| Report Year: 2007 |
| Big Spirit Lake, Dickinson County |
| Summary Data Table |
| 011: BSL 54 012: BSL 54.1 013: BSL 54.2 014: BSL 54.3 015: BSL 54.4 |
| Parameter | 6/4
(011) | 6/4
(012) | 6/4
(013) | 6/4
(014) | 6/4
(015) | 6/19
(011) | 6/19
(012) | 6/19
(013) | 6/19
(014) | 6/19
(015) | 7/9
(011) | 7/9
(012) | 7/9
(013) | 7/9
(014) | 7/9
(015) | 7/17
(011) | 7/17
(012) | 7/17
(013) | 7/17
(014) | 7/17
(015) | 8/13
(011) | 8/13
(012) | 8/13
(013) | 8/13
(014) | 8/13
(015) | 8/21
(011) | 8/21
(012) | 8/21
(013) | 8/21
(014) | 8/21
(015) | 9/12
(011) | 9/12
(012) | 9/12
(013) | 9/12
(014) | 9/12
(015) | 2007 | 2006 | 2005 |
| Secchi Disk Depth (m) | 1.6 | 1.4 | 1.7 | 1.6 | 1.6 | 1.0 | 0.9 | 1.0 | 1.0 | 1.0 | 1.0 | 0.9 | 0.9 | 1.0 | 1.3 | 1.3 | 1.7 | 1.4 | 1.4 | 1.4 | 1.1 | 0.9 | 1.0 | 0.9 | 1.1 | 1.4 | 2.2 | 1.7 | 1.8 | 1.4 | 0.9 | 0.8 | 1.2 | 0.9 | 0.8 | 1.2 | 1.8 | 1.5 |
| Temperature(oC) | 19.0 | 19.0 | 19.0 | 19.0 | 18.5 | 22.0 | 22.0 | 22.0 | 22.5 | 22.5 | 24.5 | 25.6 | 25.4 | 25.5 | 23.8 | 24.5 | 25.0 | 24.5 | 24.0 | 24.0 | 24.5 | 24.5 | 25.0 | 25.0 | 24.5 | 24.0 | 27.0 | 24.0 | 24.0 | 24.0 | 19.6 | 19.4 | 19.8 | 19.7 | 19.4 | 22.8 | 23.7 | 23.3 |
| Dissolved Oxygen (mg/L) | 8.5 | 9.1 | 8.9 | 9.0 | 8.9 | 7.4 | 6.1 | 6.1 | 7.4 | 7.1 | 6.4 | 7.2 | 6.6 | 7.0 | 5.1 | 7.6 | 8.0 | 8.0 | 7.6 | 8.0 | 7.6 | 8.1 | 8.1 | 7.9 | 7.7 | 8.0 | 8.2 | 8.2 | 9.3 | 7.6 | 7.6 | 5.8 | 5.9 | 6.5 | 6.7 | 7.5 | 9.4 | 8.5 |
| Dissolved Oxygen Saturation (%) | 92 | 98 | 96 | 97 | 95 | 85 | 70 | 70 | 85 | 82 | 77 | 88 | 80 | 85 | 60 | 91 | 97 | 96 | 90 | 95 | 91 | 97 | 98 | 96 | 92 | 95 | 103 | 97 | 110 | 90 | 83 | 63 | 65 | 71 | 73 | 87.3 | 111.4 | 99.2 |
| Chlorophyll a (μg/L) | 12.9 | 17.7 | 19.7 | 17.2 | 11.7 | 13.4 | 19.7 | 17.5 | 20.2 | 18.9 | 37.1 | 55.1 | 45.1 | 40.0 | 5.7 | 85.0 | 23.0 | 50.7 | 48.0 | 41.5 | 29.0 | 31.1 | 30.4 | 29.0 | 34.5 | 23.0 | 21.4 | 29.5 | 49.6 | 18.9 | 22.4 | 16.1 | 13.3 | 19.0 | 20.2 | 28.2 | 14.2 | 63.6 |
| Total Phosphorus as P (μg/L) | 26 | 22 | 27 | 24 | 24 | 30 | 23 | 25 | 24 | 58 | 67 | 24 | 53 | 47 | 91 | 80 | 45 | 55 | 63 | 62 | 49 | 47 | 43 | 53 | 53 | 55 | 50 | 52 | 80 | 50 | 57 | 55 | 30 | 21 | 21 | 45 | 46 | 54 |
| Total Nitrogen as N (mg/L) | 0.95 | 1.06 | 0.99 | 0.95 | 0.97 | 0.55 | 0.55 | 0.64 | 0.55 | 0.48 | 1.36 | 1.33 | 0.49 | 0.48 | 1.04 | 1.45 | 1.08 | 1.10 | 1.19 | 1.18 | 0.73 | 0.74 | 0.76 | 0.73 | 0.65 | 0.76 | 0.75 | 0.66 | 1.16 | 0.59 | 1.05 | 1.13 | 1.07 | 1.08 | 0.92 | 0.89 | 0.88 | 1.12 |
| Microcystin (ng/L) | 15.3 | - | - | - | - | 3.6 | - | - | - | - | 12.0 | - | - | - | - | 57.2 | - | - | - | - | 52.0 | - | - | - | - | 42.7 | - | - | - | - | 45.1 | - | - | - | - | 32.6 | 1.3 | 4.4 |
| Carlson Trophic State Index (Secchi)* | 54 | 55 | 53 | 53 | 53 | 60 | 61 | 60 | 60 | 60 | 61 | 62 | 62 | 61 | 56 | 57 | 53 | 56 | 56 | 56 | 59 | 62 | 61 | 62 | 59 | 55 | 49 | 53 | 52 | 55 | 62 | 64 | 58 | 62 | 64 | 57 | 51 | 54 |
| Carlson Trophic State Index (Chl a)* | 56 | 59 | 60 | 59 | 55 | 56 | 60 | 59 | 60 | 59 | 66 | 70 | 68 | 67 | 48 | 74 | 61 | 69 | 69 | 67 | 64 | 64 | 64 | 64 | 65 | 61 | 61 | 64 | 69 | 59 | 61 | 58 | 56 | 59 | 60 | 63 | 57 | 71 |
| Carlson Trophic State Index (TP)* | 51 | 49 | 52 | 50 | 50 | 53 | 50 | 51 | 50 | 63 | 65 | 50 | 61 | 60 | 69 | 67 | 59 | 62 | 64 | 64 | 60 | 60 | 58 | 62 | 61 | 62 | 61 | 61 | 67 | 61 | 62 | 62 | 53 | 48 | 48 | 59 | 59 | 62 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |
| Carlson Trophic State Index Definition |