| Report Year: 2009 |
| Hawthorn Lake (Barnes City Lake), Mahaska County |
| Phytoplankton |
| | 6/16/2009 | 7/20/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Division | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) | Wet Mass (mg/L) |
| Bacillariophyta | 3.111 | 3.211 | 3.161 | 0.000 | 0.000 | 1.350 | 0.263 | 1.528 | 0.221 | 1.593 | 0.392 |
| Chlorophyta | 0.604 | 0.522 | 0.563 | 0.000 | 0.000 | 0.860 | 1.029 | 1.280 | 0.000 | 0.302 | 2.891 |
| Chrysophyta | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.517 | 0.000 | 0.000 | 0.000 | 0.000 |
| Cryptophyta | 0.553 | 1.500 | 1.027 | 0.000 | 0.000 | 1.629 | 0.130 | 0.056 | 0.022 | 0.349 | 0.375 |
| Cyanobacteria | 81.047 | 185.369 | 133.208 | 0.000 | 0.000 | 1.999 | 26.519 | 14.713 | 321.615 | 6.365 | 8.500 |
| Dinophyta | 0.000 | 7.998 | 3.999 | 0.000 | 0.000 | 1.714 | 0.000 | 1.029 | 1.852 | 3.458 | 11.248 |
| Euglenophyta | 0.000 | 0.480 | 0.240 | 0.000 | 0.000 | 1.999 | 0.006 | 0.007 | 0.024 | 0.000 | 0.005 |
| Total | 85.315 | 199.080 | 142.197 | 0.000 | 0.000 | 9.552 | 28.464 | 18.614 | 323.734 | 12.067 | 23.411 |
| Taxonomic Richness | 20 | 42 | 31 | 0 | 0 | 19 | 8 | 8 | 5 | 9 | 7 |
| Cyanobacteria Cell Counts(k)/ml | 58.645 | 138.238 | 98.442 | 0.000 | 0.000 | 5.220 | 48.763 | 38.299 | 312.085 | 31.226 | 33.532 |
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