They seem so innocent in their bowls on top of dressers or in living room aquariums. But, if they are released into larger bodies of water, goldfish can wreak havoc.

“Please don’t release your pet goldfish into ponds and lakes! They grow bigger than you think and contribute to poor water quality by mucking up the bottom sediments and uprooting plants,” tweeted the City of Burnsville, Minn.

When released into larger bodies of water, goldfish can grow to the size of a football. They can quickly reproduce, overtake native species and destroy the underwater environment. Goldfish can live to be 25 years old, weigh up to four pounds and measure longer than a foot. They can survive in a body of water that is frozen at the top.

Goldfish come from the carp family and feed at the bottoms of lakes where they can disturb plants, kicking up sediment, potentially causing algal blooms, which can negatively impact water quality and harm other native species.

If your time as a goldfish owner has run its course, please do not dump your fish into your local lake or pond. Consider finding a new owner or returning it to the pet store instead.

Photo credit: City of Burnsville