Measuring the impact degree of different pressure types with the Benthic
Ecosystem Quality Index (BEQI) H:25
1
2
Gert Van
1
Hoey ,
EU Framework Directives
(marine environment)
• Water Framework Directive
• Marine Strategy Directive
• Habitat and Bird Directives
Healthy ecosystems where
anthropogenic influences
are well-managed
Tom
2
Ysebaert
and Kris
1
Hostens
Evaluation of the
environment
Benthic Ecosystem
Quality index (BEQI)
• Impact assessment
• Physical disturbance (fisheries,
sand extraction, dredging)
• Pollution (chemicals,
nutrients)
• Construction works (harbours
wind farms, coastal defense)
• Recovery assessment
• Benthic indicator tool
• Scaled the deviation between
control and impact data in 5
classes
• Sampling effort based
• Evaluate benthic parameters:
density, biomass, number of
species, similarity (species
composition) www.beqi.eu
MEASURING IMPACT DEGREES: CASE STUDIES
Average BEQI EQR value per habitat
90,00
1.0
< 2m t.o.v NAP
Oxygen <<7mg/l
zuurstof
7 mg/l
Oxygen <<2mg/l
zuurstof
2 mg/l
Average
EQR
2 - 8m t.o.v. NAP
> 8m t.o.v. NAP
80,00
0.6
50,00
0.4
40,00
BEQI-score
Percentage surface
0.2
Similarity EQR
60,00
(Poor)
0.8
70,00
0.6
E
Q
R 0.4
0.39
Number of
species EQR
0.43
(Moderate)
0.53
(Moderate)
30,00
Density EQR
0.2
20,00
0.61
0
2000000
4000000
6000000
8000000
10000000
12000000
0,00
Dumping quantity (Tonnes Dry Matter) per year
0.0
1995
Source: Van Hoey, G., Hostens, K., Parmentier, K., Robbens, J., Bekaert, K., De Backer, A., Derweduwen,
J., Devriese, L., Hillewaert, H., Hoffman, S., Pecceu, E., Vandendriessche, S., Wittoeck, J., 2010. Biological
and chemical effects of the disposal of dredged material in the Belgian Part of the North Sea (period
2007-2008). Report ILVO-Animal Science-Fisheries 1, pp. 97.
Biomass EQR
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
Restoration measures
Source Van Hoey et al., 2007. The Benthic Ecosystem Quality Index, intercalibration and assessment of
Dutch Coastal and transitional waters for the Water Framework Directive, NIOO-report 2007-02
1
(Good)
10,00
0
Reference period 1983-1990
Species
“Holland” coast 1991-2001
“Holland” coast 2002-2004
“Wadden” coast 1991-2001
“Wadden” coast 2002-2004
0.0
(Bad)
Ensis AFDW
Biomass EQR
0.8
200
0.6
150
0.4
100
0.2
50
0
Evaluation of the impact at 5 dredge disposal  Ecological status in Lake Veere bad, mainly in
250
g AFDW
Similarity
Number of species
Density
Average EQR score
0.8
Evaluation “Wadden”
coast (2002-2004)
Lake Veere, time serie
BEQI EQR scores versus dumping intensity
1
Alien species (Ensis directus) (NL coast)
Organic enrichment (Lake Veere, NL)
BEQI biomass EQR
Dumping of dredged material (BE)
0
ref
1993-1995 1996-1998 1999-2001 2002-2004
Source: Van Hoey et al., 2007. The Benthic Ecosystem Quality Index, intercalibration and assessment of
Dutch Coastal and transitional waters for the Water Framework Directive, NIOO-report 2007-02
sites (2006-2008) in Belgian Coastal waters
the deepest habitat (< 8m) due to oxygen
Due to the dominance of Ensis directus in fine
 Benthic community impacted (EQR < 0.6)
depletion as a consequence of eutrophication
sandy sediments at Wadden Coast (2002-2004):
and stratification
Benthos species composition changed
from a dumping intensity of 1 to 2 million
 Similarity EQR moderate
 Management action: again water exchange
tones dry matter per year
 Impact strongest on the parameter density
through inlet in Oosterschelde dam
 Number of species less impacted
 Benthos recovery in deepest habitat
 Chronic dumping prevent the development
 Other habitats still affected, partly due
of a healthy, stable benthic community
 Biomass quadrupled in last 10 years
 Biomass EQR bad
 Number of species slightly decreased
to changed salinity patterns
The need for adequate control/reference areas
 Number of species EQR moderate
Sampling strategy spatially and temporally adapted to impact type
Impact assessment: Points of attention !!
Biological assessment has to coincide with detailed knowledge on
impact frequency and intensity
Indicators summarize patterns, but they do not provide full explanations
of observed patterns
CONCLUSION
 Indicators are evidence based tools which can be used for the evaluation of anthropogenic impacts in marine systems.
 The BEQI indicator tool is capable of measuring the impact degree of different pressure types. The different BEQI parameters
combined in the tool, however, may react differently (the degree of impact) on exerted pressures.
Institute for Agricultural and Fisheries Research, Animal Sciences – Fisheries
ILVO, Biological Environmental Research, Ankerstraat 1, 8400 Oostende, Belgium
 +32(0)59/569 847 gert.vanhoey@ilvo.vlaanderen.be