
DOI: 10.1002/2017GB005777

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"NASA has selected a space-based instrument under its Earth Venture Instrument (EVI) portfolio that will make observations of coastal waters to help protect ecosystem sustainability, improve resource management, and enhance economic activity. The selected Geosynchronous Littoral Imaging and Monitoring Radiometer (GLIMR) instrument, led by principal investigator Joseph Salisbury at the University of New Hampshire, Durham, will provide unique observations of ocean biology, chemistry, and ecology in the Gulf of Mexico, portions of the southeastern United States coastline, and the Amazon River plume—where the waters of the Amazon River enter the Atlantic Ocean.[...]"

Source: phys.org

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Abstract.

"The Argo Program has been implemented and sustained for almost two decades, as a global array of about 4000 profiling floats. Argo provides continuous observations of ocean temperature and salinity versus pressure, from the sea surface to 2000 dbar. The successful installation of the Argo array and its innovative data management system arose opportunistically from the combination of great scientific need and technological innovation. Through the data system, Argo provides fundamental physical observations with broad societally-valuable applications, built on the cost-efficient and robust technologies of autonomous profiling floats. [...]"

Source: Frontiers in Marine Science
Authors: Dean Roemmich et al.
DOI: 10.3389/fmars.2019.00439

Read the full article here. 

Hurricane Barry dampens initial size predictions

"This year’s Gulf of Mexico “dead zone”— an area of low oxygen that can kill fish and marine life — is approximately 6,952 square miles, according to NOAA-supported scientists. The measured size of the dead zone, also called the hypoxic zone, is the 8th largest in the 33-year record and exceeds the 5,770-square-mile average from the past five years. [...]"

Source: NOAA

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