| Impact ID | 4570 |
| Impact Type | Habitat Alteration |
| Study Type | Observational |
| Study Location | Field |
| Impact Description | the normal underwater 'forest like' structure which provides refuge, shelter and nursery space for minnows and warm-water fishes is being replaced by thick aggregations |
| Reference | 36862 |
| Great Lakes Region | Yes |
| Cost | |
| Location | Lake Simcoe |