Influence of oxygen concentration on the distribution of Mysis relicta Lovén in a eutrophic temperate lake

1987 ◽  
Vol 65 (11) ◽  
pp. 2646-2650 ◽  
Author(s):  
R. K. Sherman ◽  
D. C. Lasenby ◽  
L. Hollett

The lower depth limit of a Mysis population in Crystal Lake, southern Ontario, gradually moved upward through the summer stagnation period, generally following a position just above the 1.0 mg/L dissolved oxygen isopleth. Mysis held in bioassay chambers demonstrated a 16-h LC50 value of 1.0 mg dissolved oxygen/L. Avoidance chamber experiments revealed that Mysis could detect and move away from areas of low dissolved oxygen concentrations. It is suggested that Mysis, which has been used as an indicator of oligotrophic conditions, could survive in a mesotrophic or eutrophic lake that undergoes oxygen depletion in the hypolimnion by moving upward in the water column.

1980 ◽  
Vol 31 (5) ◽  
pp. 589 ◽  
Author(s):  
CM Finlayson ◽  
TP Farrell ◽  
DJ Griffiths

The stratification characteristics of Lake Moondarra (24�34'S.,139�35'E.), a man-made lake in north- western Queensland, have been studied. Evidence is presented that the lake approximates the warm polymictic type in which no persistent thermal stratification ever develops. During the cooler months, thermal stratification breaks down during the night; in the warmer months, the intense rainstorms prevent the establishment of a persistently stratified water column. The shallowness of the lake relative to its surface areaand the prevailing environmental conditions ensure that extensive periods of oxygen depletion do not develop in the water column. It is concluded that a strong and prolonged period of thermal stratification, with subsequent serious effects of the availability of dissolved oxygen in the deeper layers, would only arise if, in a particular year. there were no significant rainstorms.


Author(s):  
Mario Enrique Rueda ◽  
José Ernesto Mancera P.

With the purpose of assessing the impact generated by the use of an artisanal fishing method populary called "boliche", in the tropical coastal lagoon Ciénaga Grande de Santa Marta, different aspects were quantified; being one of them designed to analyze some physical-chemical alterations of the water column, produced during the fishing operations. The dissolved oxygen concentration, water transparency and seston composition and concentration, before and after of 70 boliche's thrusts were determinated. The results showthat fishing operations generate some momentary changes of little repercution to the ecosystem, such as particle resuspention principally inorganic an increase in seston concentration and a consequen water column transparency decrease. The dissolved oxygen concentration does not show appreciable alteration.


<em>Abstract</em>.—Historically, striped bass <em>Morone saxatilis</em> summer kills have been attributed to two mechanisms: stressors associated with crowding when striped bass are confined in isolated, cool refuges; and thermal stress or energetic deficit when hypolimnetic hypoxia (dissolved oxygen less than 2 mg/L) forces them into high-temperature surface waters. Here, we present observations suggesting that a third mechanism may account for some of these striped bass mortality events. During summer stratification, many relatively deep southeastern reservoirs develop hypoxia in the metalimnion, as well as near the bottom, isolating a layer of oxygenated hypolimnetic water between them. As these hypoxic zones expand in thickness and severity of oxygen depletion, the oxygenated layer between them shrinks both horizontally and vertically, and its oxygen content declines. Evidence suggests that striped bass summer kills can occur when fish are trapped in this isolated layer and its oxygen concentration declines below 2 mg/L or disappears altogether. The presence of coolwater forage fish such as alewife <em>Alosa pseudoharengus </em>or blueback herring <em>A. aestivalis </em>may increase the risk of striped bass kills by attracting them into the hypolimnetic oxygenated layer where they may become trapped. We draw upon examples from two southeastern reservoirs to illustrate this phenomenon, and discuss its implications for reservoir fisheries management, as well as possible approaches to minimize or avoid impacts.


2021 ◽  
Vol 7 ◽  
Author(s):  
Jun Zhou ◽  
Zhuo-Yi Zhu ◽  
Huan-Ting Hu ◽  
Gui-Ling Zhang ◽  
Qian-Qian Wang

The Changjiang Estuary and its adjacent East China Sea are among the largest coastal hypoxic sites in the world. The oxygen depletion in the near-bottom waters (e.g., meters above the seabed) off the Changjiang Estuary is caused by water column respiration (WCR) and sedimentary oxygen respiration (SOR). It is essential to quantify the contributions of WCR and SOR to total apparent oxygen utilization (AOU) to understand the occurrence of hypoxia off the Changjiang Estuary. In this work, we analyzed the δ18O and O2/Ar values of marine dissolved gas samples collected during a field investigation in July 2018. We observed that the δ18O values of dissolved oxygen in near-bottom waters ranged from 1.039 to 8.457‰ (vs. air), generally higher than those of surface waters (−5.366 to 2.336‰). For all the sub-pycnocline samples, the δ18O values were negatively related to O2 concentrations (r2 = 0.97), indicating apparent fractionation of δ18O during oxygen depletion in the water column. Based on two independent isotope fractionation models that quantified the isotopic distillation of dissolved oxygen concentration and its δ18O, the mean contributions of WCR and SOR to total near-bottom AOU were calculated as 53 and 47%, respectively. Beneath the pycnocline, the WCR contribution to the total AOU varied from 24 to 69%, and the SOR contribution varied from 31 to 76%. The pooled samples beneath both the pycnocline and upper mixed layer indicated that WCR contributions (%) to total AOU increased with increasing AOU (μmol/L), whereas SOR% – AOU had the reverse trend. We propose that the WCR% and SOR% contributions to the total AOU of the sub-pycnocline waters are dynamic, not stationary, with changes in ambient environmental factors. Under hypoxic conditions, we observed that up to 70% of the total AOU was contributed by WCR, indicating that WCR is the major oxygen consumption mechanism under hypoxia; that is, WCR plays a vital role in driving the dissolved oxygen to become hypoxic off the Changjiang Estuary.


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 324 ◽  
Author(s):  
Ximena Flores Melo ◽  
Jacobo Martín ◽  
Lounes Kerdel ◽  
François Bourrin ◽  
Cristina Beatriz Colloca ◽  
...  

This study examines the distribution and seasonal evolution of hydrographic, hydrodynamic, and nepheloid layers in Ushuaia Bay and the submerged glacial valley that connects it to the Beagle Channel. The hydrographic structure is highly seasonal, with a total mixing of the water column in winter and the appearance of a pycnocline between 50 and 70 m deep from spring to late autumn, mainly due to desalination. A counter-clockwise current sweeps the entire bay regardless of the season or phase of the tide. This current is at its maximum in the surface layer, allowing the rapid renewal of the bay’s waters, while deep currents are weak and imply a slow renewal of the valley’s waters. Turbid and oxygen-depleted structures are observed in summer in the valley. The combination of seasonal stratification, high organic matter inputs from planktonic production, oxygen consumption for remineralization, and sluggish circulation results in a decrease in near-bottom oxygen concentration in the glacial valley at the end of the stratified season, before mixing and re-oxygenation of the water column during the southern winter. The possible impact of dissolved oxygen depletion in the bottom waters of the valley on benthic organisms, like crustaceans, is discussed.


1965 ◽  
Vol 22 (3) ◽  
pp. 823-840 ◽  
Author(s):  
R. A. McHardy ◽  
B. McK. Bary

Diurnal and seasonal changes in the distributions of two planktonic ostracods, Conchoecia elegans Sars and C. alata minor McHardy, have been considered in relation to changes in the temperature, salinity, oxygen concentration, and subsurface light in Indian Arm, British Columbia. Both species occurred frequently throughout the water column except near the surface. There is the suggestion (reinforced by data from other B.C. inlets) of an upper temperature limit for C. alata minor, which is lower than for C. elegans. Salinity and dissolved oxygen environments appear to have been similar for the two species. An upinlet displacement of both species-populations which took place in the early months of the year could possibly have been initiated by water which had intruded into the depths of Indian Arm. The vertical distributions of the two species showed statistically significant changes which varied with time of day, season, and geographic position. It was not possible to show that the depth of daylight distribution was strongly related to the penetration of light.


1979 ◽  
Vol 14 (1) ◽  
pp. 71-88
Author(s):  
S.E. Penttinen ◽  
P.H. Bouthillier ◽  
S.E. Hrudey

Abstract Studies on the chronic low dissolved oxygen problems encountered under winter ice in the Red Deer River have generally been unable to account for dissolved oxygen depletion in terms of known manmade inputs. An experimental program was developed to assess the possible nature and approximate bounds of oxygen demand due to natural organic runoff carried to the Red Deer River by a small tributary stream, the Blindman River. The study employed an electrolytic respirometer on stream water samples subjected to prior concentration by vacuum evaporation. Evaluation of carbon and nitrogen budgets in conjunction with the measured oxygen demand indicate that biochemical oxygen demand is originating with natural organic runoff in tributaries of the Red Deer River. The results provide a basis for estimation of the possible contribution to the observed oxygen demand in the Red Deer River originating from natural organic runoff.


1992 ◽  
Vol 26 (7-8) ◽  
pp. 1769-1778 ◽  
Author(s):  
S.-I. Lee ◽  
B. Koopman ◽  
E. P. Lincoln

Combined chemical flocculation and autoflotation were examined using pilot scale process with chitosan and alum as flocculants. Positive correlation was observed between dissolved oxygen concentration and rise rate. Rise rate depended entirely on the autoflotation parameters: mixing intensity, retention time, and flocculant contact time. Also, rise rate was influenced by the type of flocculant used. The maximum rise rate with alum was observed to be 70 m/h, whereas that with chitosan was approximately 420 m/h. The efficiency of the flocculation-autoflotation process was superior to that of the flocculation-sedimentation process.


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