scholarly journals Dissolved oxygen dynamic across the new-born interface of bottom water and sediment after dredging contaminated sediment

2018 ◽  
Vol 30 (6) ◽  
pp. 1518-1524 ◽  
Author(s):  
GU Xiaozhi ◽  
◽  
JIANG Weihua
Keyword(s):  
Dissolved Oxygen ◽  
Bottom Water ◽  
Contaminated Sediment ◽  
New Born ◽  
Water And Sediment ◽  
Oxygen Dynamic

Summer Bottom Water Dissolved Oxygen in Upper Narragansett Bay

2008 ◽  
pp. 325-347 ◽  
Author(s):  
Emily Saarman ◽  
Warren L. Prell ◽  
David W. Murray ◽  
Christopher F. Deacutis
Keyword(s):  
Dissolved Oxygen ◽  
Bottom Water ◽  
Narragansett Bay

scholarly journals The Relationship between Mollusks and Oxygen Concentrations in Todos Santos Bay, Baja California, Mexico

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
J. Gabriel Kuk-Dzul ◽  
Victoria Díaz-Castañeda
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Bottom Water ◽  
Organic Matter Content ◽  
Oxygen Depletion ◽  
Matter Content ◽  
The Other ◽  
Natural Conditions ◽  
The Relationship ◽  
Oxygen Concentrations

This study describes the relationship between mollusks, physicochemical properties of seawater, and sediments under natural conditions of low impact. Thirty-nine stations were sampled in October 1994 using a Van Veen grab (0.1 m−2). Temperature, salinity, and dissolved oxygen (DO) concentrations of bottom water were obtained with a CTD. Organic matter content and sediment grain analysis were determined. A total of 836 mollusks were collected. Gastropoda was the most abundant (52%) and diverse class with 27 genera, followed by Bivalvia with eight genera and Scaphopoda with only one genus. According to CCA analysis, dominant mollusks were significantly related with high DO concentrations.Donax,Natica,Acteocina,Bulla,Anachis,Odostomia, andCrucibulumcan be classified as sensitive genera because they were found mainly in high oxygen concentrations (3.1–5.6 mL L−1); on the other hand,Cardiomya,Nuculana,Laevicardium,Chione,Truncatella, andDentaliumcan be classified as tolerant genera (1.0–5.6 mL L−1). Todos Santos Bay hosts a diverse malacological fauna (36 genera); our results show that the dominant genera were mainly related to high dissolved oxygen concentrations. Mollusks can be a useful tool in environmental monitoring programs related with oxygen depletion in coastal areas.

Quantitative studies on the marine phycomycetes, chytrids and higher mycelial fungi of the upper Tay Estuary

1980 ◽  
Vol 78 (3-4) ◽  
pp. s57-s78
Author(s):  
Alwin Gaertner
Keyword(s):  
Bottom Water ◽  
Marine Fungi ◽  
Mycelial Fungi ◽  
Water Culture ◽  
Sediment Samples ◽  
Quantitative Studies ◽  
Water And Sediment ◽  
Pine Pollen ◽  
Water Bottom ◽  
Tay Estuary

SynopsisAt ten stations in the upper Tay Estuary, surface water, bottom water and sediment samples were taken on 25 March 1976, 5/6 May 1977, 11 April 1978 and 6 June 1978, and investigated quantitatively for the presence of lower marine fungi, chytrids and higher mycelial fungi by means of the water-culture baiting method with pine pollen. The distribution of fungi is discussed as a function of the physical characteristics of the estuary.

scholarly journals THE EQUIPMENT FOR PRECISE TEMPERATURE MONITORING

2019 ◽  
pp. 39-47
Author(s):  
S. A. Kazantsev ◽  
A. D. Duchkov
Keyword(s):  
Bottom Water ◽  
Temperature Monitoring ◽  
Water And Sediment ◽  
Tomsk Region

The article describes the modern version of the equipment for the autonomous temperature monitoring in boreholes and reservoirs. To characterize the capabilities of the equipment, the results of the long-term measurements of the temperature of Vasyugan swamp (Tomsk region) peatlands and the bottom (water and sediment) of lakes Baikal and Teletskoye are presented.

scholarly journals Detection of low bottom water oxygen concentrations in the North Sea; implications for monitoring and assessment of ecosystem health

2009 ◽  
Vol 6 (4) ◽  
pp. 8411-8453 ◽  
Author(s):  
N. Greenwood ◽  
E. R. Parker ◽  
L. Fernand ◽  
D. B. Sivyer ◽  
K. Weston ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
North Sea ◽  
Mixed Layer ◽  
Ecosystem Health ◽  
Bottom Water ◽  
Dissolved Oxygen Concentration ◽  
The North ◽  
The North Sea ◽  
Oxygen Concentrations

Abstract. This paper presents new results from high temporal resolution observations over two years (2007 and 2008) from instrumented moorings deployed in the central North Sea, at the Oyster Grounds and on the northern slope of Dogger Bank (North Dogger). The water column was stratified in the summer at both sites, leading to limited exchange of the water in the bottom mixed layer. Data from these moorings revealed the variable nature of summer oxygen depletion at the Oyster Grounds. The combination of in situ and ship-based measurements allowed the physical and biological conditions leading to decreasing dissolved oxygen concentrations in bottom water to be examined. The concentration of dissolved oxygen in the bottom water at both sites was observed to decrease throughout the summer period after the onset of stratification. Depleted dissolved oxygen concentration (6.5 mg l−1, 71% saturation) was measured at the North Dogger, a site which is not significantly influenced by anthropogenic nutrient inputs. Lower oxygen saturation (5.2 mg l−1, 60% saturation) was measured for short durations at the Oyster Grounds. Increasing bottom water temperature accounted for 55% of the decrease in dissolved oxygen concentration at the Oyster Grounds compared to 10% at North Dogger. Dissolved oxygen concentration in bottom water at the Oyster Grounds was shown to be strongly influenced by short term events including storm events and pulses of biomass input. In contrast, dissolved oxygen concentration in bottom water at the North Dogger reflected longer seasonal processes such as gradual temperature increases and a more steady supply of biomass to the bottom mixed layer. The differences between the study sites shows the need for an improved understanding of the mechanisms driving these processes if the use of oxygen in marine management and ensuring ecosystem health is to be meaningful and successful in the future. These observations provide greater understanding of the nature of the depletion in bottom oxygen concentration in the North Sea.

scholarly journals Detection of low bottom water oxygen concentrations in the North Sea; implications for monitoring and assessment of ecosystem health

2010 ◽  
Vol 7 (4) ◽  
pp. 1357-1373 ◽  
Author(s):  
N. Greenwood ◽  
E. R. Parker ◽  
L. Fernand ◽  
D. B. Sivyer ◽  
K. Weston ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
North Sea ◽  
Particulate Organic Matter ◽  
Ecosystem Health ◽  
Bottom Water ◽  
Dissolved Oxygen Concentration ◽  
The North ◽  
The North Sea

Abstract. This paper presents new results from high temporal resolution observations over two years (2007 and 2008) from instrumented moorings deployed in the central North Sea, at the Oyster Grounds and on the northern slope of Dogger Bank (North Dogger). The water column was stratified in the summer at both sites, leading to limited exchange of the water in the bottom mixed layer. Data from these moorings revealed the variable nature of summer oxygen depletion at the Oyster Grounds. The combination of in situ and ship-based measurements allowed the physical and biological conditions leading to decreasing dissolved oxygen concentrations in bottom water to be examined. In 2007 and 2008, the concentration of dissolved oxygen in the bottom water at both sites was observed to decrease throughout the summer period after the onset of stratification. Depleted dissolved oxygen concentration (6.5 mg l−1, 71% saturation) was measured at the North Dogger, a site which is not significantly influenced by anthropogenic nutrient inputs. Lower oxygen saturation (5.2 mg l−1, 60% saturation) was measured for short durations at the Oyster Grounds. The seasonal increase in bottom water temperature accounted for 55% of the decrease in dissolved oxygen concentration at the Oyster Grounds compared to 10% at North Dogger. Dissolved oxygen concentration in bottom water at the Oyster Grounds was shown to be strongly influenced by short term events including storms and pulses of particulate organic matter input. In contrast, dissolved oxygen concentration in bottom water at the North Dogger reflected longer seasonal processes such as a gradual temperature increase over the summer and a more steady supply of particulate organic matter to the bottom mixed layer. The differences between the study sites shows the need for an improved understanding of the mechanisms driving these processes if the use of oxygen in marine management and ensuring ecosystem health is to be meaningful and successful in the future. These high frequency observations provide greater understanding of the nature of the depletion in bottom oxygen concentration in the North Sea.

scholarly journals Mg/Ca and Mn/Ca ratios in benthic foraminifera: the potential to reconstruct past variations in temperature and hypoxia in shelf regions

2013 ◽  
Vol 10 (7) ◽  
pp. 5125-5138 ◽  
Author(s):  
J. Groeneveld ◽  
H. L. Filipsson
Keyword(s):  
Dissolved Oxygen ◽  
Trace Metal ◽  
Benthic Foraminifera ◽  
Bottom Water ◽  
Oxygen Depletion ◽  
Open Ocean ◽  
Low Oxygen ◽  
Saturation State ◽  
Bottom Water Temperature ◽  
Fish And Shellfish

Abstract. Shelf and coastal regions are exceptionally important for many countries as they provide the main habitat for many economically important fish and shellfish species. With ongoing climate change and human-induced eutrophication the shelf regions are especially affected, resulting in increased temperatures and stratification as well as oxygen depletion of the bottom waters. In order to be able to predict the magnitude of these changes in the future, it is necessary to study how they varied in the past. Commonly used foraminiferal climate and environmental proxies, e.g., stable isotopes and trace metal/Ca ratios, that are applied in open-ocean settings are not necessarily applicable in shelf regions, either as faunas are significantly different or as conditions can change much faster compared to the open ocean. In this study we explore the use of Mg/Ca as paleothermometer and Mn/Ca as a potential proxy for changing dissolved oxygen conditions in bottom water on the benthic foraminifera Bulimina marginata and Globobulimina turgida. Living specimens were collected from the Skagerrak and the Gullmar Fjord (SW Sweden); the latter is hypoxic for several months a year. As the specimens were alive when collected, we assume it unlikely that any diagenetic coatings have already significantly affected the trace metal/Ca ratios. The Mg/Ca ratios are similar to previously published values but display much larger variation than would be expected from the annual temperature change of less than 2 °C. An additional impact of the difference in the calcite saturation state between the Skagerrak and the Gullmar Fjord could explain the results. Mn/Ca ratios from G. turgida can potentially be related to variations in dissolved oxygen of the habitat where the foraminifera calcify. Samples from the Skagerrak display increased Mn/Ca in specimens that lived deeper in the sediment than those that lived near the surface. G. turgida samples from the low-oxygen Gullmar Fjord showed significantly increased Mn/Ca, being highest when bottom water dissolved oxygen was at a minimum. Our study suggests that trace metal/Ca ratios in benthic foraminifera from shelf regions have the potential to record past variations in bottom water temperature and dissolved oxygen concentrations, but an additional impact of the inorganic carbonate chemistry cannot be excluded.

Influence of Physical Forcing on Bottom-Water Dissolved Oxygen within Caloosahatchee River Estuary, Florida

2010 ◽  
Vol 136 (10) ◽  
pp. 1032-1044 ◽  
Author(s):  
Meng Xia ◽  
Paul M. Craig ◽  
Blake Schaeffer ◽  
Andrew Stoddard ◽  
Zhijun Liu ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Bottom Water ◽  
River Estuary ◽  
Physical Forcing ◽  
Caloosahatchee River

Effects of bottom water dissolved oxygen variability on copper and lead fractionation in the sediments across the oxygen minimum zone, western continental margin of India

2016 ◽  
Vol 566-567 ◽  
pp. 1052-1061 ◽  
Author(s):  
Parthasarathi Chakraborty ◽  
Sucharita Chakraborty ◽  
Saranya Jayachandran ◽  
Ritu Madan ◽  
Arindam Sarkar ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Continental Margin ◽  
Bottom Water ◽  
Oxygen Minimum Zone ◽  
Minimum Zone ◽  
Oxygen Minimum
Sign in / Sign up

Export Citation Format

Share Document