Evaluating the promise and pitfalls of a potential climate change–tolerant sea urchin fishery in southern California
"Marine fishery stakeholders are beginning to consider and implement adaptation strategies in the face of growing consumer demand and potential deleterious climate change impacts such as ocean warming, ocean acidification, and deoxygenation. This study investigates the potential for development of a novel climate change-tolerant sea urchin fishery in southern California based on Strongylocentrotus fragilis (pink sea urchin), a deep-sea species whose peak density was found to coincide with a current trap-based spot prawn fishery (Pandalus platyceros) in the 200–300-m depth range. [...]"
Source: ICES Journal of Marine Science
Authors: Kirk N Sato et al.
Patterns of deoxygenation: sensitivity to natural and anthropogenic drivers
"Observational estimates and numerical models both indicate a significant overall decline in marine oxygen levels over the past few decades. Spatial patterns of oxygen change, however, differ considerably between observed and modelled estimates. Particularly in the tropical thermocline that hosts open-ocean oxygen minimum zones, observations indicate a general oxygen decline, whereas most of the state-of-the-art models simulate increasing oxygen levels. Possible reasons for the apparent model-data discrepancies are examined. [...]"
Source: Philosophical Transactions of the Royal Socie
Authors: Andreas Oschlies et al.
Bacterial Community Profiling of the Arabian Sea Oxygen Minimum Zone Sediments using Cultivation Independent Approach
"The eastern Arabian Sea has a unique and permanent oxygen minimum zone (OMZ) that extends along the western continental margin of India. In order to understand the bacterial community structure and diversity of OMZ sediment of the Arabian Sea (AS), PCR-DGGE analysis were carried out for samples collected off Ratnagiri, Goa and Karwar at 50m, 200m, 500m and 1000m depths. [...]"
Source: Examines Mar Biol Oceanogr
Authors: Baby Divya, Annie Feby and Shanta Nair
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Biodiversity surprises at bubbly deep-sea cold seeps along Cascadia fault
"A new study led by Oregon State University (OSU) graduate student Sarah Seabrook that uses scientific data and samples from Ocean Networks Canada (ONC) focuses on the extent, variability, and complexity of species—from microbes to tubeworms—found at deep-sea cold seep habitats along the Cascadia fault off the west coast of North America.
The study reports for the first time on the surprisingly rich and diverse microbial and animal communities at eight recently discovered cold seeps, comparing these new sites off the coasts of Washington, Oregon, and northern California with two known seeps off the coast of British Columbia at Barkley Canyon and Clayoquot Slope—both monitored by ONC's cabled offshore observatory. [...]"
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. Some, like the northwest margin of Africa, were characterized by strong upwelling, but what might drive enhanced productivity on shelves not geographically suited for upwelling? [...]"
Authors: Christopher M. Lowery
On the effect of low oxygen concentrations on bacterial degradation of sinking particles
"In marine oxygen (O2) minimum zones (OMZs), the transfer of particulate organic carbon (POC) to depth via the biological carbon pump might be enhanced as a result of slower remineralisation under lower dissolved O2 concentrations (DO). In parallel, nitrogen (N) loss to the atmosphere through microbial processes, such as denitrification and anammox, is directly linked to particulate nitrogen (PN) export. [...]"
Source: Scientific Reports
Authors: Frédéric A. C. Le Moigne
Deep oceans may acidify faster than anticipated due to global warming
"Oceans worldwide are undergoing acidification due to the penetration of anthropogenic CO2 from the atmosphere. The rate of acidification generally diminishes with increasing depth. Yet, slowing down of the thermohaline circulation due to global warming could reduce the pH in the deep oceans, as more organic material would decompose with a longer residence time. [...]"
Source: Nature Climate Change
Authors: Chen-Tung Arthur Chen
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Investigating the impacts of treated effluent discharge on coastal water health (Visakhapatnam, SW coast of Bay of Bengal, India)
"The present study investigated the impacts of treated effluent discharge on physicochemical and biological properties of coastal waters from three pharmaceuticals situated along the coast of Visakhapatnam (SW Bay of Bengal). Seawater samples were collected (during the months of December 2013, March 2014 and April 2014) from different sampling locations (Chippada (CHP), Tikkavanipalem (TKP) and Nakkapalli (NKP)) at 0- and 30-m depths within 2-km radius (0.5 km = inner, 1 km = middle and 2 km = outer sampling circles) from the marine outfall points. [...]"
Source: Environmental Monitoring and Assessment
Authors: Aziz Ur Rahman Shaik et al.
Repeated storage of respired carbon in the equatorial Pacific Ocean over the last three glacial cycles
"As the largest reservoir of carbon exchanging with the atmosphere on glacial–interglacial timescales, the deep ocean has been implicated as the likely location of carbon sequestration during Pleistocene glaciations. Despite strong theoretical underpinning for this expectation, radiocarbon data on watermass ventilation ages conflict, and proxy interpretations disagree about the depth, origin and even existence of the respired carbon pool. [...]"
Authors: A.W. Jacobel
Source: Nature Communications
Oxygenation as a driver of the Great Ordovician Biodiversification Event
"The largest radiation of Phanerozoic marine animal life quadrupled genus-level diversity towards the end of the Ordovician Period about 450 million years ago. A leading hypothesis for this Great Ordovician Biodiversification Event is that cooling of the Ordovician climate lowered sea surface temperatures into the thermal tolerance window of many animal groups, such as corals. [...]"
Source: Nature Geoscience
Authors: Cole T. Edwards