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

SK Heijs*, HM Jonkers, H van Gemerden, BEM Schaub, LJ Stal

*Corresponding author for this work

    Research output: Contribution to journalArticleAcademicpeer-review

    43 Citations (Scopus)

    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. (C) 1999 Academic Press.

    Original languageEnglish
    Pages (from-to)21-35
    Number of pages15
    JournalEstuarine coastal and shelf science
    Volume49
    Issue number1
    Publication statusPublished - Jul-1999

    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

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