Pet goldfish released into the wild can cause major problems

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goldfish "gotta go get food" gifFor pretty much every three goldfish we here at buy from the pet store, one lives a long life and the other die of unknown causes fairly early on no matter how careful we are with water quality, food, etc. So we always thought of them as fairly fragile and were surprised to learn that dumped goldfish reproducing in the wild is a problem.

But, apparently it is. A big one!

According to an article published in the Business Insider in April, thousands of goldfish “invaded” West Medical Lake in Washington, leaving the Department of Fish and Wildlife to suspect a few irresponsible pet owners.

When most people think of animals released into the wild, snakes and iguanas in Florida come to mind, but there are other animals that are commonly ditched as well and it wreaks havoc on the animals and the environment.

But, although they make low-key and picturesque pets, goldfish can wreak havoc with the best of them, bring “wow, my pet did THAT!?” to a whole new level.

goldfish swimming
While goldfish are beautiful to watch in tanks, they have been known to cause damage when left to their own devices in the wild.

According to an article from The New York Times, someone dropped some goldfish in a creek in Australia 20 years ago. They traveled, spawned and took over a whole river. And, in Australia’s Vasse River, some goldfish, probably similarly ancestors of other discarded pets, grow up to 16 inches in length.

According to, goldfish eat crustaceans, insects, and plant matter. They are “opportunistic feeders,” meaning they don’t stop eating while there is food around. The ability to gobble up the food supply that other fish depend on and also the fact that they produce more waste when they overeat, thus polluting the water, is a large part of why they become problematic.

An article in the Washington Post also sites the introduction of diseases by goldfish as another negative effect.

Nevada, Colorado are some other states that have had issues with goldfish in the wild and Canada and the United Kingdom are among other affected countries.

The takeaway is, for those who can’t keep their fish anymore, it’s best to find a friend or another person who will give it a home. Unlike some types of pets, fish are typically easy to re-home. Posting on Facebook, Twitter and through social media can be effective. As can offering to donate your tank and fish to a classroom at a local school, daycare center, waiting room at a doctor’s office or a church daycare center. Or try a pet adoption website. has a fish section for those looking to adopt or give up a goldfish, among other types of pets.



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