1. A Fish based index of biotic integrity for the Schelde estuary
Peter Goethals, Veronique Adriaenssens, Jan Breine, Ilse Simoens, Dirk Ercken, Joachim Maes, Chris Van Liefferinghe, Frans Ollevier,
Claude Belpaire & Niels De Pauw

2. P. Goethals et al. - 9 October 2002
IBI development
GOAL: develop a decision system that classifies fish community samples of river sites in five quality classes, eventually giving additional information on different quality aspects and the causes of the actual quality (tracing responsible impact(s) for the actual quality)
P. Goethals et al October 2002

3. P. Goethals et al. - 9 October 2002
Monitoring methods
Cooling water inlet
Fikes
P. Goethals et al October 2002

4. Reference conditions for the Scheldt estuary
historical data (Poll, 1945, 1947; de Selys-Longchamps, 1842)
data from similar European Estuaries (e.g. Eems-Dollard)
expert knowledge (e.g. OVB, 1988)
recent data collections (Maes, KULeuven)
P. Goethals et al October 2002

5. P. Goethals et al. - 9 October 2002
Reference conditions for the Scheldt estuary (Adriaenssens et al., 2002)
Proposal:
11 freshwater species
10 diadromic species
37 marine species
In total: 58 species
P. Goethals et al October 2002

6. Datacollection &interpretation
Monitoring methods
Spatial and temporal variability
Monitoring frequency
P. Goethals et al October 2002

7. P. Goethals et al. - 9 October 2002
Monitoring methods
Demersal
Benthic
Pelagic
Fikes
Cooling water inlet
P. Goethals et al October 2002

8. Spatial and temporal variability
Total number of species
Date
Location
P. Goethals et al October 2002

9. P. Goethals et al. - 9 October 2002
Monitoring frequency
Frequency
% of the total number of species (based on all catches)
P. Goethals et al October 2002

10. Conclusions for standard monitoring method
Fikes are most convenient (site flexibility, catch efficiency)
Pooling of individual catches is necessary to reduce data variability
P. Goethals et al October 2002

11. Metrics in the Estuariene IBI
Total number of species
Typical species
Trophic structure: Omnivores, piscivores
Tolerance scores (pollution, habitat quality)
Estuarine resident species
Diadromic species
Marine juvenile migrating species
P. Goethals et al October 2002

12. P. Goethals et al. - 9 October 2002
Individual metric scores
P. Goethals et al October 2002

13. P. Goethals et al. - 9 October 2002
Final IBI score
Mean of all individual metric scores
P. Goethals et al October 2002

14. IBI evolution in Bath (95-99)
P. Goethals et al October 2002

15. P. Goethals et al. - 9 October 2002
IBI development
P. Goethals et al October 2002

16. Temporal variability of the score components in Bath (95-99)
P. Goethals et al October 2002

17. P. Goethals et al. - 9 October 2002
Conclusions
Based on fike measurements, a stable and meaningful IBI score could be calculated
The individual score components are useful to make an interpretation of the major causes in fish community shifts
Not yet WFD proof: recruitment & population dynamics to be added
The recent fish community conditions of the Beneden Sea Scheldt are not meeting a good ecological status
P. Goethals et al October 2002

18. P. Goethals et al. - 9 October 2002
Further research
Similar methodology for other Belgian transitional waters
incorporation of freshwater tidal zones
Intercalibration: at national and international level
P. Goethals et al October 2002