News

Controls on redox-sensitive trace metals in the Mauritanian oxygen minimum zone

Abstract.

"The availability of the micronutrient iron (Fe) in surface waters determines primary production, N2 fixation, and microbial community structure in large parts of the world's ocean, and thus it plays an important role in ocean carbon and nitrogen cycles. Eastern boundary upwelling systems and the connected oxygen minimum zones (OMZs) are typically associated with elevated concentrations of redox-sensitive trace metals (e.g., Fe, manganese (Mn), and cobalt (Co)), with shelf sediments typically forming a key source. [...]"

Source: Biogeosciences
Authors: Insa Rapp et al.
DOI: 10.5194/bg-16-4157-2019

Read the full article here.


Extinction of cold-water corals on the Namibian shelf due to low oxygen contents

"They were also able to link this event with a shift in the Benguela upwelling system, and an associated intensification of the oxygen minimum zone in this region. The team has now published their findings in the journal Geology.

Known as 'ecosystem engineers', cold-water corals play an important role in the species diversity of the deep sea. The coral species Lophelia pertusa is significantly involved in reef formation. [...]"

Source: EurekAlert!

Read the full article here.


Ocean Deoxygenation and Copepods: Coping with Oxygen Minimum Zone Variability

Abstract.

"Increasing deoxygenation (loss of oxygen) of the ocean, including expansion of oxygen minimum zones (OMZs), is a potentially important consequence of global warming. We examined present day variability of vertical distributions of copepod species in the Eastern Tropical North Pacific (ETNP) living in locations with different water column oxygen profiles and OMZ intensity (lowest oxygen concentration and its vertical extent in a profile). [...]"

Source: Biogeosciences
Authors: Karen F. Wishner, Brad Seibel, and Dawn Outram
DOI: 10.5194/bg-2019-394

Read the full article here.


Seasonal variability of the southern tip of the Oxygen Minimum Zone in the eastern South Pacific (30°‐38°S): A modeling study

Abstract.

"We investigate the seasonal variability of the southern tip (30°–38°S) of the eastern South Pacific oxygen minimum zone (OMZ) based on a high horizontal resolution (1/12°) regional coupled physical‐biogeochemical model simulation. The simulation is validated by available in situ observations and the OMZ seasonal variability is documented. The model OMZ, bounded by the contour of 45 μM, occupies a large volume (4.5x104 km3) during the beginning of austral winter and a minimum (3.5x104 km3) at the end of spring, just 1 and 2 months after the southward transport of the Peru‐Chile Undercurrent (PCUC) is maximum and minimum, respectively.  [...]"

Source: JGR Oceans
Authors: Matias Pizarro‐Koch et al.
DOI: 10.1029/2019JC015201

Read the full article here.


The control of hydrogen sulfide on benthic iron and cadmium fluxes in the oxygen minimum zone off Peru

Abstract.

"Sediments in oxygen-depleted marine environments can be an important sink or source of bio-essential trace metals in the ocean. However, the key mechanisms controlling the release from or burial of trace metals in sediments are not exactly understood. Here, we investigate the benthic biogeochemical cycling of Fe and Cd in the oxygen minimum zone off Peru. We combine bottom water profiles, pore water profiles, as well as benthic fluxes determined from pore water profiles and in-situ from benthic chamber incubations along a depth transect at 12° S. In agreement with previous studies, both concentration-depth profiles and in-situ benthic fluxes indicate a Fe release from sediments into bottom waters. [...]"

Source: Biogeosciences  (Preprint)
Authors: Anna Plass et al.
DOI: 10.5194/bg-2019-390

Read the full article here.


Scenarios of Deoxygenation of the Eastern Tropical North Pacific During the Past Millennium as a Window Into the Future of Oxygen Minimum Zones

Abstract.

"Diverse studies predict global expansion of Oxygen Minimum Zones (OMZs) as a consequence of anthropogenic global warming. While the observed dissolved oxygen concentrations in many coastal regions are slowly decreasing, sediment core paleorecords often show contradictory trends. This is the case for numerous high-resolution reconstructions of oxygenation in the Eastern Tropical North Pacific (ETNP). [...]"

Source: Frontiers in Marine Science
Authors: Konstantin Choumiline et al.
DOI: 10.3389/feart.2019.00237

Read the full article here.


High-throughput screening of sediment bacterial communities from Oxygen Minimum Zones of the northern Indian Ocean

Abstract.

"The Northern Indian Ocean host two recognized Oxygen Minimum Zones (OMZ): one in the Arabian Sea and the other in the Bay of Bengal region. The next-generation sequencing technique was used to understand the total bacterial diversity from the surface sediment of off Goa within the OMZ of Arabian Sea, and from off Paradip within the OMZ of Bay of Bengal. [...]"

Source: Biogeosciences (preprint)
Authors: Jovitha Lincy and Cathrine Manohar
DOI: 10.5194/bg-2019-330

Read the full article here.


Ventilation of the Upper Oxygen Minimum Zone in the Coastal Region Off Mexico: Implications of El Niño 2015–2016

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

Read the full article here.


The effect of marine aggregate parameterisations on nutrients and oxygen minimum zones in a global biogeochemical model

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

Read the full article here.


Microbial diversity of the Arabian Sea in the Oxygen minimum zones by metagenomics approach

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

Read the full article here.


Showing 1 - 10 of 126 results.
Items per Page 10
of 13