Catchment ara = 4164 ha
description
Transcript of Catchment ara = 4164 ha
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
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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
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25-03-08
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09-05-08
24-05-08
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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
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23-11-07
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27-02-08
14-03-08
30-03-08
15-04-08
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17-05-08
02-06-08
18-06-08
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5000
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25000 Microcystis aeruginosa
Microcystis viridis
µg C
L-1
N ml-1
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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
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1525
Microcystis.Cyano (97.1%)
fitte
d fu
nctio
n
Total_MC - page 1
0.0 1.0 2.0 3.0
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1525
ZEU (1.1%)fit
ted
func
tion
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1525
TP (0.9%)
fitte
d fu
nctio
n
0 100 300 500
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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
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1525
NbreClado (0.1%)
fitte
d fu
nctio
n
0 200 400 600 800
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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
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1000
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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