Family: Østers (Ostreidae)
| Year | Arter/grupper | Localities | Participants | Observations |
|---|---|---|---|---|
| 2021 | 1 | 1 | 1 | 2 |
| 2020 | 2 | 1 | 1 | 3 |
| 2019 | 3 | 2 | 2 | 6 |
| 2018 | 2 | 3 | 3 | 3 |
| 2017 | 2 | 5 | 4 | 6 |
| 2016 | 3 | 4 | 3 | 9 |
| 2015 | 3 | 2 | 2 | 9 |
| 2014 | 3 | 7 | 6 | 22 |
| 2013 | 3 | 13 | 12 | 23 |
| 2010 | 1 | 2 | 1 | 2 |
| 2001 | 2 | 1 | 1 | 3 |
| 1996 | 1 | 1 | 6 | 16 |
| Totalt alle år | 4 | 37 | 31 | 104 |