Okeechobee (1994 – 2004)
Taihu (1998 – 2002)
50
Taihu
45
Okeechobee
40
TN:TP
35
30
25
20
15
10
5
0
1
2
3
4
5
7
6
Month
8
9
10
11
12
3.0
Taihu
Okeechobee
2.5
NH4+:NOx
2.0
1.5
1.0
0.5
0.0
1
2
3
4
5
6
7
Month
8
9
10
11
12
A
Proportion of total phytoplankton
1.0
Diatoms
0.9
Cyanos
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1
2
3
4
5
7
6
Month
8
9
10
11
12
Proportion of total phytoplankton
B
Cryptos
1.0
Diatoms
0.9
Cyanos
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1
2
3
4
5
7
6
Month
8
9
10
11
12
Proportion of total phytoplankton
A
0.8
Cyano
0.7
Diatoms
0.6
0.5
0.4
0.3
0.2
0.1
0
13
15
17
19
TN:TP
21
23
B
Proportion of total phytoplankton
0.7
Cyano
0.6
Diatoms
0.5
0.4
0.3
0.2
0.1
0
13
18
23
28
TN:TP
33
38
43
A
Proportion of total phytoplankton
0.8
Cyano
0.7
Diatoms
0.6
0.5
0.4
0.3
0.2
0.1
0
0.3
0.6
0.9
1.2
NH4+:NOx
1.5
1.8
2.1
2.4
B
Proportion of total phytoplankton
0.7
Cyano
0.6
Diatoms
0.5
0.4
0.3
0.2
0.1
0
0.4
0.6
0.8
1.0
1.2
1.4
NH4+:NOx
1.6
1.8
2.0
2.2
Taihu
Really big lake…
Really big problems…
Can we get $$$ to study it???
1. Reduce external loading
2. Reduce external loading
3. Reduce external loading
4. Reduce external loading
5. Nutrient cycling rate measurements are
important, but they have to be as realistic as
possible (mimic sediment resuspension)
6. Need nutrient limitation bioassays, but must
be done with different N forms.
7. Nutrient cycling/toxicity connections