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The buffering capacity towards free sulphide in sediments of a coastal lagoon (Bassin d'Arcachon, France) - the relative importance of chemical and biological processes

Heijs, S.K. and Jonkers, H.M. and van Gemerden, H. and Schaub, B. and Stal, L.J. (1999) The buffering capacity towards free sulphide in sediments of a coastal lagoon (Bassin d'Arcachon, France) - the relative importance of chemical and biological processes. Estuarine Coastal and Shelf Science, 49, 21-35. ISSN 0272-7714.

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Official URL: http://dx.doi.org/10.1006/ecss.1999.0482

Abstract

The Bassin d'Arcachon (south-west France) was chosen as a model ecosystem to study the chemical and microbiological buffering towards free sulphide. Data were collected on the vertical distribution of oxygen, sulphur and iron compounds and the vertical distribution of colourless sulphur bacteria and sulphide-producing bacteria. In addition, data on the chemical and biological buffering capacity towards free sulphide were collected in sediment slurries from defined depth layers using a biological sulphide and oxygen monitor (BOSM) equipped with electrodes for oxygen, sulphide, redox and pH. The data showed that a substantial population of aerobic sulphide-oxidizing bacteria was present, yet buffering towards free sulphide could mainly be attributed to chemical processes: in particular, reactions with iron were of importance. Interestingly, the potential microbiological rate of sulphide oxidation was orders of magnitude higher than the rate of sulphate reduction reported for this ecosystem. The ecological implications of these observations for the Bassin d'Arcachon are that the powerful biological buffering capacity towards the free sulphide present will become effective after the chemical buffering capacity has been depleted. Under such conditions the colourless sulphur bacteria will no longer face the competition with iron, and thus may be expected to proliferate. The crucial factor then becomes the availability of oxygen. [KEYWORDS: sulphide; iron; sulphur/sulphide oxidizing bacteria sulphate-reducing bacteria; buffering capacity; coastal lagoon; sediment; France coast Sulfate-reducing bacteria; marine microbial mat; sulfide oxidation; sulfur bacteria; oxygen limitation; salt-marsh; iron; pyrite; reduction; seawater]

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:10737
Deposited On:25 Nov 2011 01:00
Last Modified:31 Mar 2014 10:56

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