Table 1.
Water quality and zooplankton parameters across the studied turbidity classes (mean ± SD).
| LT | MT | HT | P | ||||
|---|---|---|---|---|---|---|---|
| ± SD | ± SD | ± SD | |||||
| Physical and chemical parameters of water | |||||||
| Turbidity (NTU) | 12.58a | 7.34 | 18.67b | 9.99 | 31.83c | 17.87 | 0.000 |
| SDT (m) | 1.18a | 0.38 | 0.74b | 0.20 | 0.54c | 0.14 | 0.000 |
| Color (Hazen) | 10.10a | 6.99 | 18.03b | 13.51 | 23.87b | 19.10 | 0.000 |
| Tot susp (mg/l) | 4.35a | 3.05 | 6.84ab | 5.60 | 9.03b | 6.99 | 0.000 |
| In susp (mg/l) | 1.27a | 1.26 | 2.76ab | 3.02 | 3.24b | 3.49 | 0.003 |
| Org susp (mg/l) | 3.08a | 2.47 | 4.08ab | 4.90 | 5.79b | 5.93 | 0.019 |
| Chl a (µg/l) | 3.46a | 4.43 | 4.49ab | 2.97 | 6.16b | 6.81 | 0.027 |
| Temperature (°C) | 17.44 | 3.06 | 16.71 | 4.87 | 17.08 | 4.36 | > 0.05 |
| pH | 7.74 | 0.26 | 7.78 | 0.32 | 7.80 | 0.27 | > 0.05 |
| DO (mg/l) | 8.29 | 1.41 | 8.74 | 1.24 | 8.66 | 0.93 | > 0.05 |
| TP (mg/l) | 0.12 | 0.06 | 0.11 | 0.11 | 0.11 | 0.06 | > 0.05 |
| TN (mg/l) | 0.22 | 0.10 | 0.28 | 0.12 | 0.30 | 0.12 | > 0.05 |
| Zooplankton measures | |||||||
| Biomass (mg/l) | 0.122a | 0.269 | 8.02b | 12.42 | 3.66c | 6.76 | 0.000 |
| Abundance (ind./l) | 105.9a | 407.7 | 1265.5b | 1555.4 | 751.4c | 1345.20 | 0.000 |
| Number of species (ind.) | 17a | 5 | 17a | 4 | 15b | 5 | 0.009 |
| Shannon’s biodiversity index H′ | 1.99a | 0.58 | 1.64b | 0.39 | 1.62b | 0.45 | 0.000 |
| Pielou’s eveness index, J′ | 0.714a | 0.192 | 0.583b | 0.127 | 0.622b | 0.175 | 0.001 |
Differences in the analysed parameters were determined by ANOVA (df = 157; P ≤ 0.05); values with the different superscripts are different among reservoirs by post-hoc Tukey test.
SDT Secchi depth, Tot susp total suspended solids, In susp inorganic suspended solids, Org susp organic suspended solids, Chl a chlorophyll a, DO dissolved oxygen, TP total phosphorus, TN total nitrogen.