The carbonate system in the Black Sea

Goyet, Catherine; Bradshaw, Alvin; Brewer, Peter G.

doi:10.1016/s0198-0149(10)80023-8

Cited by 72 publications

(33 citation statements)

References 14 publications

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“…As we did not collect dissolved nutrient samples at 4.5 m, we cannot say if there were similar distributions of NO3-, NH4+ and SRP. The rapid increase in alkalinity across the pycnocline of Lake KauhakG is consistent with the production of alkalinity in anoxic waters by organic matter oxidation through sulfate reduction, as reported for the Black Sea (Goyet et al 1991).…”

Section: Discussionsupporting

confidence: 88%

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Donachie¹,

Kinzie²,

Bidigare³

et al. 1999

Aquat. Microb. Ecol.

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We undertook the first combined microbiological and hydrochemical study of the 248 m deep meromichc Lake KauhakG. Situated at sea level 1.6 km from the sea in the crater of an extinct volcano on the island of Moloka'i, Hawai'i, USA, Lake KauhakB has the highest relative depth (ratio of depth to surface area, z, = 374 %) of any lake in the world. The upper 4.5 m were stratified (T= 23 to 26'C, salinity = 6 to 24.5), but below a pycnocline at -4.5 m temperature and salinity were uniform (T = -26.25"C; salinity = 32). Seawater hkely intrudes by horizontal hydraulic conductivity through rock separating the lake and the Pacific Ocean. Anoxia commenced below 2 m. Hydrogen sulfide was undetectable at 4 m. but averaged -130 PM between 5 and 28 m. Dissolved inorganic carbon concentrations ranged from -1.50 mM at the surface to -3.3 mM below 5 m. Total organic carbon peaked at 0.94 mM above the pycnocline hut rernaiced about 0.30 mM be!ow 5 m. Soluble reactive phosphorus and ammunium concentrations, nanomolar above the pycnocline, increased to -28 and l75 PM, respectively, at greater depth. Nitrate attained 3.7 PM in shallow water, but was -0.2 pM from the pycnocline to 100 m. Leucine aminopeptidase (LAPase) activity at the surface exceeded 1100 nmol of substrate hydrolyzed I-' h-' Activities of a-and P-glucosidase were lower, but showed depth distributions similar to that of LAPase. Surface waters hosted large and diverse picoplankton populations; chlorophyll a (chl a) exceeded 150 1-19 I-'. and heterotrophic bacteria and autofluorescent bacteria attained 2 X log and 9 X 109 1-l, respectively. Filamentous cyanobacteria and 'Proch1orococcus'-like autotrophs occurred only in the upper 2 m. Chl a was the dominant pigment above 2 m, but pigment diversity increased markedly in anoxic waters between 3 and 5 m. Lake Kauhako is a unique habitat for further studies, particularly of interactions among flora and fauna restricted to a shallow water column within a single basin.

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Section: Discussionsupporting

confidence: 88%

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Donachie¹,

Kinzie²,

Bidigare³

et al. 1999

Aquat. Microb. Ecol.

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“…However, this theoretical ''alkalinity pump'' (Kempe, 1990) can be efficient only if the reduced inorganic species produced are not further reoxidised, or if the reoxidation occurs in chemical pathways that do not release protons. This happens for example, when H 2 S escapes to the atmosphere (Yao and Millero, 1995), when iron sulphides are produced (Cook et al, 1986;Goyet et al, 1991;Yao and Millero, 1995), when sulphides are reoxidised by oxygen into elemental sulphur (Goyet et al, 1991) or when Fe ++ precipitate with phosphates (Anschutz et al, 1998). We have no data to provide evidence for such reactions in the Scheldt basin, except the fact that suspended particulate matter in this hypoxic zone is enriched in iron sulphides (Verlan et al, 1998).…”

Section: Gwenae¨l Abril and Michel Frankignoulle 846mentioning

confidence: 95%

“…Frankignoulle et al (1996) have observed a significant decrease of alkalinity with nitrification in the water column of the upper Scheldt estuary. Important alkalinity production due to ammonification, denitrification, Mn(IV)-, Fe(III)-or SO 4 -reductions have been reported in lakes (Cook et al, 1986), in an anoxic fjord (Yao and Millero, 1995) and in the Black sea (Goyet et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

Nitrogen–alkalinity interactions in the highly polluted scheldt basin (belgium)

Abril

Frankignoulle

2001

Water Research

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Abstract}We present results of one year observations in highly heterotrophic and oxygen-depleted rivers of the polluted Scheldt basin. Monthly measurements revealed a high variability for dissolved inorganic carbon and nitrogen, with the following strong parallelism: highest alkalinity and NH 4 + were associated with lowest NO 3 À and oxygen and vice-versa. In river water incubations, nitrification lowered the alkalinity whereas denitrification raised it; in an anoxic, NO 3 À -free incubation an increase of alkalinity was observed, partially due to ammonification. A stoichiometric analysis, taking into account the amount of protons produced or consumed by each process involving nitrogen, revealed that monthly variations of NO 3 À and NH 4 + with ammonification, nitrification and denitrification could explain the 28 and 62% alkalinity variations at all stations, except one. The remaining part of the alkalinity variations was attributed to other anaerobic processes (Mn-, Fe-and SO 4 -reductions). This trend seems to be the result of the whole catchment metabolism (riverine waters and sediments, sewage networks and agricultural soils). The observed HCO 3 À concentrations in the Scheldt basin were 2-10 times higher than the representative concentrations reported in pristine basins and used in chemical weathering models. This suggests the existence of an anthropogenic source, originating from organic matter decomposition. We conclude that in highly polluted basins, nitrogen transformations strongly influence the acid-base properties of water. #

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“…Just for this reason the values of total alkalinity, pH and total inorganic carbon are basic for subsequent calculating the state of the inorganic carbon cycle. At the same time, studying of the Black Sea water general alkalinity was not systematic; among the papers published in the 1980ies, one should note [6][7][8][9][10][11].…”

mentioning

confidence: 99%

“…It is more convenient to start examining the features of the TA spatial distribution in the Black Sea regions under study from its vertical profiles throughout the whole water thickness using the depth and the relative density scales. The data of 1988 (in the density scale) [7] are given in Fig. 2 for comparison.…”

mentioning

confidence: 99%

Total Alkalinity and pH in the Black Sea Waters in 2010-2011

Кондратьев¹,

Medvedev²,

Konovalov³

2017

PhO

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Based on the data of the expeditionary researches of Marine Hydrophysical Institute in 2010-2011, the total alkalinity TA and pH distributions in the Black Sea waters including the Danube estuary region and the changes in the TA vertical distribution since 1988 are analyzed. It is shown that the coastal and deep-sea water TA is strongly influenced by the river flow. In the Black Sea aerobic zone, TA does not change virtually with depth and does not depend on pH. In the anaerobic zone, it weakly depends on pH, but its dependence on the hydrogen sulfide concentration is of a linear character.Comparison with the data obtained in 1988 shows that in course of the last 20 years no noticeable changes in the TA values in the Black Sea aerobic and anaerobic zones took place, whereas on the sulfide zone upper boundary the total alkalinity increased by 0.04 mg-eq*l -1 .Keywords: total alkalinity, pH, aerobic and anaerobic waters, the Black Sea coastal and deep-sea areas. Introduction. In course of the whole period of hydrochemical studies in the World Ocean, a few tens of definitions of the term "seawater alkalinity" have been proposed [1]. It is explained by the fact that this parameter is a complex function of the contents of several components which are, in most cases, not conservative. In other words, relative abundance (in relation to the salinity value) of different components varies in a different manner. At the same time, importance of this parameter for assessing the marine environment state explains constant attention of the oceanographers studying both distribution and nature of this index. Moreover, in course of the last decade the parameter acquired a special significance due to its stupendous role in regulating the processes conditioning the СО2 flows on the atmosphere-ocean boundary and also the carbon cycle in the marine environment.According to [2], the seawater alkalinity is treated as the value characterizing predominance of the "base efficiency" over the "acid efficiency". Having been examined, balance of the charges shows that the sum of the weak acids (carbonic, boric, phosphoric, silicic etc.) anions in seawater basically equalizes excess of the conservative cations ([Na

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The carbonate system in the Black Sea

Cited by 72 publications

References 14 publications

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Lake Kauhako-, Moloka'i, Hawai'i: biological and chemical aspects of a morpho-ectogenic meromictic lake

Nitrogen–alkalinity interactions in the highly polluted scheldt basin (belgium)

Total Alkalinity and pH in the Black Sea Waters in 2010-2011

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