KAZALCI OKOLJA

Key message
Neutral

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 and their contributing areas. Compared to the situation in seventies, after the introduction of recovery measures, improvement has been observed in Lake Bled as well, however overburden with phosphorous compounds is still occasionally present, with impact on increased phytoplankton biomass and reduced transparency of the lake. 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. The concentration of phosphorous is relatively low and reduces the productivity of phytoplankton. In the artificial reservoirs, especially those in central and north-eastern 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.



Charts

Figure VD07-1: Average (annual) concentration of the entire phosphorus load in selected lakes expressed in µg P/l
Sources:

Standardised Database for Water Quality Monitoring, Environmental Agency of the Republic of Slovenia, 2014

Show data
Blejsko jezero Bohinjsko jezero Velenjsko jezero Družmirsko jezero Šmartinsko jezero Slivniško jezero Perniško jezero Ledavsko jezero Gajševsko jezero Ptujsko jezero
2007 micro g P/l 12.7 5.2 94 95 85 192 135 222 33.8
2008 micro g P/l 11.6 3.6 30.4 48.7 29.2 126.2 103.5 88.7 58.7
2009 micro g P/l 13.2 3.5 24.5 160.2 37.5 252.4 137.1 122 35.5
2010 micro g P/l 11.5 4.1 54.8 52 46.3 22.7 179.7 69.6 112 55.1
2011 micro g P/l 10 5 53 23 36 34 224 64 99
2012 micro g P/l 13.3 5.3 49.4 23 29.7 41.6 306.6 99.7 109.5
2013 micro g P/l 11.2 6.2 60.3 12.3 36.9 50.4 343.4 123.1 129.7
Klivnik Mola Vogršček
2007 micro g P/l 9.2 19.4 9.2
2008 micro g P/l 9.9 13.7 9.2
2009 micro g P/l 15 15.4 9.9
2010 micro g P/l 11.6 10.6 8.2
2011 micro g P/l 9 13.2 13.7
2012 micro g P/l 12.1 18.4 16.3
2013 micro g P/l 9.3 12.7 14.9
Figure VD07-2: Average transparency of selected lakes
Sources:

Standardised Database for Water Quality Monitoring, Environmental Agency of the Republic of Slovenia, 2014

Show data
Blejsko jezero Bohinjsko jezero Velenjsko jezero Družmirsko jezero Šmartinsko jezero Slivniško jezero Perniško jezero Ledavsko jezero Gajševsko jezero Ptujsko jezero
2007 Secchi depth (m) 8.3 9.2 4.8 0.8 1.1 0.2 0.3 0.4 0.6
2008 Secchi depth (m) 6.6 9 4.6 1.1 1.3 0.5 0.5 0.5 0.7
2009 Secchi depth (m) 5 8.3 6.8 1.4 1.5 0.4 0.5 0.5 0.5
2010 Secchi depth (m) 4.5 8.5 6.1 3.2 1 1.2 0.4 0.5 0.5 1.2
2011 Secchi depth (m) 5.9 9.5 6 2.6 1.1 1.2 0.3 0.6 0.7
2012 Secchi depth (m) 6.7 9.9 6.7 3.4 1.4 1.2 0.3 0.6 0.5
2012 Secchi depth (m) 6.2 8.3 6.5 3.7 1.3 0.9 0.3 0.6 0.5
Klivnik Mola Vogršček
2007 Secchi depth (m) 3.1 2.1 1.5
2008 Secchi depth (m) 3.3 2.4 3.1
2009 Secchi depth (m) 2.3 2 2.6
2010 Secchi depth (m) 3 3 2.6
2011 Secchi depth (m) 4.1 3.3 1.9
2012 Secchi depth (m) 2.6 2.4 1.4
2012 Secchi depth (m) 4.7 3 2.2