SENSITIVITY OF OXYGEN MINIMUM ZONES DUE TO CARBON DIOXIDE RADIATIVE FORCINGS

2018 ◽  
Author(s):  
Kristina Wolfe ◽  
◽  
Arne M.E. Winguth ◽  
Kelin Zhuang ◽  
Taylor M. Hughlett
Keyword(s):  
Carbon Dioxide ◽  
Radiative Forcings ◽  
Oxygen Minimum Zones ◽  
Oxygen Minimum

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 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.

CARBONATE SYSTEM TRANSFORMATION IN THE SEVASTOPOL BAY (THE BLACK SEA)

2017 ◽  
Author(s):  
Natalia Orekhova ◽  
Natalia Orekhova ◽  
Eugene Medvedev ◽  
Eugene Medvedev ◽  
Sergey Konovalov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Cycle ◽  
Black Sea ◽  
Total Alkalinity ◽  
The Black Sea ◽  
Natural State ◽  
Carbonate System ◽  
Oxygen Minimum Zones ◽  
Sevastopol Bay ◽  
Oxygen Minimum

A 20% increase of the carbon dioxide concentration in the atmosphere during the last century and a dramatic increase in nutrient load to marine systems due to human activity have resulted in pronounced carbon cycle transformation in coastal areas. Acidification and carbon dioxide increasing in the water column and appearance of oxygen minimum zones are reported for the worldwide coast. This makes ecological assessment of aquatic systems, including key cycles of elements, an important social and scientific task. In this study, we present information on the inorganic part of the carbon cycle and its transformation in the Sevastopol Bay (the Black Sea). This semi-enclosed coastal area has been under heavy anthropogenic pressure over the last century. Municipal and industrial sewage discharge, maritime activities, including excavation of bottom sediments, provide additional sources of nutrients and organic carbon. We present data on dynamics of the inorganic part of the carbon cycle from 1998 – 2015. Values of pH and total alkalinity were obtained analytically, whereas CO2, HCO3-, CO32- concentrations and pCO2 values were calculated. Dissolved inorganic carbon (DIC) and its partitioning into CO2, HCO3-, CO32- demonstrate the state of the carbon cycle and its evolution. Our observations reveal up to 2% increase of DIC from 1998 – 2015, but the value of pCO2 has increased by up to 20% in line with declining pH (acidification). Seasonal variations are far more pronounced and reveal extremes for areas of oxygen minimum zones. This results in negative consequences for the ecosystem, but these consequences for the Sevastopol Bay’s ecosystem remain reversible and the carbonate system can be restored to its natural state.

CARBONATE SYSTEM TRANSFORMATION IN THE SEVASTOPOL BAY (THE BLACK SEA)

2017 ◽  
Author(s):  
Natalia Orekhova ◽  
Natalia Orekhova ◽  
Eugene Medvedev ◽  
Eugene Medvedev ◽  
Sergey Konovalov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Cycle ◽  
Black Sea ◽  
Total Alkalinity ◽  
The Black Sea ◽  
Natural State ◽  
Carbonate System ◽  
Oxygen Minimum Zones ◽  
Sevastopol Bay ◽  
Oxygen Minimum

A 20% increase of the carbon dioxide concentration in the atmosphere during the last century and a dramatic increase in nutrient load to marine systems due to human activity have resulted in pronounced carbon cycle transformation in coastal areas. Acidification and carbon dioxide increasing in the water column and appearance of oxygen minimum zones are reported for the worldwide coast. This makes ecological assessment of aquatic systems, including key cycles of elements, an important social and scientific task. In this study, we present information on the inorganic part of the carbon cycle and its transformation in the Sevastopol Bay (the Black Sea). This semi-enclosed coastal area has been under heavy anthropogenic pressure over the last century. Municipal and industrial sewage discharge, maritime activities, including excavation of bottom sediments, provide additional sources of nutrients and organic carbon. We present data on dynamics of the inorganic part of the carbon cycle from 1998 – 2015. Values of pH and total alkalinity were obtained analytically, whereas CO2, HCO3-, CO32- concentrations and pCO2 values were calculated. Dissolved inorganic carbon (DIC) and its partitioning into CO2, HCO3-, CO32- demonstrate the state of the carbon cycle and its evolution. Our observations reveal up to 2% increase of DIC from 1998 – 2015, but the value of pCO2 has increased by up to 20% in line with declining pH (acidification). Seasonal variations are far more pronounced and reveal extremes for areas of oxygen minimum zones. This results in negative consequences for the ecosystem, but these consequences for the Sevastopol Bay’s ecosystem remain reversible and the carbonate system can be restored to its natural state.

scholarly journals In situ quantification of ultra‐low O 2 concentrations in oxygen minimum zones: Application of novel optodes

2016 ◽  
Vol 14 (12) ◽  
pp. 784-800 ◽  
Author(s):  
Morten Larsen ◽  
Philipp Lehner ◽  
Sergey M. Borisov ◽  
Ingo Klimant ◽  
Jan P. Fischer ◽  
...  
Keyword(s):  
Oxygen Minimum Zones ◽  
Oxygen Minimum

scholarly journals Expanded oxygen minimum zones during the late Paleocene-early Eocene: Hints from multiproxy comparison and ocean modeling

2016 ◽  
Vol 31 (12) ◽  
pp. 1532-1546 ◽  
Author(s):  
X. Zhou ◽  
E. Thomas ◽  
A. M. E. Winguth ◽  
A. Ridgwell ◽  
H. Scher ◽  
...  
Keyword(s):  
Ocean Modeling ◽  
Early Eocene ◽  
Oxygen Minimum Zones ◽  
Late Paleocene ◽  
Oxygen Minimum

scholarly journals Toward a global calibration for quantifying past oxygenation in oxygen minimum zones using benthic Foraminifera

2021 ◽  
Author(s):  
Martin Tetard ◽  
Laetitia Licari ◽  
Kazuyo Tachikawa ◽  
Ekaterina Ovsepyan ◽  
Luc Beaufort
Keyword(s):  
North Pacific ◽  
Transfer Functions ◽  
Late Quaternary ◽  
Global Climate ◽  
Single Species ◽  
Pore Waters ◽  
Oxygen Minimum Zones ◽  
Global Calibration ◽  
Circularity Index ◽  
Oxygen Minimum

Abstract. Oxygen Minimum Zones (OMZs) are oceanic areas largely depleted in dissolved oxygen, nowadays considered in expansion in the face of global warming. Their ecological and economic consequences are being debated. The investigation of past OMZ conditions allows us to better understand biological and physical mechanisms responsible for their variability with regards to climate change, carbon pump and carbonate system. To investigate the relationship between OMZ expansion and global climate changes during the late Quaternary, quantitative oxygen reconstructions are needed, but are still in their early development. Here, past bottom water oxygenation (BWO) was quantitatively assessed through a new, fast, semi-automated, and taxonfree morphometric analysis of benthic foraminiferal tests, developed and calibrated using Eastern North Pacific (ENP) and the Eastern South Pacific (ESP) OMZs samples. This new approach is based on an average size and circularity index for each sample. This method, as well as two already published micropalaeontological approaches based on benthic foraminiferal assemblages variability and porosity investigation of a single species, were here calibrated based on availability of new data from 23 core tops recovered along an oxygen gradient (from 0.03 to 1.79 mL.L−1) from the ENP, ESP, AS (Arabian Sea) and WNP (Western North Pacific, including its marginal seas) OMZs. Global calibrated transfer functions are thus herein proposed for each of these methods. These micropalaeontological reconstruction approaches were then applied on a paleorecord from the ENP OMZ to examine the consistency and limits of these methods, as well as the relative influence of bottom and pore waters on these micropalaeontological tools. Both the assemblages and morphometric approaches (that is also ultimately based on the ecological response of the complete assemblage and faunal succession according to BWO) gave similar and consistent past BWO reconstructions, while the porosity approach (based on a single species and its unique response to a mixed signal of bottom and pore waters) shown ambiguous estimations.

scholarly journals Modulation of the vertical particles transfer efficiency in the Oxygen Minimum Zone off Peru

2018 ◽  
Author(s):  
Marine Bretagnon ◽  
Aurélien Paulmier ◽  
Véronique Garçon ◽  
Boris Dewitte ◽  
Sérena Illig ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Sediment Traps ◽  
Biogeochemical Cycles ◽  
High Temporal Resolution ◽  
Oxygen Minimum Zones ◽  
Marine Life ◽  
Minimum Zone ◽  
Earth’S System ◽  
Oxygen Minimum

Abstract. The fate of the Organic Matter (OM) produced by marine life controls the major biogeochemical cycles of the Earth’s system. The OM produced through photosynthesis is either preserved, exported towards sediments or degraded through remineralisation in the water column. The productive Eastern Boundary Upwelling Systems (EBUSs) associated with Oxygen Minimum Zones (OMZs) should foster OM preservation due to low O2 conditions, but their intense and diverse microbial activity should enhance OM degradation. To investigate this contradiction, sediment traps were deployed near the oxycline and in the OMZ core on an instrumented moored line off Peru, providing high temporal resolution O2 series characterizing two seasonal steady states at the upper trap: suboxic ([O2] 

scholarly journals Anthropogenic carbon in the eastern South Pacific Ocean

2007 ◽  
Vol 4 (3) ◽  
pp. 1815-1837 ◽  
Author(s):  
L. Azouzi ◽  
R. Gonçalves Ito ◽  
F. Touratier ◽  
C. Goyet
Keyword(s):  
Pacific Ocean ◽  
General Trend ◽  
South Pacific ◽  
Hydrodynamic Characteristics ◽  
Eastern Pacific Ocean ◽  
Previous Knowledge ◽  
Oxygen Minimum Zones ◽  
South Pacific Ocean ◽  
Anthropogenic Carbon ◽  
Oxygen Minimum

Abstract. We present results from the BIOSOPE cruise in the eastern South Pacific Ocean. In particular, we present estimates of the anthropogenic carbon CantTrOCA distribution in this area using the TrOCA method recently developed by Touratier and Goyet (2004a, b) and Touratier et al. (2007). We study the distribution of this anthropogenic carbon taking into account of the hydrodynamic characteristics of this region. We then compare these results with earlier estimates in nearby areas of the anthropogenic carbon as well as other anthropogenic tracer (CFC-11). The highest concentrations of CantTrOCA are located around 13° S 132° W and 32° S 91° W, and their concentrations are larger than 80 μmol kg−1 and 70 μmol kg−1, respectively. The lowest concentrations were observed below 800 m depths (≤2 μ mol kg−1) and at the Oxygen Minimum Zones (OMZ), mainly around 140° W (<11 μmol kg−1). The comparison with earlier work in nearby areas provides a general trend and indicates that the results presented here are in general agreement with previous knowledge. This work further improves our understanding on the penetration of anthropogenic carbon in the eastern Pacific Ocean.

Sign in / Sign up

Export Citation Format

Share Document