[VD07] Phosphorus in lakes
Key message
In Europe, the number of lakes with low phosphorus content and greater transparency is increasing, as a result of measures taken to reduce pressures of to lakes. Similarly the improvement, compared to the situation in seventies, has been observed in Lake Bled as well. But in the last years "blooming" of phytoplankton in the lake appears with increasing frequency, with impact on worse transparency and indicating the increase in trophic status. Lake Bohinj is one of the oligotrophic, flow-through alpine lakes where the effects of man in the lake’s water basin, covering a sparsely populated mountain karst area, are relatively mild. In the artificial reservoirs, especially those in central and northeastern Slovenia, where agriculture is the main activity, the average content of phosphorus is significantly higher and transparency lower than in natural lakes, with no trend of improvement.
Definition
Charts
Standardised Database for Water Quality Monitoring, Environmental Agency of the Republic of Slovenia, 2012
| Blejsko jezero | Bohinjsko jezero | Velenjsko jezero | Šmartinsko jezero | Slivniško jezero | Perniško jezero | Ledavsko jezero | Gajševsko jezero | Ptujsko jezero | Klivnik | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2007 | micro g P/l | 12.7 | 5.2 | 94 | 95 | 85 | 192 | 135 | 222 | 33.8 | 9.2 |
| 2008 | micro g P/l | 11.6 | 3.6 | 30.4 | 48.7 | 29.2 | 126.2 | 103.5 | 88.7 | 58.7 | 9.9 |
| 2009 | micro g P/l | 13.2 | 3.5 | 24.5 | 160.2 | 37.5 | 252.4 | 137.1 | 122 | 35.5 | 15 |
| 2010 | micro g P/l | 11.5 | 4.1 | 54.8 | 46.3 | 22.7 | 179.7 | 69.6 | 112 | 55.1 | 11.6 |
| 2011 | micro g P/l | 10 | 5 | 53 | 36 | 34 | 224 | 64 | 99 | 9 | |
| Mola | Vogršček | Družmirsko jezero | |||||||||
| 2007 | micro g P/l | 19.4 | 9.2 | ||||||||
| 2008 | micro g P/l | 13.7 | 9.2 | ||||||||
| 2009 | micro g P/l | 15.4 | 9.9 | ||||||||
| 2010 | micro g P/l | 10.6 | 8.2 | 52 | |||||||
| 2011 | micro g P/l | 13.2 | 13.7 | 23 |
Standardised Database for Water Quality Monitoring, Environmental Agency of the Republic of Slovenia, 2005
| Blejsko jezero | Bohinjsko jezero | Velenjsko jezero | Šmartinsko jezero | Slivniško jezero | Perniško jezero | Ledavsko jezero | Gajševsko jezero | Ptujsko jezero | Klivnik | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2007 | Secchi depth (m) | 8.3 | 9.2 | 4.8 | 0.8 | 1.1 | 0.2 | 0.3 | 0.4 | 0.6 | 3.1 |
| 2008 | Secchi depth (m) | 6.6 | 9 | 4.6 | 1.1 | 1.3 | 0.5 | 0.5 | 0.5 | 0.7 | 3.3 |
| 2009 | Secchi depth (m) | 5 | 8.3 | 6.8 | 1.4 | 1.5 | 0.4 | 0.5 | 0.5 | 0.5 | 2.3 |
| 2010 | Secchi depth (m) | 4.5 | 8.5 | 6.1 | 1 | 1.2 | 0.4 | 0.5 | 0.5 | 1.2 | 3 |
| 2011 | Secchi depth (m) | 5.9 | 9.5 | 6 | 1.1 | 1.2 | 0.3 | 0.6 | 0.7 | * | 4.1 |
| Mola | Vogršček | Družmirsko jezero | |||||||||
| 2007 | Secchi depth (m) | 2.1 | 1.5 | ||||||||
| 2008 | Secchi depth (m) | 2.4 | 3.1 | ||||||||
| 2009 | Secchi depth (m) | 2 | 2.6 | ||||||||
| 2010 | Secchi depth (m) | 3 | 2.6 | 3.2 | |||||||
| 2011 | Secchi depth (m) | 3.3 | 1.9 | 2.6 |