scholarly journals Susane, a device for sampling chemical gradients in the benthic water column

2019 ◽  
Author(s):  
Joël Knoery ◽  
Daniel Cossa ◽  
Bastien Thomas ◽  
Germain Gregory ◽  
Sylvain Rigaud
Keyword(s):  
Water Column ◽  
Chemical Gradients

scholarly journals Distribution of bacterial populations in a stratified fjord (mariager fjord, denmark) quantified by in situ hybridization and related to chemical gradients in the water column

1996 ◽  
Vol 62 (10) ◽  
pp. 3914-3914
Author(s):  
N B Ramsing ◽  
H Fossing ◽  
T G Ferdelman ◽  
F Andersen ◽  
B Thamdrup
Keyword(s):  
In Situ Hybridization ◽  
Aluminum Oxide ◽  
Pore Size ◽  
Water Column ◽  
Bacterial Populations ◽  
Chemical Gradients

Volumn 62, no. 4, p. 1392, lines 37 and 38: "Aluminum oxide filters (0.2 mm pore size; Anopore; Millipore GmbH, Eschborn, Germany)" should read "Aluminum oxide filters (0.2 (mu)m pore size; Anopore; Whatman, Inc., Clifton, N.J.)." Page 1403, reference 15: "Fenchel, T." should read "Fenchel, T., L. D. Kristensen, and L. Rasmussen." [This corrects the article on p. 1391 in vol. 62.].

scholarly journals Biogeochemical Niche of Magnetotactic Cocci Capable of Sequestering Large Polyphosphate Inclusions in the Anoxic Layer of the Lake Pavin Water Column

2022 ◽  
Vol 12 ◽  
Author(s):  
Cécile C. Bidaud ◽  
Caroline L. Monteil ◽  
Nicolas Menguy ◽  
Vincent Busigny ◽  
Didier Jézéquel ◽  
...  
Keyword(s):  
Water Column ◽  
Light And Electron Microscopy ◽  
Environmental Parameters ◽  
Aqueous System ◽  
Calcium Carbonates ◽  
Chemical Gradients ◽  
Anoxic Layer ◽  
Geochemical Analyses ◽  
Lake Pavin ◽  
Biogeochemical Niche

Magnetotactic bacteria (MTB) are microorganisms thriving mostly at oxic–anoxic boundaries of aquatic habitats. MTB are efficient in biomineralising or sequestering diverse elements intracellularly, which makes them potentially important actors in biogeochemical cycles. Lake Pavin is a unique aqueous system populated by a wide diversity of MTB with two communities harbouring the capability to sequester not only iron under the form of magnetosomes but also phosphorus and magnesium under the form of polyphosphates, or calcium carbonates, respectively. MTB thrive in the water column of Lake Pavin over a few metres along strong redox and chemical gradients representing a series of different microenvironments. In this study, we investigate the relative abundance and the vertical stratification of the diverse populations of MTB in relation to environmental parameters, by using a new method coupling a precise sampling for geochemical analyses, MTB morphotype description, and in situ measurement of the physicochemical parameters. We assess the ultrastructure of MTB as a function of depth using light and electron microscopy. We evidence the biogeochemical niche of magnetotactic cocci, capable of sequestering large PolyP inclusions below the oxic–anoxic transition zone. Our results suggest a tight link between the S and P metabolisms of these bacteria and pave the way to better understand the implication of MTB for the P cycle in stratified environmental conditions.

scholarly journals Larval fish assemblages from channels and fjords of south Pacific Patagonia: effects of environmental conditions

2018 ◽  
Vol 53 ◽  
pp. 39 ◽  
Author(s):  
Gissella Castillo-Hidalgo ◽  
Mauricio F. Landaeta ◽  
Eduardo Anaya-Godínez ◽  
Claudia A. Bustos
Keyword(s):  
Water Column ◽  
Environmental Conditions ◽  
Fish Assemblages ◽  
Environmental Variability ◽  
Larval Fish ◽  
The Other ◽  
Southern Chile ◽  
Chemical Gradients ◽  
Temperature Depth ◽  
Patagonian Fjords

Chilean Patagonian fjords are characterized by strong stratification and chemical gradients which influence the ichthyoplankton distribution and abundance. Plankton samples were collected through bongo net oblique tows in 40 stations from onboard a bio-oceanographic cruise took place in inner fjords of southern Chile (47° to 51°S). Water column physical data were obtained with a conductivity-temperature-depth profiler (CTD) and turbidity was measured with a portable turbidimeter from 0 to 100 m depth. Stations were distributed by three zones: oceanic, channels and continental waters. A total of 1424 larvae were collected, representing 21 families. Dominant taxa were Maurolicus parvipinnis (31%), Sebastes oculatus (12%), Merluccius australis (11%), Lampanyctodes hectoris (10%), and Bathylagichthys parini (8%). Most of the environmental variability was determined by salinity, mainly in the area where continental waters are discharged. The water column in the oceanic zone presented mixed waters dominated by the myctophid L. hectoris and the sternoptychid M. parvipinnis. No significant effect of turbidity gradients on larval fish assemblages was evident during spring. The channel zone was both more saline, and density stratified with less turbidity, and lower abundance of species. Two ichthyoplanktonic assemblages were evident, one living in oceanic waters, and the other from channels and inner zones.

scholarly journals Distribution of bacterial populations in a stratified fjord (mariager fjord, denmark) quantified by in situ hybridization and related to chemical gradients in the water column

1996 ◽  
Vol 62 (10) ◽  
pp. 3915-3915
Author(s):  
N B Ramsing ◽  
H Fossing ◽  
T G Ferdelman ◽  
F Andersen ◽  
B Thamdrup
Keyword(s):  
In Situ Hybridization ◽  
Vertical Distribution ◽  
Water Column ◽  
Recent Article ◽  
Bacterial Populations ◽  
Chemical Gradients ◽  
The Vertical Distribution

Volume 62, no. 4, p. 1391-1404: after publication of this article, it was brought to the attention of the authors that a more extensive treatment of the hydrodynamics of Mariager Fjord and the vertical distribution of bacteria and protozoa therein was published in a recent article by Fenchel et al. This work contains important information about the studied ecosystem, but unfortunately, the existence of this work was realized only after publication of our article. Thus, the following reference should have been cited in our article: [This corrects the article on p. 1391 in vol. 62.].

Comparison of the performance of oscillating water column devices based on arrangements of water columns

2020 ◽  
Vol 14 (3) ◽  
pp. 7082-7093
Author(s):  
Jahirwan Ut Jasron ◽  
Sudjito Soeparmani ◽  
Lilis Yuliati ◽  
Djarot B. Darmadi
Keyword(s):  
Wave Propagation ◽  
Water Column ◽  
Water Depth ◽  
Graphical Form ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Power Absorption ◽  
Water Columns ◽  
Single Column ◽  
Parallel Arrangement

The hydrodynamic performance of oscillating water column (OWC) depends on the depth of the water, the size of the water column and its arrangement, which affects the oscillation of the water surface in the column. An experimental method was conducted by testing 4 water depths with wave periods of 1-3 s. All data recorded by the sensor is then processed and presented in graphical form. The research focused on analyzing the difference in wave power absorption capabilities of the three geometric types of OWC based on arrangements of water columns. The OWC devices designed as single water column, the double water column in a series arrangement which was perpendicular to the direction of wave propagation, and double water column in which the arrangement of columns was parallel to the direction of wave propagation. This paper discussed several factors affecting the amount of power absorbed by the device. The factors are the ratio of water depth in its relation to wavelength (kh) and the inlet openings ratio (c/h) of the devices. The test results show that if the water depth increases in the range of kh 0.7 to 0.9, then the performance of the double chamber oscillating water column (DCOWC) device is better than the single chamber oscillating water column (SCOWC) device with maximum efficiency for the parallel arrangement 22,4%, series arrangement 20.8% and single column 20.7%. However, when referring to c/h, the maximum energy absorption efficiency for a single column is 27.7%, double column series arrangement is 23.2%, and double column parallel arrangement is 29.5%. Based on the results of the analysis, DCOWC devices in parallel arrangement showed the ability to absorb better wave power in a broader range of wave frequencies. The best wave of power absorption in the three testing models occurred in the wave period T = 1.3 seconds.

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