An approach for extraction, characterization and quantitation of microplastic in natural marine snow using Raman microscopy

2017 ◽  
Vol 9 (9) ◽  
pp. 1470-1478 ◽  
Author(s):  
Shiye Zhao ◽  
Meghan Danley ◽  
J. Evan Ward ◽  
Daoji Li ◽  
Tracy J. Mincer
Keyword(s):  
Water Column ◽  
Raman Microscopy ◽  
Marine Water ◽  
Marine Snow ◽  
Particulate Carbon ◽  
Sea Floor ◽  
Predominant Form

Marine snow is a predominant form of sinking particulate carbon in the marine water column and represents a mechanism for transporting microplastics to the sea floor.

scholarly journals Bacteria-Oil Microaggregates Are an Important Mechanism for Hydrocarbon Degradation in the Marine Water Column

mSystems ◽  
2021 ◽  
Author(s):  
Amanda M. Achberger ◽  
Shawn M. Doyle ◽  
Makeda I. Mills ◽  
Charles P. Holmes ◽  
Antonietta Quigg ◽  
...  
Keyword(s):  
Water Column ◽  
Biological Response ◽  
Deepwater Horizon ◽  
Marine Water ◽  
Hydrocarbon Degradation ◽  
Marine Snow ◽  
Event Uncertainty

Vast quantities of oil-associated marine snow (MOS) formed in the water column as part of the natural biological response to the Deepwater Horizon drilling accident. Despite the scale of the event, uncertainty remains about the mechanisms controlling MOS formation and its impact on the environment.

scholarly journals Missing links in the study of solute and particle exchange between the sea floor and water column

2020 ◽  
Vol 77 (5) ◽  
pp. 1602-1616 ◽  
Author(s):  
Saskia Rühl ◽  
Charlie Thompson ◽  
Ana M Queirós ◽  
Stephen Widdicombe
Keyword(s):  
Water Column ◽  
Current Knowledge ◽  
Anthropogenic Impacts ◽  
Future Research ◽  
Sea Floor ◽  
Marine Habitats ◽  
Exchange Processes ◽  
Ecosystem Level ◽  
Particle Exchange

Abstract Exchanges of solutes and solids between the sea floor and water column are a vital component of ecosystem functioning in marine habitats around the globe. This review explores particle and solute exchange processes, the different mechanisms through which they interact at the ecosystem level, as well as their interdependencies. Solute and particle exchange processes are highly dependent on the characteristics of the environment within which they takes place. Exchange is driven directly by a number of factors, such as currents, granulometry, nutrient, and matter inputs, as well as living organisms. In turn, the occurrence of exchanges can influence adjacent environments and organisms. Major gaps in the present knowledge include the temporal and spatial variation in many of the processes driving benthic/pelagic exchange processes and the variability in the relative importance of individual processes caused by this variation. Furthermore, the accurate assessment of some anthropogenic impacts is deemed questionable due to a lack of baseline data and long-term effects of anthropogenic actions are often unknown. It is suggested that future research should be transdisciplinary and at ecosystem level wherever possible and that baseline surveys should be implemented and long-term observatories established to fill the current knowledge gaps.

Implementation of a multipurpose Arctic Ocean Observing System

2020 ◽  
Author(s):  
Stein Sandven ◽  
Hanne Sagen ◽  
Agnieszka Beszczynska-Möller ◽  
Peter Vo ◽  
Marie-Noelle Houssais ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Water Column ◽  
The Arctic ◽  
Sea Floor ◽  
Acoustic Thermometry ◽  
The Arctic Ocean ◽  
Global Coverage ◽  
Cable Systems ◽  
Ocean Observing ◽  
Observing Systems

<p>The central Arctic Ocean is one of the least observed oceans in the world. This ice-covered region is challenging for ocean observing with respect to technology, logistics and costs. Many physical, biogeochemical, biological, and geophysical processes in the water column and sea floor under the sea ice are difficult to observe and therefore poorly understood. Today, there are technological advances in platforms and sensors for under-ice observation, which offer possibilities to install and operate sustained observing infrastructures in the Arctic Ocean. The goal of the INTAROS project is to develop integrated observing systems in the Arctic, including improvement of data sharing and dissemination to various user groups. INTAROS supports a number of systems providing data from the ocean in delayed mode as well as in near-real time mode, but only a few operate in the ice-covered areas.</p><p>Autonomous observing platforms used in the ice-free oceans such as Argo floats, gliders, and autonomous surface vehicles cannot yet be used operationally in ice-covered Arctic regions. The limitation is because the sea ice prevents these underwater platforms from reaching the surface for satellite communication and geopositioning. To improve the Arctic Ocean Observing capability OceanObs19 recommended ‘to pilot a sustained multipurpose acoustic network for positioning, tomography, passive acoustics, and communication in an integrated Arctic Observing System, with eventual transition to global coverage’. Acoustic networks have been used locally and regionally in the Arctic for underwater acoustic thermometry, geo-positioning for floats and gliders, and passive acoustic. The Coordinated Arctic Acoustic Thermometry Experiment (CAATEX) is a first step toward developing a basin-scale multipurpose acoustic network using modern instrumentation.</p><p>To provide secure data delivery, submarine cables are needed either as dedicated cabled observatories or as hybrid cable systems (sharing the cable infrastructure between science and commercial telecommunications), or both combined. Several large-scale cabled observatories existing coastal areas in world oceans, but none on the Arctic Ocean. At OceanObs19 it was recommended to transition (telecom+sensing) SMART subsea cable systems from present pilots to trans-ocean implementation, to address climate, ocean circulation, sea level, tsunami and earthquake early warning, ultimately with global coverage. Cabled observatories, either stand alone or branching from a hybrid system, could provide power and real time communication to support connected water column moorings and sea floor instrumentation as well as docking mobile platforms. Subsea cable developers are looking into the possibility to deploy a communication cable across the Arctic Ocean from Europe to Asia, because this offers a much shorter route compared to the terrestrial cables.</p><p> An international consortium of leading scientists in ocean observing with experience in state-of-the-art technologies on platforms, sensors, subsea cable technology, acoustic communication and data transmission plan to establish a project to implement and test the system based on experience from the CAATEX experiment and other Arctic observing system experiments. The INTAROS project is presently developing a Roadmap for an integrated Arctic Observing System, where multipurpose ocean observing systems will be one component.</p>

scholarly journals A reassessment of ‘<i>Globigerina bathoniana</i>’ Pazdrowa, 1969 and the palaeoceanographic significance of Jurassic planktic foraminifera from southern Poland

2012 ◽  
Vol 31 (2) ◽  
pp. 97-109 ◽  
Author(s):  
Malcolm B. Hart ◽  
Wendy Hudson ◽  
Christopher W. Smart ◽  
Jarosław Tyszka
Keyword(s):  
Water Column ◽  
Central Europe ◽  
Middle Jurassic ◽  
The Other ◽  
Carbonate Sediments ◽  
Calcareous Nannofossils ◽  
Planktic Foraminifera ◽  
Geological Record ◽  
Sea Floor ◽  
Southern Poland

Abstract. ‘Globigerina Ooze’, Foraminiferal Ooze or Carbonate Ooze as it is now known, is a widespread and highly characteristic sediment of the modern ocean system. Comparable sediments are much less common in the geological record although, as we describe here, a number of Middle Jurassic carbonate sediments with distinctive assemblages from Central Europe fulfil many of the criteria. One important component of these assemblages in the Middle Jurassic is ‘Globigerina bathoniana’ Pazdrowa, 1969, first described from the Bathonian sediments near Ogrodzieniec (Poland). The generic assignment of this species and other coeval Jurassic taxa is discussed. This species and many of the other early planktic foraminifera evolved in the Aragonite ll Ocean, together with the other two oceanic carbonate producers: the calcareous nannofossils and the calcareous dinoflagellates. The preservation of carbonate sediments with abundant planktic foraminifera on the sea floor indicates that, by the mid-Jurassic, the carbonate/aragonite compensation depths (and associated lysoclines) must have developed in the water column.

Methylmercury production in the marine water column

Nature ◽  
1981 ◽  
Vol 290 (5803) ◽  
pp. 243-244 ◽  
Author(s):  
G. Topping ◽  
I. M. Davies
Keyword(s):  
Water Column ◽  
Marine Water ◽  
Methylmercury Production

scholarly journals Efficiency of the silicate pump at a coastal oligotrophic site in the Mediterranean Sea

2005 ◽  
Vol 2 (3) ◽  
pp. 551-580 ◽  
Author(s):  
K. Leblanc ◽  
B. Quéguiner ◽  
P. Raimbault ◽  
N. Garcia
Keyword(s):  
Water Column ◽  
Biogenic Silica ◽  
High Efficiency ◽  
Eastern Mediterranean ◽  
Seasonal Pattern ◽  
Particulate Material ◽  
Particulate Carbon ◽  
Organic C ◽  
Gulf Of Lions ◽  
Organic Carbon Flux

Abstract. A one-year survey of the sedimenting particulate material was conducted at the SOFi site located on the edge of the continental slope in the Gulf of Lions (Northwestern Mediterranean) between September 1999 and December 2000. The main focus of this paper was to investigate the seasonal pattern of particulate biogenic silica (BSi) sedimentation fluxes in comparison with the particulate carbon fluxes and establish annual budgets of Si and C export. The pattern of the downward flux of BSi was partly typical with increased daily sedimentation rates during spring followed by smaller peaks during summer. However, an unusual sedimentation event was recorded in the bottom trap in February before the spring thermal stratification occurred, and represented 37% of the annual BSi mass flux. The total annual BSi flux at the SOFi site was estimated from the bottom trap and amounted to 86.8 mmol Si m-2 y-1, while the organic carbon flux amounted to 154.9 mmol C m-2 y-1. The overall efficiency of C export to depth compared to surface primary production budgets was low (3%) and similar to values found for oligotrophic regions of the Eastern Mediterranean. On the other hand, we documented a very high efficiency of the Si export at the SOFi site, with 62% of the Si produced in the surface layer exported to the bottom trap. The excellent correlation between BSi and particulate organic C (POC) in the bottom trap further indicates that the bulk of the organic matter is transferred to depth in association with diatoms. However, the main fraction of the C produced by phytoplankton is lost in the water column through oxidation or metabolisation, while biogenic silica is more efficiently transferred to depth. This strong Si/C decoupling with depth is likely to be the cause of the spring depletion of silicic acid over the entire water column which was observed by mid-April in a companion study (Leblanc et al., 2003) and may cause a severe Si limitation of the diatom spring bloom in this oligotrophic region of the Gulf of Lions.

scholarly journals Sedimentology of the grounding zone of the Kamb Ice Stream, Siple Coast, West Antarctica

2021 ◽  
Author(s):  
◽  
Theo Calkin
Keyword(s):  
Water Column ◽  
Transition Zone ◽  
Video Data ◽  
Hot Water ◽  
Sea Floor ◽  
The Core ◽  
Ice Stream ◽  
Grounding Line ◽  
Core Site ◽  
Kamb Ice Stream

<div>The grounding line of the Siple Coast incorporates six major ice streams, which together drain around a third of the West Antarctic Ice Sheet. Previously, the ~2000 km-long feature had only been sampled and directly observed at Whillans Ice Stream. This thesis examines glaciomarine sediment and processes operating at the presently stagnant Kamb Ice Stream (KIS) grounding zone ~3.3 km seaward of the modern grounding line (Lat. -82.78, Long. -155.16), where the ice is 590 m thick and overlies a 30 m thick water column. KIS-GZ is the planned site for a deep drilling project in 2023. The sea floor was accessed using a hot water drill in the 2019/20 Antarctic field season. A remotely operated submersible (‘Icefin’) was deployed under the ice shelf, which provided 800 m of sea floor video toward the grounding line. A small number of short (~0.6 m) gravity cores were collected from the seafloor, one of which was examined in this study. <br></div><div><br></div><div>The Icefin video imagery was processed using Structure-from-Motion (SfM) software, enabling the identification of two previously unrecognised sea floor sedimentary facies. One is defined by ubiquitous cm-scale ripples in fine-medium sand, where the ripples are aligned with the prevailing tidal currents flowing parallel to the grounding line. Observed current speeds are too low for the ripples to be generated under the modern oceanographic regime. The second facies is defined by abundant dropstones in mediumcoarse sand. A transition zone separates the two facies. Previously unidentified decimetre-scale bedforms are present in the transition zone and near the borehole.</div><div><br></div><div>The lithological, geochemical, and microfossil properties of the gravity core were analysed. The core sediment is sandy diamicton with weak stratification defined by decimetre-scale changes in clast abundance. Mineral counts, zircon ages, Nd/Sr isotopes, and an immature composition indicate this sediment is sourced within the Kamb catchment. The core also contains reworked late Oligocene-late Miocene diatoms. Quaternary diatoms are absent. Ramped pyrolysis radiocarbon dating was attempted on 19 carbon fractions obtained from samples at four depths. Two pyrolysis fractions yielded ages of 31.5-33.2 ka, while the rest did not contain measurable radiocarbon. This likely reflects the reworking of radiocarbon-dead material into the sediment and can only be considered a maximum age for deposition.</div><div><br></div><div>Together, the sediment and video data suggest deposition of the sea floor sediment at the core site occurred subsequent to the stagnation of KIS ~160 years ago. I assume that sediment concentrations are relatively uniform along the length of the ice stream and calculate that up to ~2.7 m of diamicton was rapidly deposited at the core site as the grounding line retreated and englacial sediment melted out and settled through the water column. Accumulation in recent decades has been comparatively low. During the period of reduced sedimentation, the sea floor diamicton has been reworked to varying degrees to form ripples and winnowed lag deposits, resulting in a textural patchwork at km scale.</div>

The comparative fate of dinosterol and cholesterol in copepod feeding: Implications for a conservative molecular biomarker in the marine water column

1989 ◽  
Vol 14 (6) ◽  
pp. 635-641 ◽  
Author(s):  
H.Rodger Harvey ◽  
Sean C.M. O'Hara ◽  
Geoffrey Eglinton ◽  
Eric D.S. Corner
Keyword(s):  
Water Column ◽  
Marine Water ◽  
Molecular Biomarker

Microbial transformation of jellyfish organic matter affects the nitrogen cycle in the marine water column — A Black Sea case study

2016 ◽  
Vol 475 ◽  
pp. 19-30 ◽  
Author(s):  
Tinkara Tinta ◽  
Tjaša Kogovšek ◽  
Valentina Turk ◽  
Tamara A. Shiganova ◽  
Alexander S. Mikaelyan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Black Sea ◽  
Nitrogen Cycle ◽  
Microbial Transformation ◽  
Marine Water
Sign in / Sign up

Export Citation Format

Share Document