Catchment ara = 4164 ha

1. Reference lake in Wallonia: Falemprise Catchment ara = 4164 ha Surface area = 47 ha Max. depth = 6 m Lake Falemprise is one of the Eau d’Heure Lakes and is an official swimming area in the Walloon Region. Therefore, this lake is monitored for microbiological quality by the Walloon authorities.

2. Other taxa present in the samples : Microcystis aeruginosa, Anabaena sp and Limnothrix sp, with Gomphosphaeriumsp and Aphanocapsa sp more sporadically. In 2008, no Planktothrix, but Microcystis

3. BLOOMNET in Wallonia Bambois, July 2008 Microcystin in Ri Jaune, 2009

4. Subcontract with Aquapole – ULgModel simulations Phosphorus reductions (external loading) will help reduce cyanobacteria blooms Hydrometeorology 2002 Releases 2002 and 2015 Hydrometeorology 2007 Releases 2007 and 2015

5. Groupe II Planktothrix Groupe I Nostocales 100 94 Groupe III Picocyanobactéries 100 100 Groupe IV Microcystis 54 100 Groupe V Woronichinia 100 Groupe VI Snowella 100 100 100 94 Groupe VII Pseudanabaena/ Limnothrix 94 100 78 82 100 Genetic diversity of cyanobacteria in Belgian waterbodies (2007) In Falemprise, Chérapont, Ecaussines, Ixelles pond II 16S rRNA sequences obtained by DGGE (blue) Green and brown sequenceswere previously found in Belgium 3 groups are forming blooms and are potentially toxic in Belgian waterbodies ? Invasive species?

6. 2007 2008 mcyA - - - - + + + + + + - - - - - - - - - mcyA + + + + + + + + + + + + + + + + mcyE - - - + + + + + + + + + - - - - + + + mcyE - + + + + + + + + + + + + + + + Cyano Cyano + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Toxin gene detection during a 2-years survey in lake Falemprise • mcy geneswere always detected when the toxin seems to be in the • cyanobacterial cells/biomass • mcy genes were detected even when the biomass was low in 2008 • = Efficient early warning tool Particulate MC-LR Soluble MC-LR

7. Park Westveld, Sint-Amandsberg • 99 samples (2007-2008, 2009) • microscopical analysis: • cyanobacteria • phytoplankton • grazers and parasites • molecular analysis Microcystis • (ITS rDNA)

8. Microcystis bloom dynamics in Westveld Pond 16S-23S rDNA ITS sequences

9. Strong effects of naked amoebae on Microcystis biomass amoebae N ml-1

10. First detection of Cylindrospermopsis raciborskii in Belgium • August 2009 • Zonhoven and Averbode • 20 – 27 µg microcystin L-1

11. Bruxelles A large number of ponds urban context heavy pollution (nutrients) high productivity cyanobacteria Blooms cyanotoxins present at all times sometimes at alarming concentrations

12. Bruxelles Before After Predictive model – management tool Probability of bloom occurrence Identification of ponds at risk of developing cyanobacteria setup of monitoring programs Bloom reduction and restoration of the most affected ponds by approriate techniques

13. Total_MC - page 1 25 25 25 25 fitted function fitted function fitted function fittedfunction 15 15 15 15 5 5 5 5 0 0 0 0 0 20 40 60 80 100 0.0 1.0 2.0 3.0 0 200 600 1000 0 100 300 500 Microcystis.Cyano (97.1%) ZEU (1.1%) TP (0.9%) DIN (0.3%) 25 25 25 25 fitted function fitted function fitted function fitted function 15 15 15 15 5 5 5 5 0 0 0 0 0 100 300 500 0 500 1500 2500 0 200 400 600 800 0 50 150 250 CyanoT2 (0.3%) NbreClado (0.1%) NbreGdsClado (0.1%) CyanoT1 (0%) 25 25 25 25 fitted function fitted function fitted function fitted function 15 15 15 15 5 5 5 5 0 0 0 0 0 10 30 50 70 0 50 100 150 200 0 20 40 60 80 100 0 200 400 600 800 NO3 (0%) NbreCopépodites (0%) Planktothrix.Cyano (0%) NbreCopépodes (0%) Prediction of microcystin concentration from the B-BLOOMS2 data set method: classification and regression tree (CART)

14. In hyper-eutrophic lakes, the best predictor of cyanobacteria biomass is … Total phosphorus