While doing routine monitoring, Carver County Water Management staff discovered thousands of goldfish in an inlet to Big Woods Lake in Chaska. The discovery has citizens wondering how they got there, if they are affecting the lake, and if there is anything to be done. It’s not the first time staff have found goldfish in lakes, but this discovery is the most densely populated one.
While its unknown how exactly the fish got there, the most likely explanation is one or more individuals illegally dumped pet goldfish.
Impacts to the lakes
Like many aquarium pets, goldfish are not native to Minnesota. Goldfish are related to and share many of the same bad habits as common carp: stirring up sediments, uprooting plants while feeding, and competing with native fish for food and shelter. An invasive species, goldfish can reproduce rapidly and are pretty hardy. They can even survive the low oxygen conditions in winter. They can live up to 25 years old.
What to do
Once established, no easy solution exists to remove an invasive species like goldfish. Big Woods Lake is part of the Grace Chain of Lakes, which includes five connected lakes. To be most effective with management, a project would need to target all five lakes. Our organization is looking at methods to address the water quality issues in the chain of lakes, and some of these strategies would also address the goldfish. The methods being considered require broader engineering, planning, and funding.
The best immediate action is to continue to increase awareness that releasing pets can impacts lakes, rivers and wildlife, and that they are better options.
What if you no longer want or can care for a pet?
If you have a pet you no longer want or can’t care for, the appropriate thing to do is find it a new home. Donate it or take it to a surrender event. Surrender events are usually free and open to the public. You can bring aquatic animals and plants and the hosting organization will help to find them new homes. The MN Aquarium Society has an upcoming surrender event on April 27th in Bloomington.
You can also check with local veterinarians and pet stores for surrender and new-home opportunities.
Can people come get them?
Minnesota state law prohibits transporting of live fish without the appropriate permit. A fishing license allows an individual to fish for them with hook and line, but you cannot transport them live. A fishing license is not a permit to transport live fish.
Goldfish cannot be used as bait. That is another way they get released into lakes and rivers.
The organization wants to discourage any movement of these fish. They are invasive and moving them increases the risk they could escape into another lake or river.
Fishing for rough fish - Minnesota Dept. of Natural Resources