[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 three years "blooming" of phytoplankton in the lake appears with increasing frequency, reflecting the increase in trophic status and the impact of worse transparency. 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, 2010
| 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 |
| povprečje 2005 -2009 | micro g P/l | 12.9 | 4.2 | 49.6 | 101.6 | 86.3 | 152.4 | 149.1 | 133.4 | 42.6 | 11.8 |
| Mola | Vogršček | ||||||||||
| 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 | ||||||||
| povprečje 2005 -2009 | micro g P/l | 15.6 | 9.4 |
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 |
| average 2005 -2009 | Secchi depth (m) | 6.8 | 9.2 | 5.4 | 1 | 1.2 | 0.3 | 0.5 | 0.5 | 0.6 | 2.9 |
| Mola | Vogršček | ||||||||||
| 2007 | Secchi depth (m) | 2.1 | 1.5 | ||||||||
| 2008 | Secchi depth (m) | 2.4 | 3.1 | ||||||||
| 2009 | Secchi depth (m) | 2 | 2.6 | ||||||||
| average 2005 -2009 | Secchi depth (m) | 2.3 | 2.4 |