Goldfish
Invasive SpeciesFound in 13 lakes
Goldfish is documented in 13 lakes across our dataset — 10 in Minnesota, 2 in Missouri, and 1 in Wisconsin. Each state's natural-resources agency maintains an official "infested waters" roster that triggers boat-launch decontamination protocols. 13 lakes — narrow enough that aggressive containment is still on the table. Most upper-Midwest invasives that established here did so quietly over a decade before anyone noticed, so a low number today is not a guarantee for tomorrow.
The presence of Goldfish does not directly change a lake's LakeGrade rubric score — the grade measures the water itself, not the species inhabiting it. But invasive presence is a meaningful adjacent signal worth reading alongside the grade.
Lakes with Goldfish
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Rock Lake | Jefferson | WI | B | 60 ft |
| Bde Maka Ska Lake | Hennepin | MN | C | 82 ft |
| Harriet Lake | Hennepin | MN | C | 87 ft |
| Loeb Lake | Ramsey | MN | C | 28 ft |
| Clearwater Lake | Reynolds | MO | C | - |
| Clearwater Lake | Reynolds | MO | C | - |
| Cedar Lake | Hennepin | MN | D | 51 ft |
| Silver Lake | Hennepin | MN | D | - |
| Lucy Lake | Carver | MN | D | 20 ft |
| Lake of the Isles | Hennepin | MN | D | 31 ft |
| Brownie Lake | Hennepin | MN | D | 47 ft |
| Wolfe Park Lake | Hennepin | MN | D | 25 ft |
| Como Lake | Ramsey | MN | F | 15.5 ft |
Frequently Asked Questions
How many lakes have goldfish?
Goldfish has been documented in 13 graded lakes: 10 in Minnesota, 2 in Missouri, 1 in Wisconsin.
Does goldfish affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with goldfish should be monitored for changes in water quality over time.
Invasives Found With Goldfish
Source: EPA National Aquatic Resource Surveys, 2026.