Study of the distribution of mercury in the various compartments of the North-Sea and Scheldt estuary ecosystems
Baeyens, W.F.J.; Decadt, B.; Elskens, I. (1979). Study of the distribution of mercury in the various compartments of the North-Sea and Scheldt estuary ecosystems. Oceanol. Acta 2(4): 447-457
In: Oceanologica Acta. Elsevier/Gauthier-Villars: Montreuil. ISSN 0399-1784; e-ISSN 1878-4143, more
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| Keywords |
Marine/Coastal; Brackish water |
| Authors | | Top |
- Baeyens, W.F.J., more
- Decadt, B.
- Elskens, I.
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| Abstract |
The distribution of mercury in various compartments of the North Sea and Scheldt ecosystems was investigated. The experimental results showed that: (1), in the North Sea, the ratio of particulate to dissolved mercury in the water column was close to 1 : 1, while in the estuary (particularly in its upper portion) this ratio was much higher; (2), the mercury content of living organisms was higher in phyto- and zooplankton than in fish, although detrital matter still contained about five times more mercury than phytoplankton; and (3), the concentration of mercury in marine sediments was situated between those found in zooplankton and fish. Thermodynamic stability diagrams for aqueous and solid mercury compounds in seawater and brackish water provided valuable information for the interpretation of the observed mercury distribution. Under reducing conditions, mercury-sulphide compounds were predominant, in both water systems. These compounds play a very important role in the accumulation and release of mercury in sediments (the stable solid compound under reducing conditions, cinnabar, determines the mobility of mercury in the interstitial water), and in living organisms (the latter produce metallothioneins, which contain a large number of - SH groups and show high affinities for mercury). In combination with electrostatic forces these compounds probably also play a role in the process of adsorption of Hg CI;, which is theoretically the predominant mercury compound in the North Sea and the major part of the Scheldt estuary, on suspended matter. |
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