| Species | Year | RDB of Japan | RDB of Miyagi Prefecture | ||||
| 2014 | 2015 | 2016 | |||||
| Transplant plot | Control plot | Transplant plot | Control plot | ||||
| Monochoria korsakowii | Observed | Not observed | Observed | Observed | Observed | NT |
|
| Ottelia alismoides | Observed | Not observed | Not observed | Not observed | Observed | VU | NT |
| Chara braunii | Observed | Not observed | Not observed | Not observed | Observed | VU |
|
| Najas graminea | Not observed | Not observed | Not observed | Not observed | Not observed |
| VU |
| Najas minor | Not observed | Not observed | Not observed | Not observed | Not observed | VU | CR+EN |
| Salvinia natans | Not observed | Not observed | Observed | Not observed | Not observed | VU |
|
| Alisma plantago-aquatica | Observed | Not observed | Observed | Not observed | Observed |
| NT |