| Impact ID | 7741 |
| Impact Type | Predation/Herbivory |
| Study Type | Observational |
| Study Location | Field |
| Impact Description | In Scotland, native perch populations have declined, and in Russia, whitefish numbers have declined because of egg predation by ruffe (Gymnocephalus cernua). |
| Reference | 1218 |
| Cost | |
| Location | Scotland |