Table 1. Environmental parameters and phytoplankton biomass in Lake Akersvannet during the sampling season 2013.
| Environmental Parameters | June | July | August |
|---|---|---|---|
| Temp (°C) * | 17.3 (± 0.3) | 19.1 (± 0.6) | 20.7 (± 2) |
| pH* | 8.2 (± 0.1) | 8.7 (± 0.3) | 8.3 (± 0.5) |
| O2 (%)* | 90 (± 2) | 103 (± 9) | 90 (± 15) |
| Total Nitrogen (mg/l) * | 1.8 (± 164) | 1.7 (± 30) | 1.5 (± 300) |
| Total Phosphorus (μg/l) * | 111(± 12) | 90 (± 47) | 148 (± 57) |
| Ammonia (μg/l) * | 53 (± 92) | 0 | 223 (± 76) |
| Nitrate (μg/l) * | 1590 (± 310) | 1530 (± 62) | 710 (± 16) |
| Chlorophyll a (μg/l) ** | 9 (± 1) | 30 (± 3) | 52 (± 0) |
| Total phytoplankton biomass (mg/l) *** | 0.4 | 1.4 | 16 |
| Biomass of Cyanobacteria (mg/l) *** | 0.1 | 1.2 | 0.1 |
| Cyanobacteria (% of total phytoplankton) | 24 | 77 | 1 |
| Biomass of Ceratium hirundinella (mg/l) *** | 0.04 | 0.05 | 15.4 |
| Ceratium hirundinella (% of total phytoplankton) | 11 | 3.5 | 96 |
| Microcystin (μg/l) ** | <0.15 | <0.15 | 0.5 (± 0.8) |
* mean values for depth 0-4m,
** mean values from photic zone,
*** mixed sample from photic zone.
Numbers in parentheses show standard deviation