Summertime in situ monitoring of oxygen depletion in Amursky Bay (Japan/East Sea)

Tishchenko, P. Ya.; Tishchenko, P. Ya.; Лобанов, В. Б.; Sergeev, A. F.; Semkin, P. Yu.; Zvalinsky, V. I.

doi:10.1016/j.csr.2016.02.014

Cited by 17 publications

(13 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Amursky Bay is a secondary bay of the PGB that regularly demonstrates hypoxic events in the bottom water in the late summer [16]. Available historical data clearly demonstrate that the lowest values of DO obtained in the summer in the bottom waters of Amursky Bay have been steadily decreasing over the last 80 years (Figure 2; [17]). The slope of the solid line in Figure 5b indicates summer acidifications of the bottom waters on the shelf of the JES caused by OM respiration, which varies from −0.0080 pH units/y (1932) to −0.0033 pH units/y (2014).…”

Section: Resultsmentioning

confidence: 99%

“…In 2007 and 2011, the DO saturation degree was 1.7 and 4.3, respectively. Additionally, it should be noted that under limited oxygen conditions (hypoxia), the rate of microbial oxidation of OM at the water/bottom sediment interface is low, because this reaction is of the first order [17].…”

Section: Resultsmentioning

confidence: 99%

“…Hydrochemical observations (DO, phosphorus, silica, pH, DIC, and ammonium) suggest that the main cause of hypoxia is the degradation of "excess" diatoms at the water/bottom sediment interface under slow water dynamic conditions. Available historical data clearly demonstrate that the lowest values of DO obtained in the summer at the bottom waters of Amursky Bay have been steadily decreasing over the last 80 years (Figure 2; [17]). The Peter the Great Bay (PGB), located on the northwestern shelf of the JES (Figure 1b), reveals seasonal hypoxia [15].…”

Section: Introductionmentioning

confidence: 96%

See 2 more Smart Citations

Acidification and Deoxygenation of the Northwestern Japan/East Sea

Tishchenko

Лобанов

Kaplunenko

et al. 2021

JMSE

Self Cite

View full text Add to dashboard Cite

Seasonal hypoxia in the bottom waters of the Peter the Great Bay (PGB) of the Japan/East Sea (JES) occurs in summer. Using the empirical relationship between dissolved oxygen (DO) and pH obtained for hypoxic conditions and available historical DO data, acidification rates were estimated. Carefully sampled time-series observations from the northwestern part of the JES, carried out from 1999 to 2014 along the 132°20′ E and 134°00′ E longitudes, were chosen to determine the interannual variability of the sea’s hydrochemical parameters (DO, pH, and TA—the total alkalinity phosphates, nitrate, and silicates). To limit the effects of seasonal and spatial variability, only data obtained in the warm period were used. Additionally, all data from depths shallower than 500 m were discarded because they are affected by high natural variability, mostly due to strong mesoscale dynamic structures. Our results demonstrated that the pH and DO concentrations measured in the Upper Japan Sea Proper Water (750 m), Lower Japan Sea Proper Water (1250, 1750, 2250 m), and Bottom Water (3000 m) have been decreasing in recent years. On the other hand, calculated normalized dissolved inorganic carbon (NDIC), CO2 partial pressure (pCO2), and measured nutrient concentrations have been increasing. Maximum rates of acidification and deoxygenation are occurring at around 750 m. The annual rate of increase of pCO2 in the water exceeds the atmospheric rate more than 2-fold at a depth of 750 m. The observed variability of the hydrochemical properties can be explained by the combination of the slowdown ventilation of the vertical water column and eutrophication. However, the results obtained here are valid for the subpolar region of the JES, not for the whole sea. The synchronization of the deoxygenation of the open part of the JES and PGB has been found.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

See 1 more Smart Citation

Acidification and Deoxygenation of the Northwestern Japan/East Sea

Tishchenko

Лобанов

Kaplunenko

et al. 2021

JMSE

Self Cite

View full text Add to dashboard Cite

show abstract

“…During autumn and winter, natural drivers (such as upwelling, decreased river runoff, and winter convection) alleviate hypoxia. At the same time, the available published historical data clearly demonstrate that the lowest values of DO obtained in the summer in the bottom waters of Amursky Bay have been systematically decreasing with time over the last 80 years, and there is a period between the 1960s and 1980s when Amursky Bay became hypoxic during the summer, most likely starting in the 1970s (Tishchenko et al, 2016). A direct biological consequence of hypoxia is the documented mortality of small fish (e.g.…”

Section: Peter the Great Baymentioning

confidence: 95%

Long‐term changes of marine subtidal benthic communities in North East Asia (Yellow and Japan seas) in a global change context: A review

Chen

Lutaenko

et al. 2020

Aquatic Conservation

View full text Add to dashboard Cite

show abstract

“…As a rule, the formation of such zones due to a combination of several anthropogenic factorsexcessive intake of biogenic compounds (eutrophication), increased water turbidity and, as a result, decreased water transparency, siltation of the bottom, and the development of phytoplankton [5]. In addition, the vertical stratification as a result of the formation of thermocline and/or halocline, weak water mixing, summer temperature increase, and others can serve as a cause of the formation of hypoxic zones [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

The new AqE gene studied in non-tetrapoda vertebrates is high conserved

Puzakova¹,

Пузаков

Gostyukhina

2020

Preprint

View full text Add to dashboard Cite

Background: The AqE gene encoding the NAD(P)H-dependent LDH2/MDH2 oxidoreductase has been described in living organisms predominantly in the aquatic environment. It was shown that the gene is present in bacteria and archaea. In the plant kingdom this gene is present only in algae. Animals have the AqE gene in all groups, from protozoa to fish. In the ancestor of tetrapods, the gene disappears and, accordingly, is absent in amphibians, reptiles, birds and mammals. It was suggested that the gene is involved in anaerobic respiration. The loss of the AqE gene in animals and plants is likely to be associated with living on land and the corresponding restructuring of their metabolic pathways, due to oxygen saturation and the absence of natural hypoxia as in aquatic organisms Results: A study of the distribution of the AqE gene among non-tetrapoda vertebrates showed that it is present in the genomes of bony and cartilaginous fishes, as well as in the genomes of hagfishes and lampreys. In addition, it was reliably shown that, for representatives of Cypriniformes, the AqE gene was lost, and for representatives of Salmoniformes, it underwent significant deletions, which most likely led to its pseudogenization. Conclusions: In most orders of non-tetrapoda vertebrates, the AqE gene remains highly conserved. This suggests that the AqE in aquatic vertebrates is an essential gene and undergoes to rigorous selection. AqE gene has the highest homology with the archaeal ComC that encoding SLDH. Based on the similarity of substrates, it cannot be excluded that the enzyme encoded by the AqE gene is involved in the malate-aspartate shuttle mechanism or biosynthesis of energy coenzyme M equivalent.

show abstract

Summertime in situ monitoring of oxygen depletion in Amursky Bay (Japan/East Sea)

Cited by 17 publications

References 27 publications

Acidification and Deoxygenation of the Northwestern Japan/East Sea

Acidification and Deoxygenation of the Northwestern Japan/East Sea

Long‐term changes of marine subtidal benthic communities in North East Asia (Yellow and Japan seas) in a global change context: A review

The new AqE gene studied in non-tetrapoda vertebrates is high conserved

Contact Info

Product

Resources

About