Unwanted Pet Goldfish Dumped In Lakes Are Growing To Be As Big As Rugby Balls


Unwanted Pet Goldfish Dumped In Lakes Are Growing To Be As Big As Rugby BallsBurnsvilleMN/Twitter

Conservationists in Minnesota have requested that people stop releasing goldfish into lakes as they are now considered an invasive species.

A goldfish may seem like a harmless animal, but it is causing issues for the city of Burnsville, a suburb of Minneapolis. In fact, local conservationists have shown images of goldfish that have been released into lakes that are the size of rugby balls.


On the back of this, the authorities have issued a warning about how to deal with unwanted pet goldfish.

Check out the giant goldfish found in Keller Lake:

The post by the City of Burnsville explains that goldfish grow bigger than many would expect and ‘contribute to poor water quality by mucking up the bottom sediments and uprooting plants’. As strange as this issue may sound, it has been a long-running problem in waters.


Goldfish were considered ‘disposable’ since they began to appear as prizes in fares in the 1800s, New York Times reports. On the back of this outlook, many have released their prizes without considering the environmental impact it may have. Goldfish can also be used as bait by fishermen and this is believed to have added to the issue.

In 2020, 30,000 to 50,000 abandoned goldfish were removed from the waters in the nearby Carver County, Minnesota.

In this instance, the county explained:

An invasive species, goldfish can reproduce rapidly and are hardy, surviving the low oxygen conditions in winter. They can live to be 25 years old, and once established, no easy solution exists to remove an invasive species like goldfish.

Goldfish (PA)PA Images

In fact, the US Fish and Wildlife Service has discussed the expense required to help wildlife impacted by invasive species. The organisation states that every year invasive species lead to ‘$120 billion in damages to our country’. Not only that, but there are ‘billions of additional dollars are spent on prevention, detection, control, management, outreach and habitat restoration’.

Caleb Ashling, a natural resources specialist, explained the current situation to The Washington Post:

Goldfish have the ability to drastically change water quality, which can have a cascade of impacts on plants and other animals.

People are trying to be nice, but they don’t realise that goldfish can have a lot of unintended consequences. Most people really care about their lakes and ponds, but you may be causing problems you weren’t aware of if you let them go there.


This issue is not specific to the Minneapolis area and has also impacted counties like Canada and Australia.

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Topics: Animals, Minneapolis, Now, US


The Washington Post and 3 others
  1. The Washington Post

    People dumped their pets into lakes, officials say. Now football-size goldfish are taking over.

  2. US Fish and Wildlife Service

    How to break up with your goldfish

  3. Carver County Minnesota

    Goldfish Removal Project in Grace Chain of Lakes

  4. The New York Times

    In the Wild, Goldfish Turn From Pet to Pest

Daniel Richardson
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