Catchment ara = 4164 ha

Surface area = 47 haMax. depth = 6 m

Reference lake in Wallonia: Falemprise

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.

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

15-M

ay-0

722

-May

-07

30-M

ay-0

75-

Jun-

0713

-Jun

-07

19-J

un-0

727

-Jun

-07

4-Ju

l-07

10-J

ul-0

717

-Jul

-07

25-J

ul-0

731

-Jul

-07

7-A

ug-0

7

17-A

ug-0

721

-Aug

-07

27-A

ug-0

7

3-S

ep-0

7

12-S

ep-0

7

17-S

ep-0

7

24-S

ep-0

7

2-O

ct-0

7

10-O

ct-0

7

16-O

ct-0

7other f ilaments

Anabaena sp.(spiral)

Anabaena sp.

Microcystis sp.

Pseudanabaena sp.Aphanocapsa sp.

LimnothrixAphanizomenon issathschenkoi

Aphanizomenon f los-aquaePlanktothrix agardhii

0.0

5.0

10.0

15.0

20.0

25.0

Ch

loro

ph

yll

a eq

uiv

alen

ts (

µg

/l)

Falemprise 2007 - 0-4 m

Bambois, July 2008

Microcystin in Ri Jaune, 2009

BLOOMNET in Wallonia

0

10

20

30

40

50

60

70

29-Jul-09 5-Aug-09 11-Aug-09 19-Aug-09 27-Aug-09 2-Sep-09 10-Sep-09 17-Sep-09 24-Sep-09

MC

-LR

eq

uiv

ale

nts

(µ

g/l)

Ri Jaune - 2009

soluble

totale

June 20, 2007 Ecaussines

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0.0 20.0 40.0 60.0 80.0

Chla µg L-1

Z (

m)

cyanobacteria T1

cyanobacteria T2

total cyanobacteria

Chlorophyll a

Subcontract with Aquapole – ULgModel simulations

Phosphorus reductions (external loading) will help reduce cyanobacteria blooms

Hydrometeorology 2002Releases 2002 and 2015

Hydrometeorology 2007Releases 2007 and 2015

Groupe I Nostocales

Groupe II Planktothrix

Groupe III Picocyanobactéries

Groupe IV Microcystis

Groupe V Woronichinia

Groupe VI Snowella

100

94

100

100

100100

94

100

78

54

100

100

100

94

Groupe VII Pseudanabaena/Limnothrix

100

82

Genetic diversity of cyanobacteria in Belgian

waterbodies (2007)

In Falemprise, Chérapont, Ecaussines, Ixelles pond II16S rRNA sequences obtained by DGGE (blue)

Green and brown sequences were previously found in Belgium

3 groups are forming blooms and are potentially toxic in Belgian waterbodies

? Invasive species?

Toxin gene detection during a 2-years survey in lake Falemprise

- mcy genes were 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

0,00

2,00

4,00

6,00

8,00

10,00

12,00

Cya

noba

cter

ial b

iom

ass

(µg

eq C

hla/

l)

0%

20%

40%

60%

80%

100%

22 M

ay29

May

04 Ju

ne11

June

18 Ju

ne25

June

03 Ju

ly24

July

01 A

ug07

Aug

14 A

ug21

Aug

04 S

ept

18 S

ept

01 O

ct08

Oct

22 O

ct

Prop

ortio

n of

MC-

LR

Particulate fraction

Soluble fraction

0

1

2

3

4

5

6

7

Tota

l MC

-LR

(µ

g/L)

++ ++++++++++++++++ +++++++++++++-++ ++++++++++++++mcyA

mcyECyano

0%

20%

40%

60%

80%

100%

Pro

portio

n o

f M

C-L

R

Particulate fraction

Soluble fraction

2008

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

4,50

Cya

noba

cter

ial b

iom

ass

(µg

eq C

hla/

l)

0%

20%

40%

60%

80%

100%

30 M

ay

05 J

une

19 J

une

27 J

une

04 J

uly

10 J

uly

25 J

uly

31 J

uly

07 A

ug

17 A

ug

21 A

ug

27 A

ug

03 S

ept

12 S

ept

17 S

ept

24 S

ept

02 O

ct

10 O

ct

16 O

ct

Prop

ortio

n of

MC-

LR

Particulate fractionSoluble fraction

+++++++++++++++++++

+++----+++++++++---

---------++++++----mcyA

mcyE

0,00

0,50

1,00

1,50

2,00

2,50

3,00

Con

cent

ratio

n of

MC

-LR

(µg/

l)

Cyano

0%

20%

40%

60%

80%

100%

30 M

ay

05 J

une

19 J

une

27 J

une

04 J

uly

10 J

uly

25 J

uly

31 J

uly

07 A

ug

17 A

ug

21 A

ug

27 A

ug

03 S

ept

12 S

ept

17 S

ept

24 S

ept

02 O

ct

10 O

ct

16 O

ct

Pro

port

ion o

f M

C-L

R

Particulate fractionSoluble fraction

2007

Particulate MC-LR

Soluble MC-LR

Park Westveld, Sint-Amandsberg

• 99 samples (2007-2008, 2009)

• microscopical analysis:

cyanobacteriaphytoplanktongrazers and parasites

• molecular analysis Microcystis (ITS rDNA)

Microcystis bloom dynamics in Westveld Pond

15-05-07

30-05-07

14-06-07

29-06-07

14-07-07

29-07-07

13-08-07

28-08-07

12-09-07

27-09-07

12-10-07

27-10-07

11-11-07

26-11-07

11-12-07

26-12-07

10-01-08

25-01-08

09-02-08

24-02-08

10-03-08

25-03-08

09-04-08

24-04-08

09-05-08

24-05-08

08-06-08

23-06-08

08-07-08

23-07-08

07-08-08

22-08-08

06-09-08

21-09-08

06-10-08

21-10-080

5000

10000

15000

20000

25000solitary Microcystis cellsMicrocystis aeruginosaMicrocystis viridis

µg C

L-1

16S-23S rDNA ITS sequences

Strong effects of naked amoebae on Microcystis biomass

15-05-07

31-05-07

16-06-07

02-07-07

18-07-07

03-08-07

19-08-07

04-09-07

20-09-07

06-10-07

22-10-07

07-11-07

23-11-07

09-12-07

25-12-07

10-01-08

26-01-08

11-02-08

27-02-08

14-03-08

30-03-08

15-04-08

01-05-08

17-05-08

02-06-08

18-06-08

04-07-08

20-07-08

05-08-08

21-08-08

06-09-08

22-09-08

08-10-08

24-10-080

5000

10000

15000

20000

25000 Microcystis aeruginosa

Microcystis viridis

µg C

L-1

N ml-1

0

10000

20000

30000

40000

50000

60000

70000

80000

amoebae

First detection of Cylindrospermopsis raciborskii in Belgium

• August 2009• Zonhoven and Averbode• 20 – 27 µg microcystin L-1

• urban context• heavy pollution (nutrients)• high productivity• cyanobacteria Blooms

– cyanotoxins present at all times– sometimes at alarming concentrations

BruxellesA large number of ponds

• 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

Bruxelles Predictive model

– management tool

Before

After

Prediction of microcystin concentration from the B-BLOOMS2 data set

method: classification and regression tree (CART)

0 20 40 60 80 100

05

1525

Microcystis.Cyano (97.1%)

fitte

d fu

nctio

n

Total_MC - page 1

0.0 1.0 2.0 3.0

05

1525

ZEU (1.1%)fit

ted

func

tion

0 200 600 1000

05

1525

TP (0.9%)

fitte

d fu

nctio

n

0 100 300 500

05

1525

DIN (0.3%)

fitte

d fu

nctio

n

0 100 300 500

05

1525

CyanoT2 (0.3%)

fitte

d fu

nctio

n

0 500 1500 2500

05

1525

NbreClado (0.1%)

fitte

d fu

nctio

n

0 200 400 600 800

05

1525

NbreGdsClado (0.1%)fit

ted

func

tion

0 50 150 250

05

1525

CyanoT1 (0%)

fitte

d fu

nctio

n

0 10 30 50 70

05

1525

NO3 (0%)

fitte

d fu

nctio

n

0 50 100 150 200

05

1525

NbreCopépodites (0%)

fitte

d fu

nctio

n

0 20 40 60 80 100

05

1525

Planktothrix.Cyano (0%)

fitte

d fu

nctio

n

0 200 400 600 800

05

1525

NbreCopépodes (0%)fit

ted

func

tion

y = 0.384x - 57.706

R2 = 0.6257

-200

0

200

400

600

800

1000

0 200 400 600 800 1000 1200 1400

TP

Cya

no

To

t

Lacs Flandres Bruxelles

FP

Linéaire (Lacs Flandres Bruxelles)

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