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Goldfish owners warned not to put them in ponds or lakes

goldfish
(Image credit: Getty Images)

There’s a good chance that you may have released a pet goldfish into a pond or lake, for whatever reason.

Seems a pretty harmless action, right? Wrong. As this case study shows, releasing goldfish into a natural body of water can have serious consequences for the balance of the local ecosystem.

A somewhat humorous illustration of what can happen has been shown in this tweet from the official Twitter account for the city of Burnsville, Minnesota, which shows released pet goldfish having grown to truly gigantic proportions.

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Typically, goldfish in a tank grow to a length of about 2 inches (5.1cm). However, as you can see from the picture, they can greatly exceed that when left to their own devices in the wild.

As the tweet says, goldfish can disturb the sediment and uproot plants. Moreover, the rate at which they breed and consume food means that they quickly become the dominant species in the ecosystem, with potentially dire repercussions for the other species present there.

There have been numerous examples of this happening worldwide, with the BBC (opens in new tab) reporting that over 50,000 goldfish had been removed from just one creek in nearby Carver Creek.

So the message to come out of this is pretty simple: even if you have just the one goldfish, do not under any circumstances release it in a nearby lake or pond. 

There are plenty of great fish tanks to choose from, as you can see in our guide to the best fish tank.

Alternatively, if you decide that goldfish aren’t for you, why not choose a different type? For more information, read our guide on how to choose the right pet fish.

Whatever you do, please aware of what your decisions have on the local wildlife. There are many more solutions to bear in mind before resorting to dumping your goldfish in an environment that they’re not suited to.

Steve writes and proofreads buying guides, news stories and advice for Pets Radar, drawing on his lifelong experience as a pet owner. Currently sharing his house with two cats and a dog, he draws on the many highs and occasional lows of pet ownership he has borne witness to in his writing. He has worked in publishing for 15 years as an editor, sub editor and writer on a range of titles, such as SciFiNow, How It Works, All About History, Real Crime and Horrorville. You can follow him on Twitter @stevewright22