scholarly journals Using small-scale measurements to estimate hypolimnetic oxygen depletion in a deep lake

2017 ◽  
Vol 63 (S1) ◽  
pp. S54-S67 ◽  
Author(s):  
Robert Schwefel ◽  
Thomas Steinsberger ◽  
Damien Bouffard ◽  
Lee D. Bryant ◽  
Beat Müller ◽  
...  
Keyword(s):  
Oxygen Depletion ◽  
Small Scale ◽  
Deep Lake ◽  
Hypolimnetic Oxygen

Rates of oxygen-depletion in granular Lambeth Group strata and evidence for barometric pumping

2020 ◽  
Vol 53 (4) ◽  
pp. 645-654
Author(s):  
T.G. Newman ◽  
R.C. Ghail
Keyword(s):  
Laboratory Experiments ◽  
Health And Safety ◽  
Barometric Pressure ◽  
Oxygen Depletion ◽  
Small Scale ◽  
Confined Space ◽  
Underground Construction ◽  
Barometric Pumping ◽  
Ground Investigation ◽  
Short Time

Laboratory experiments have been performed to demonstrate significant levels of oxygen depletion within samples of Upnor Formation of the Lambeth Group deposits. These have been used to explain the reasons for several incidences of confined space hypoxia during underground construction within the stratum beneath London. Further investigation, using a relatively small-scale field pump-out test, revealed the rapid effects of dewatering on the generation of hypoxic gas (within the ground) and that the amount of oxygen falls to fatal levels within a very short time after commencement of pumping. Monitoring of boreholes during ground investigation for the Thames Tideway Tunnel has indicated barometric control on the release of hypoxic gas from installations within granular deposits of the Lambeth Group, namely the Upnor Formation, as well as channel sand deposits within the Laminated Beds. In these, reduced levels of oxygen coincide with low and/or falling barometric pressure. Continuous 24-hour monitoring demonstrates that the reduction is almost instantaneous and has serious implications for the Health and Safety of underground construction personnel.

Vertical Transport of Oxygen into the Hypolimnion of Lakes

1987 ◽  
Vol 44 (4) ◽  
pp. 852-858 ◽  
Author(s):  
R. J. Cornett ◽  
F. H. Rigler
Keyword(s):  
Heat Budget ◽  
Eddy Diffusivity ◽  
Oxygen Depletion ◽  
Vertical Transport ◽  
Oxygen Deficit ◽  
Eddy Diffusivities ◽  
Oxygen Gradients ◽  
Hypolimnetic Oxygen ◽  
Depletion Rate ◽  
Flux Parameter

Rates of vertical transport of oxygen into the hypolimnion were calculated by multiplying the vertical eddy diffusivity coefficients, determined from the heat budget, by the measured gradients in oxygen concentration. In 12 lakes, transport ranged from 0 to 70 mg O2∙m−2∙d−1 and was insensitive to the depth defining the upper boundary of the hypolimnion. Oxygen was transported into the hypolimnion of lakes with a thinner hypolimnion and out of the hypolimnion of lakes with a thick hypolimnion. Transport averaged 4% of the measured total rate of hypolimnetic oxygen depletion and < 10% of the depletion rate in individual strata. Pooling these results with published estimates of oxygen gradients and eddy diffusivities suggests that in lakes with different trophic status (phosphorus levels 4–100 μg∙L−1) and size (areas from 0.4 to 70 km2), vertical oxygen transport accounts for less than 15% of the hypolimnetic oxygen deficit. Oxygen depletion models will gain relatively little precision by including a vertical transport flux parameter.

“Dead Zone” dynamics in Lake Erie: the importance of weather and sampling intensity for calculated hypolimnetic oxygen depletion rates

2010 ◽  
Vol 73 (2) ◽  
pp. 289-304 ◽  
Author(s):  
Joseph D. Conroy ◽  
Leon Boegman ◽  
Hongyan Zhang ◽  
William J. Edwards ◽  
David A. Culver
Keyword(s):  
Lake Erie ◽  
Dead Zone ◽  
Oxygen Depletion ◽  
Sampling Intensity ◽  
Hypolimnetic Oxygen

scholarly journals Relationship between areal hypolimnetic oxygen depletion rate and the trophic state of five lakes in northern Poland

2011 ◽  
Vol 11 (4) ◽  
pp. 135-142 ◽  
Author(s):  
Dariusz Borowiak ◽  
Kamil Nowiński ◽  
Jacek Barańczuk ◽  
Włodzimierz Marszelewski ◽  
Rajmund Skowron ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Trophic State ◽  
Oxygen Depletion ◽  
Water Transparency ◽  
Morphological Data ◽  
Lake Productivity ◽  
Stratified Lakes ◽  
Northern Poland ◽  
Hypolimnetic Oxygen ◽  
Depletion Rate

Relationship between areal hypolimnetic oxygen depletion rate and the trophic state of five lakes in northern PolandThe oxygen content in a lake is a fundamental factor in lake ecology. In stratified lakes, deep waters are isolated from the atmosphere for several months during the summer; therefore, oxygen (substantially consumed by biological and chemical processes at this time) cannot be replaced before the autumnal mixing period. Hypolimnetic oxygen depletion has been considered an indicator of lake productivity since the early twentieth century. Many recent studies have been in opposition to this view by showing that the areal hypolimnetic oxygen depletion rate (AHOD) is poorly correlated with seston biomass and/or phosphorus concentration. The objective of this study is to show relationships between the mean values of total phosphorus (TP), total nitrogen (TN), chlorophyll a, and water transparency (Secchi disk depth, SDD) during the thermal stratification formation period and the AHOD rate. Hypolimnetic oxygen conditions in five dimictic lakes in northern Poland were examined in 2009 and 2010. Two of them were studied in the previous year. Monthly oxygen profiles taken from April to August, midsummer temperature profiles, and morphological data of the lakes were used to determine the AHOD rate. Standard water quality parameters such as concentrations of chlorophyll a, TP, and TN, as well as water transparency measured at the same time were used to calculate the trophic state indices (TSI) according to the Carlson-type formulas. On the basis of the collected data it is shown that AHOD is highly correlated with the TSI value for chlorophyll a, and poorly correlated with the TSI values for water transparency and phosphorus content. The best correlation between AHOD and TSI has been found for chlorophyll a (r2=0.702; p<0.001), as well as for overall TSI, determined by averaging separate component indices (r2=0.826; p<0.000). No correlation was found between AHOD and total nitrogen concentration. The research also confirmed previous observations, which pointed to a significant role of the hypolimnion depth in increasing oxygen deficits.

scholarly journals Long-term development of hypolimnetic oxygen depletion rates in the large Lake Constance

AMBIO ◽  
2017 ◽  
Vol 46 (5) ◽  
pp. 554-565 ◽  
Author(s):  
Justin Rhodes ◽  
Harald Hetzenauer ◽  
Marieke A. Frassl ◽  
Karl-Otto Rothhaupt ◽  
Karsten Rinke
Keyword(s):  
Oxygen Depletion ◽  
Lake Constance ◽  
Large Lake ◽  
Hypolimnetic Oxygen

Zoobenthic Distribution and Biomass in the Turkey Lakes

1988 ◽  
Vol 45 (S1) ◽  
pp. s107-s114 ◽  
Author(s):  
R. M. Dermott
Keyword(s):  
Littoral Zone ◽  
Large Population ◽  
Benthic Fauna ◽  
Oxygen Depletion ◽  
Fish Production ◽  
Chemical Gradient ◽  
Top Predators ◽  
Hypolimnetic Oxygen ◽  
Turkey Lakes Watershed ◽  
Predatory Insects

The composition of the benthic fauna in the four oligotrophic lakes of the Turkey Lakes Watershed was dependent on the absence offish, depth, and hypolimnetic oxygen concentrations, rather than the chemical gradient in the watershed. Biomass in the littoral zone was greatest in the fishless upper lake of the watershed (0.35 g∙m−2), dominated by amphipods and predatory insects, which replaced fish as top predators in the lake. The shallowest lake (Wishart) had the lowest lakewide biomass (199 g∙ha−1) and estimated production of the four lakes, in spite of having the greatest algal and fish production in the watershed. The biomass present below 2 m was greater in the lower two lakes, dominated by the Chironomidae. Little Turkey Lake had the greatest area weighted lakewide biomass (843 g∙ha−1) and estimated production, as a result of a large population of Chironomus spp. in the hypolimnion. Batchawana Lake, the upper lake in the watershed, had the lowest benthic populations due to severe oxygen depletion in the hypolimnion.

Oxygen Depletion in Lake Erie: Has There Been Any Change?

1980 ◽  
Vol 37 (1) ◽  
pp. 72-80 ◽  
Author(s):  
M. N. Charlton
Keyword(s):  
High Temperatures ◽  
Lake Erie ◽  
Oxygen Depletion ◽  
General Level ◽  
Central Basin ◽  
Small Lakes ◽  
Hypolimnetic Oxygen ◽  
Depletion Rate

A new analysis of hypolimnetic oxygen in Central Lake Erie indicates that historic increases in the apparent depletion were not as great as formerly believed. The differences that did occur were mostly related to variations in hypolimnion thickness. Changes, if any, in the oxygen depletion rate due to eutrophication are as yet too small to be recognized. Present-day oxygen depletion rates, when corrected for the relatively high temperatures in Lake Erie, are within the range thought to be indicative of mesotrophy in small lakes. The general level of oxygen depletion observed in the Central Basin of Lake Erie is expected on the basis of morphology alone.Key words: Lake Erie, oxygen, hypolimnion, oxygen depletion, trend

Pelagic food web interactions and hypolimnetic oxygen depletion: Results from experimental enclosures and lakes

1990 ◽  
Vol 52 (2) ◽  
pp. 144-155 ◽  
Author(s):  
Asit Mazumder ◽  
D. J. McQueen ◽  
W. D. Taylor ◽  
D. R. S. Lean
Keyword(s):  
Food Web ◽  
Oxygen Depletion ◽  
Food Web Interactions ◽  
Pelagic Food Web ◽  
Hypolimnetic Oxygen
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