Mysterious ‘shadow zone’ traps 2000-year-old water
"A MYSTERIOUS abyss in the ocean known as the “shadow zone” traps ancient water dating back to 400AD. We now know why it’s there.
IT’S called the “shadow zone” and it lies around two kilometres below the surface in an ocean abyss where trapped water dates back to the fourth century.
This ancient water, which is between 1000 and 2000 years old, dates back to when the ancient Germanic tribe the Goths instigated the end of the Western Roman Empire and the rise of Medieval Europe. [...]"
M/V Columbia starts its study of ocean acidification
"An Alaska state ferry recently started work doubling as an ocean research platform.
The M/V Columbia, which conducts weekly runs between Bellingham, Washington and Alaska, has been installed with a seawater monitoring system to study ocean acidification, a byproduct of human-caused climate change which could affect sea life in Alaska and around the world. [...]"
Source: Juneau Empire
Climate and anthropogenic controls of coastal deoxygenation on interannual to centennial timescales
"Understanding dissolved oxygen variability in the ocean is limited by the short duration of direct measurements, however sedimentary oxidation-reduction reactions can provide context for modern observations. Here we use bulk sediment redox-sensitive metal enrichment factors (MoEF, ReEF, and UEF) and scanning X-ray fluorescence (XRF) records to examine annual-scale sedimentary oxygen concentrations in the Santa Barbara Basin from the Industrial Revolution (AD ~1850) to present. [...]"
Source: Geophysical Research Letters
Authors: Yi Wang, Ingrid Hendy, Tiffany J. Napier
The Northern Gulf of Mexico During OAE2 and the Relationship Between Water Depth and Black Shale Development
"Despite their name, Oceanic Anoxic Events (OAEs) are not periods of uniform anoxia and black shale deposition in ancient oceans. Shelf environments account for the majority of productivity and organic carbon burial in the modern ocean, and this was likely true in the Cretaceous as well. However, it is unlikely that the mechanisms for such an increase were uniform across all shelf environments. [...]"
Authors: Christopher M. Lowery
Read the full article here.
Hydrography in the Mediterranean Sea during a cruise with RV Tethys 2 in May 2015
"We report on data from an oceanographic cruise, covering western, central and eastern parts of the Mediterranean Sea, on the French research vessel Tethys 2 in May 2015. This cruise was fully dedicated to the maintenance and the metrological verification of a biogeochemical observing system based on a fleet of BGC-Argo floats. During the cruise, a comprehensive dataset of parameters sensed by the autonomous network was collected. [...]"
Source: Earth System Science Data (unter review)
Authors: Vincent Taillandier et al.
A dynamic microbial community with high functional redundancy inhabits the cold, oxic subseafloor aquifer
"The rock-hosted subseafloor crustal aquifer harbors a reservoir of microbial life that may influence global marine biogeochemical cycles. Here we utilized metagenomic libraries of crustal fluid samples from North Pond, located on the flanks of the Mid-Atlantic Ridge, a site with cold, oxic subseafloor fluid circulation within the upper basement to query microbial diversity. [...]"
Source: The ISME Journal
Authors: Benjamin J. Tully et al.
Read the full article here.
50-years of data from a 'living oxygen minimum' lab could help predict the oceans' future
The mass of data, collected in two new Nature family papers, could help scientists better predict the impact of human activities and ocean deoxygenation on marine environments. Currently, oxygen minimum zones (OMZs) constitute up to 7 percent of global ocean volume. Continued expansion of OMZs in the northeastern subarctic Pacific has the potential to transport oxygen-depleted waters into coastal regions, adversely affecting nutrient cycles and fisheries productivity. [...]"
Source: University of British Columbia (media contact: Chris Balma)
The OMZ and nutrient features as a signature of interannual and low-frequency variability in the Peruvian upwelling system
"Over the last decades, the Humboldt Current upwelling ecosystem, particularly the northern component off the coast of Peru, has drawn the interest of the scientific community because of its unique characteristics: it is the upwelling system with the biggest catch productivity despite the fact it is embedded in a shallow and intense oxygen minimum zone (OMZ). [...]"
Authors: Michelle I. Graco et al.
Read the full article here.
Monitoring microbial responses to ocean deoxygenation in a model oxygen minimum zone
"Today in Scientific Data, two compendia of geochemical and multi-omic sequence information (DNA, RNA, protein) generated over almost a decade of time series monitoring in a seasonally anoxic coastal marine setting are presented to the scientific community. These data descriptors introduce a model ecosystem for the study of microbial responses to ocean deoxygenation, a phenotype that is currently expanding due to climate change."
Source: Scientific Data
Authors: Steven J. Hallam, Mónica Torres-Beltrán & Alyse K. Hawley
Ocean acidification could doom key Arctic fish species: study
Ocean acidification combined with warming of the world oceans and loss of oxygen is having a severe impact on key Arctic marine species such as polar cod in the Barents Sea, according to a new study conducted by German scientists.
"The eight-year interdisciplinary study, which began in 2009 and involved more than 250 scientist in the German research network on ocean acidification BIOACID (Biological Impacts of Ocean Acidification), investigated how different marine species respond to ocean acidification – a change in the ocean chemistry that occurs when carbon dioxide (CO2) from the atmosphere dissolves in seawater.
In addition to ocean acidification, the study, Exploring Ocean Change: Biological Impacts of Ocean Acidification, also examined the cascading effect of other stressors such as ocean warming, deoxygenation, overfishing and eutrophication – the increased concentration of nutrients in estuaries and coastal waters that causes harmful algal blooms, ocean dead zones and fish kills. [...]"
Source: The Independent Barents Observer