The jumbo squid, Dosidicus gigas (Ommastrephidae), living in oxygen minimum zones I: Oxygen consumption rates and critical oxygen partial pressures

2013 ◽  
Vol 95 ◽  
pp. 218-224 ◽  
Author(s):  
Lloyd A. Trueblood ◽  
Brad A. Seibel
Keyword(s):  
Oxygen Consumption ◽  
Dosidicus Gigas ◽  
Oxygen Minimum Zones ◽  
Jumbo Squid ◽  
Partial Pressures ◽  
Critical Oxygen ◽  
Consumption Rates ◽  
Oxygen Minimum

scholarly journals Substantial oxygen consumption by aerobic nitrite oxidation in oceanic oxygen minimum zones

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
J. M. Beman ◽  
S. M. Vargas ◽  
J. M. Wilson ◽  
E. Perez-Coronel ◽  
J. S. Karolewski ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Nitrate Reduction ◽  
Oxygen Affinity ◽  
Nitrite Oxidation ◽  
Oxygen Minimum Zones ◽  
Oxidation Rates ◽  
Consumption Rates ◽  
High Oxygen Affinity ◽  
Omic Data ◽  
Oxygen Minimum

AbstractOceanic oxygen minimum zones (OMZs) are globally significant sites of biogeochemical cycling where microorganisms deplete dissolved oxygen (DO) to concentrations <20 µM. Amid intense competition for DO in these metabolically challenging environments, aerobic nitrite oxidation may consume significant amounts of DO and help maintain low DO concentrations, but this remains unquantified. Using parallel measurements of oxygen consumption rates and 15N-nitrite oxidation rates applied to both water column profiles and oxygen manipulation experiments, we show that the contribution of nitrite oxidation to overall DO consumption systematically increases as DO declines below 2 µM. Nitrite oxidation can account for all DO consumption only under DO concentrations <393 nM found in and below the secondary chlorophyll maximum. These patterns are consistent across sampling stations and experiments, reflecting coupling between nitrate reduction and nitrite-oxidizing Nitrospina with high oxygen affinity (based on isotopic and omic data). Collectively our results demonstrate that nitrite oxidation plays a pivotal role in the maintenance and biogeochemical dynamics of OMZs.

scholarly journals The metabolic response of pteropods to acidification reflects natural CO<sub>2</sub>-exposure in oxygen minimum zones

2012 ◽  
Vol 9 (2) ◽  
pp. 747-757 ◽  
Author(s):  
A. E. Maas ◽  
K. F. Wishner ◽  
B. A. Seibel
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Ocean Acidification ◽  
Metabolic Response ◽  
Ammonia Excretion ◽  
Individual Species ◽  
Tropical Regions ◽  
Oxygen Minimum Zones ◽  
The Pacific ◽  
Oxygen Minimum

Abstract. Shelled pteropods (Thecosomata) are a group of holoplanktonic mollusks that are believed to be especially sensitive to ocean acidification because their aragonitic shells are highly soluble. Despite this concern, there is very little known about the physiological response of these animals to conditions of elevated carbon dioxide. This study examines the oxygen consumption and ammonia excretion of five pteropod species, collected from tropical regions of the Pacific Ocean, to elevated levels of carbon dioxide (0.10%, 1000 ppm). Our results show that pteropods that naturally migrate into oxygen minimum zones, such as Hyalocylis striata, Clio pyramidata, Cavolinia longirostris and Creseis virgula, were not affected by carbon dioxide at the levels and duration tested. Diacria quadridentata, which does not migrate, responds to high carbon dioxide conditions with reduced oxygen consumption and ammonia excretion. This indicates that the natural chemical environment of individual species may influence their resilience to ocean acidification.

scholarly journals Konsumsi Oksigen Ikan Uceng Nemacheilus fasciatus (Valenciennes, 1846) pada Kondisi Padat Tebar yang Berbeda

2019 ◽  
Vol 4 (2) ◽  
pp. 79
Author(s):  
Aliati Iswantari ◽  
Kurniawan Kurniawan ◽  
Bambang Priadi ◽  
Vitas Atmadi Prakoso ◽  
Anang Hari Kristanto
Keyword(s):  
Oxygen Consumption ◽  
Stocking Density ◽  
Ventilation Rate ◽  
Fish Growth ◽  
Oxygen Level ◽  
Hypoxic Conditions ◽  
Freshwater Aquaculture ◽  
Aquaculture System ◽  
Critical Oxygen ◽  
Consumption Rates

<strong>Oxygen Consumption of Barred Loach Nemacheilus fasciatus (Valenciennes, 1846) under Different Stocking Densities</strong>. In aquaculture system, fish growth is affected by stocking densities. One way to predict the effect of stocking density on growth is to determine fish metabolic rate through oxygen consumption measurements. In Barred loach Nemacheilus fasciatus (Valenciennes, 1846), the information was scarce on oxygen consumption. This study was to analyze the effect of stocking density on oxygen consumption in Barred loach conducted at Research Institute for Freshwater Aquaculture and Fisheries Extension, Bogor in May 2018. Barred loach (total length: 5.79 ± 0.47 cm, weight: 1.32 ± 0.34 g) was observed its oxygen consumption on three different stocking densities (5, 10, and 15 fish/L) by using closed respirometers (volume: 1.4 L) with three replications of each treatment. Measurement of oxygen consumption was carried out under normoxia and hypoxia conditions. In addition, fish behavior and ventilation rate were also observed and recorded according to treatment. The results showed that the highest oxygen consumption of barred loach was found in the stocking density of 5 fish/L (1250.6 ± 128.4 mg O2/kg/h) which was significantly different from the stocking density of 10 fish/L (626.9 ± 46.7 mg O2/kg/h) and 15 fish/L (596.9 ± 48.9 mg O2/kg/h). Meanwhile, oxygen consumption of barred loach under hypoxic conditions decreased significantly compared to normoxic conditions, which was marked by a decrease in their swimming activities. Although the ventilation rate in hypoxic conditions has decreased, the value was not significantly different from those of normoxia condition. Results of this study provide information that an increase in stocking density and hypoxic conditions in barred loach caused a decrease in oxygen consumption rates. In addition, this study showed that the critical oxygen level for barred loach was around 3.1 mg/L

scholarly journals On the role of circulation and mixing in the ventilation of oxygen minimum zones with a focus on the eastern tropical North Atlantic

2014 ◽  
Vol 11 (8) ◽  
pp. 12069-12136 ◽  
Author(s):  
P. Brandt ◽  
D. Banyte ◽  
M. Dengler ◽  
S.-H. Didwischus ◽  
T. Fischer ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Oxygen Supply ◽  
Oxygen Minimum Zones ◽  
Oxygen Budget ◽  
Tropical North Atlantic ◽  
Oxygen Minimum ◽  
Oxygen Concentrations

Abstract. Ocean observations carried out in the framework of the Collaborative Research Center 754 (SFB 754) "Climate-Biogeochemistry Interactions in the Tropical Ocean" are used to study (1) the structure of tropical oxygen minimum zones (OMZs), (2) the processes that contribute to the oxygen budget, and (3) long-term changes in the oxygen distribution. The OMZ of the eastern tropical North Atlantic (ETNA), located between the well-ventilated subtropical gyre and the equatorial oxygen maximum, is composed of a deep OMZ at about 400 m depth with its core region centred at about 20° W, 10° N and a shallow OMZ at about 100 m depth with lowest oxygen concentrations in proximity to the coastal upwelling region off Mauritania and Senegal. The oxygen budget of the deep OMZ is given by oxygen consumption mainly balanced by the oxygen supply due to meridional eddy fluxes (about 60%) and vertical mixing (about 20%, locally up to 30%). Advection by zonal jets is crucial for the establishment of the equatorial oxygen maximum. In the latitude range of the deep OMZ, it dominates the oxygen supply in the upper 300 to 400 m and generates the intermediate oxygen maximum between deep and shallow OMZs. Water mass ages from transient tracers indicate substantially older water masses in the core of the deep OMZ (about 120–180 years) compared to regions north and south of it. The deoxygenation of the ETNA OMZ during recent decades suggests a substantial imbalance in the oxygen budget: about 10% of the oxygen consumption during that period was not balanced by ventilation. Long-term oxygen observations show variability on interannual, decadal and multidecadal time scales that can partly be attributed to circulation changes. In comparison to the ETNA OMZ the eastern tropical South Pacific OMZ shows a similar structure including an equatorial oxygen maximum driven by zonal advection, but overall much lower oxygen concentrations approaching zero in extended regions. As the shape of the OMZs is set by ocean circulation, the widespread misrepresentation of the intermediate circulation in ocean circulation models substantially contributes to their oxygen bias, which might have significant impacts on predictions of future oxygen levels.

scholarly journals Life at stable low oxygen levels: adaptations of animals to oceanic oxygen minimum layers.

1998 ◽  
Vol 201 (8) ◽  
pp. 1223-1232 ◽  
Author(s):  
J J Childress ◽  
B A Seibel
Keyword(s):  
Water Column ◽  
Aerobic Metabolism ◽  
Oxygen Level ◽  
Low Oxygen ◽  
Oxygen Levels ◽  
Surface Areas ◽  
Partial Pressures ◽  
Stable Conditions ◽  
Consumption Rates ◽  
Oxygen Minimum

Zones of minimum oxygen level are found at intermediate depths in most of the world's oceans and, although the oxygen partial pressure in some of these 'oxygen minimum layers' is only a fraction of a kilopascal, populations of pelagic metazoans exist there. These oxygen minimum layers are areas of the water column and the associated benthos with stable conditions of continuously low oxygen level and low temperature at intermediate depths (400-1000 m depth) over vast areas. Off California, where PO2 at the oxygen minimum is 0.8 kPa, there are abundant populations of animals both in the water column and on the bottom. Farther to the south in the eastern tropical Pacific, oxygen partial pressures of less than approximately 0.4 kPa result in very low biomasses and diversity of animals at minimum layer depths. At the minimum oxygen levels found off California, most animals which inhabit the minimum zones appear to support their routine metabolic demands via aerobic metabolism. They do this by being very effective at removing oxygen from water. Among the adaptations of pelagic crustaceans to these conditions are: (1) enhanced ventilatory abilities, (2) enhanced percentage removal of O2 from the ventilatory stream, (3) large gill surface areas, (4) short diffusion distances from the water to the blood, and (5) hemocyanin respiratory proteins with a very high affinity for O2, high cooperativity and large Bohr effects. The lower O2 consumption rates of many deeper-living species are also functionally adaptive in that they facilitate aerobic survival at low PO2. However, they are not adaptations to the minimum layer, since similarly low rates are found in the same and comparable species living at the same depths in regions without well-developed minima, and these animals are unable to survive at the low PO2 values of the minima. While anaerobic metabolism may be important for metabolic rates above the routine level for most animals in the minimum layer, there is little evidence for the use of sustained anaerobiosis in the species studied. In summary, given the stable presence of very low O2 levels in the minima, the primary adaptations of animals living within them are those that support aerobic metabolism by giving the animals remarkable abilities to extract O2 from water. These abilities are notably better than those of animals adapted to unstable hypoxic environments, such as intertidal mudflats, while the latter animals rely to a much greater extent on anaerobiosis and perhaps on metabolic suppression to survive periods of anoxia.

scholarly journals On the role of circulation and mixing in the ventilation of oxygen minimum zones with a focus on the eastern tropical North Atlantic

2015 ◽  
Vol 12 (2) ◽  
pp. 489-512 ◽  
Author(s):  
P. Brandt ◽  
H. W. Bange ◽  
D. Banyte ◽  
M. Dengler ◽  
S.-H. Didwischus ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Oxygen Supply ◽  
Oxygen Minimum Zones ◽  
Oxygen Budget ◽  
Tropical North Atlantic ◽  
Oxygen Minimum ◽  
Oxygen Concentrations

Abstract. Ocean observations are analysed in the framework of Collaborative Research Center 754 (SFB 754) "Climate-Biogeochemistry Interactions in the Tropical Ocean" to study (1) the structure of tropical oxygen minimum zones (OMZs), (2) the processes that contribute to the oxygen budget, and (3) long-term changes in the oxygen distribution. The OMZ of the eastern tropical North Atlantic (ETNA), located between the well-ventilated subtropical gyre and the equatorial oxygen maximum, is composed of a deep OMZ at about 400 m in depth with its core region centred at about 20° W, 10° N and a shallow OMZ at about 100 m in depth, with the lowest oxygen concentrations in proximity to the coastal upwelling region off Mauritania and Senegal. The oxygen budget of the deep OMZ is given by oxygen consumption mainly balanced by the oxygen supply due to meridional eddy fluxes (about 60%) and vertical mixing (about 20%, locally up to 30%). Advection by zonal jets is crucial for the establishment of the equatorial oxygen maximum. In the latitude range of the deep OMZ, it dominates the oxygen supply in the upper 300 to 400 m and generates the intermediate oxygen maximum between deep and shallow OMZs. Water mass ages from transient tracers indicate substantially older water masses in the core of the deep OMZ (about 120–180 years) compared to regions north and south of it. The deoxygenation of the ETNA OMZ during recent decades suggests a substantial imbalance in the oxygen budget: about 10% of the oxygen consumption during that period was not balanced by ventilation. Long-term oxygen observations show variability on interannual, decadal and multidecadal timescales that can partly be attributed to circulation changes. In comparison to the ETNA OMZ, the eastern tropical South Pacific OMZ shows a similar structure, including an equatorial oxygen maximum driven by zonal advection but overall much lower oxygen concentrations approaching zero in extended regions. As the shape of the OMZs is set by ocean circulation, the widespread misrepresentation of the intermediate circulation in ocean circulation models substantially contributes to their oxygen bias, which might have significant impacts on predictions of future oxygen levels.

scholarly journals The metabolic response of pteropods to ocean acidification reflects natural CO<sub>2</sub>-exposure in oxygen minimum zones

2011 ◽  
Vol 8 (5) ◽  
pp. 10295-10316 ◽  
Author(s):  
A. E. Maas ◽  
K. F. Wishner ◽  
B. A. Seibel
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Ocean Acidification ◽  
Metabolic Response ◽  
Ammonia Excretion ◽  
Individual Species ◽  
Tropical Regions ◽  
Oxygen Minimum Zones ◽  
The Pacific ◽  
Oxygen Minimum

Abstract. Shelled pteropods (Thecosomata) are a group of holoplanktonic mollusks that are believed to be especially sensitive to ocean acidification because their aragonitic shells are highly soluble. Despite this concern, there is very little known about the physiological response of these animals to conditions of elevated carbon dioxide. This study examines the oxygen consumption and ammonia excretion of five pteropod species, collected from tropical regions of the Pacific Ocean, to elevated levels of carbon dioxide (0.10%, 1000 ppm). Our results show that pteropods that naturally migrate into oxygen minimum zones, such as Hyalocylis striata, Clio pyramidata, Cavolinia longirostris and Creseis virgula, were not affected by carbon dioxide at the levels and duration tested. Diacria quadridentata, which does not migrate, responds to high carbon dioxide conditions with reduced oxygen consumption and ammonia excretion. This indicates that the natural chemical environment of individual species influences their resilience to ocean acidification.

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