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