Species: Nordskivesnegl (Gyraulus acronicus)
| Year | Arter/grupper | Localities | Participants | Observations |
|---|---|---|---|---|
| 2009 | 1 | 1 | 1 | 4 |
| 2008 | 1 | 1 | 1 | 1 |
| 2004 | 1 | 1 | 1 | 1 |
| 1996 | 1 | 7 | 6 | 9 |
| 1995 | 1 | 10 | 10 | 11 |
| 1994 | 1 | 7 | 7 | 7 |
| 1993 | 1 | 23 | 24 | 26 |
| 1992 | 1 | 15 | 16 | 18 |
| 1991 | 1 | 3 | 3 | 3 |
| 1990 | 1 | 21 | 21 | 28 |
| 1989 | 1 | 14 | 14 | 14 |
| Totalt alle år | 1 | 51 | 47 | 122 |