|Influence of the organic pollution on bacterial, macrobenthic and meiobenthic populations in intertidal flats of the Dollard|
van Es, F.B.; van Arkel, M.A.; Bouwman, L.A.; Schröder, H.G.J. (1980). Influence of the organic pollution on bacterial, macrobenthic and meiobenthic populations in intertidal flats of the Dollard. Neth. J. Sea Res. 14(3-4): 288-304
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
|Authors|| || Top |
- van Es, F.B.
- van Arkel, M.A., more
- Bouwman, L.A.
- Schröder, H.G.J.
Large amounts of organic waste-water are discharged into the Ems-Dollard estuary, mainly in autumn and early winter. In November 1974 and June 1975 a number of samples were taken from the sediment of the tidal flats and analysed for bacterial numbers, organic carbon and mud content. Cores were taken to quantify macro- and meiofauna. Oxygen saturation was measured in the water column over the sediment. In November the oxygen saturation was less than 20% in a considerable part of the Dollard. It is not clear to what extent the inward increase in organic matter content of the sediment was influenced by the waste-water discharges. The correlation between the viable counts of aerobic heterotrophic bacteria and the organic matter content, as observed in the other parts of the estuary, was absent in the most polluted part of the Dollard. However, the differences between the numbers counted in November and June were not significant in that area. Numbers of sulphate-reducing bacteria decreéased sharply between November and June, indicating a dependency on the waste-water discharges. Numbers of sulphide-oxidizing bacteria decreased in summer concomitantly with the sulphate-reducing bacteria. These data suggest that, in contrast to the other parts of the estuary, in the Dollard obligate autotrophs play a predominant part in the populations of sulphide-oxidizing bacteria during the time of high waste discharges. Population diversities of meio-and macrofauna of the tidal flats were strongly decreased in the vicinity of the outfall. Total biomass of macrofauna decreased to zero, whereas meiofauna biomass significantly increased. Some possible explanations for the effects on the benthic fauna are given.