Genus: Pea clam (Pisidium)
| Year | Arter/grupper | Localities | Participants | Observations |
|---|---|---|---|---|
| 2013 | 2 | 8 | 8 | 11 |
| 2012 | 1 | 2 | 2 | 2 |
| 2010 | 1 | 1 | 1 | 1 |
| 2008 | 1 | 2 | 2 | 3 |
| 2007 | 1 | 1 | 1 | 1 |
| 1998 | 1 | 1 | 1 | 1 |
| 1996 | 1 | 8 | 6 | 9 |
| 1995 | 1 | 5 | 5 | 7 |
| 1994 | 1 | 5 | 5 | 5 |
| 1993 | 1 | 20 | 20 | 24 |
| 1992 | 1 | 21 | 20 | 24 |
| 1991 | 1 | 2 | 2 | 2 |
| 1990 | 1 | 32 | 31 | 43 |
| 1989 | 1 | 26 | 26 | 26 |
| Totalt alle år | 2 | 78 | 73 | 159 |