Table 1 Annual average values of physico-chemical factors and TSI (±SE) in Lake Jinghu and Lake Xiyanghu.

Water temperature (WT) (°C)

18.87 ± 1.90

19.00 ± 1.98

pH Value

8.26 ± 0.08

8.45 ± 0.10

Secchi-disk (SD) (m)

0.77 ± 0.015*

0.37 ± 0.03*

Chlorophyll-a concentration (µg/L)

58.57 ± 2.87*

188.52 ± 25.81*

TP (mg/L)

0.07 ± 0.007*

0.41 ± 0.04*

PO₄ ³⁻ (mg/L)

0.04 ± 0.007*

0.23 ± 0.03*

TN (mg/L)

0.83 ± 0.08*

7.34 ± 1.95*

NO₃ ⁻-N (mg/L)

0.06 ± 0.03*

0.52 ± 0.11*

NH₄ ⁺-N (mg/L)

0.07 ± 0.02*

0.88 ± 0.30*

Comprehensive trophic state index (TSI)

51.00 ± 0.73*

63.24 ± 1.54*