Species: Hjertetjernaks (Potamogeton perfoliatus)
| Year | Arter/grupper | Localities | Participants | Observations |
|---|---|---|---|---|
| 2013 | 1 | 1 | 1 | 1 |
| 2005 | 1 | 1 | 1 | 1 |
| 2004 | 1 | 4 | 3 | 4 |
| 2003 | 1 | 1 | 1 | 1 |
| 1996 | 1 | 1 | 1 | 1 |
| 1993 | 1 | 2 | 2 | 2 |
| 1992 | 1 | 2 | 2 | 2 |
| 1991 | 1 | 3 | 3 | 3 |
| 1990 | 1 | 1 | 1 | 1 |
| 1989 | 1 | 7 | 6 | 7 |
| Totalt alle år | 1 | 20 | 18 | 23 |