|Temporele patronen in de samenstelling en gemeenschapsstructuur van de ichtyofauna in de Beneden-Zeeschelde. Een synthese van de biologische data in de Electrabel Kerncentrale te Doel tussen 1991 en 2010|
Wambacq, M. (2010). Temporele patronen in de samenstelling en gemeenschapsstructuur van de ichtyofauna in de Beneden-Zeeschelde. Een synthese van de biologische data in de Electrabel Kerncentrale te Doel tussen 1991 en 2010. MSc Thesis. Katholieke Universiteit Leuven (KUL), Faculteit der Wetenschappen, Departement Biologie: Leuven. 82 pp.
|Available in|| Author |
VLIZ: Non-open access 215701
|Document type: Dissertation|
Community composition; Fish; Temporal distribution; Belgium, Zeeschelde, Doel [Marine Regions]; Marine; Brackish water
The fish community of the upper Scheldt estuary (Belgium) was sampled by monitoring of fish in the cooling water of the Power Plant at Doel. Samplings were performed monthly during the period September 1991 to April 2010. Based on these data, the fish community was investigated for changes over the last 20 years. In a first step, the general characteristics of the diversity within the fish community were studied. Over the period of 20 years, 62 species were observed. The fish community has a maximum number of species in autumn and winter and the lowest species numbers in May and June. When comparing the number of species throughout the sampling period, it is clear that the sampling effort plays an important role. After standardization of the sampling effort, the number of observed species continues to increase. The current fish community has not reached a stable equilibrium, which may be attributed to an improved water quality. In a second step, we investigated whether changes have occurred in the fish community trough a multivariate analysis. Most species have a clear seasonal pattern. Filtering out this seasonal pattern, no clear temporal structure of the fish community can be seen. In a final step, we identify the environmental factors influencing the fish community through a multivariate analysis. Chlorophyll a and Oxygen are important factors for the fish community. Both variables give an indication of improvements in water quality in recent years. Explaining the observed densities based on generalized linear models where both environmental and time variables are included represents a challenge. From the statistical analysis of 20 years of fish data a tendency to interdecadal variation has been detected together with an indication for a change in the fish community due to the improved water quality.