Dynamics and trophic roles of heterotrophic protists in the plankton of a freshwater tidal estuary
Muylaert, K.; Van Mieghem, R.; Sabbe, K.; Tackx, M.; Vyverman, W. (1999). Dynamics and trophic roles of heterotrophic protists in the plankton of a freshwater tidal estuary, in: Muylaert, K. Distribution and dynamics of protist communities in a freshwater tidal estuary = Verspreiding en dynamiek van protistengemeenschappen in een zoetwatergetijdengebied. pp. 71-86 In: Muylaert, K. (1999). Distribution and dynamics of protist communities in a freshwater tidal estuary = Verspreiding en dynamiek van protistengemeenschappen in een zoetwatergetijdengebied. PhD Thesis. Universiteit Gent (RUG): Gent. 192 pp., more Related to:Muylaert, K.; Van Mieghem, R.; Sabbe, K.; Tackx, M.; Vyverman, W. (2000). Dynamics and trophic roles of heterotrophic protists in the plankton of a freshwater tidal estuary. Hydrobiologia 432(1-3): 25-36. https://dx.doi.org/10.1023/A:1004017018702, more |
| Keywords | Aquatic organisms > Heterotrophic organisms
Physics > Mechanics > Dynamics
Trophic relationships
Water bodies > Coastal waters > Coastal landforms > Coastal inlets > Estuaries
Bacteria [WoRMS]; Ciliophora [WoRMS]; Rotifera [WoRMS]
ANE, Belgium [Marine Regions]
Fresh water | | Author keywords | heterotrophic nanoflagellates; ciliates; rotifers; bacteria; microbial food web; tidal river; estuary; Schelde |
| Abstract | Freshwater tidal estuaries comprise the most upstream reaches of estuaries and are often characterised by the presence of dense bacterial and algal populations which provide a large food source for bacterivorous and algivorous protists. In 1996, the protistan community in the freshwater tidal reaches of the Schelde estuary was monitored to evaluate whether these high food levels are reflected in a similarly high heterotrophic protistan biomass. Protistan distribution patterns were compared to those of metazoan zooplankton to evaluate the possible role of top-down regulation of protists by metazoans. Apart from the algivorous sarcodine Asterocaelum, which reached high densities in summer, heterotrophic protistan biomass was dominated by ciliates and, second in importance, heterotrophic nanoflagellates (HNAN). HNAN abundance was low (annual average 2490 cells ml–1) and did not display large seasonal variation. It is hypothesised that HNAN were top-down controlled by oligotrich ciliates throughout the year and by rotifers in summer. Ciliate abundance was generally relatively high (annual average 65 cells ml–1) and peaked in winter (maximum 450 cells ml–1). The decline of ciliate populations in summer was ascribed to grazing by rotifers, which developed dense populations in that season. In winter, ciliate populations were probably regulated `internally' by carnivorous ciliates (haptorids and Suctoria). Our observations suggest that, in this type of productive ecosystems, the microbial food web is mainly top-down controlled rather than regulated by food availability. |
| Dataset | - Laboratory of Protistology and Aquatic Ecology (PAE). Ugent; De Vlaamse Waterweg NV: Belgium; (2020): OMES: Monitoring phytoplankton in the Zeeschelde., more
|
|
