Yes, Indiana has had giant goldfish and they can be harmful – IndyStar

Invasive species expert tells why we should care about the battle between the species

Destruction from the invasive, leaf-eating gypsy moth caterpillar is plain to see. Yet many more invasive species, though not as prominent, are also on the prowl.

Julie Sherwood, MPNnow

Last week, a football-sized goldfishfound in a Minnesotalake shocked the internet with its size and breadth. In a widely shared Facebook post, the city of Burnsville warned residents not to release their pet fish into public waters, saying "they grow bigger than you think."

But these massive beasts aren't just inMinnesota. Indiana has them, too.

Yes, Indiana has giant goldfish. They're 100% real and not the result of some lab experiment.

But these gargantuan goldfish pose problems beyond their size, as they are an invasive species when found in ponds, lakes or reservoirs.

Large goldfish result from people dumping their fish into bodies of waterand survive when there are not a lot of native fish to prey on them, said Eric Fischer, aquatic invasive species coordinator for the Indiana Division of Fish and Wildlife.However, these huge fish don't pop up very often.

"It's not uncommon, they pop up from time to time, but for the most part, we use them asa good example of why people shouldn't dump aquarium species because of the example of how ... in rare cases, of how they can thrive in Indiana waters," Fischer said.

Don't do it:Why Indiana DNR is reminding people not to dump goldfish in ponds or lakes

Several years ago, at J. Edward Roush Lake in Huntington, officials found 31 goldfish ranging from 6-11 inches.This was likely because "Roush has a problem with not enough native predators," Fischer said.

"In the right conditions, if you stock goldfish into a pond and there's not enough native predators and there's too many undesirable or problematic species like shad or other common carp, those sorts of things, then they can become abundant,"Fischer said."They can reproduce;they can stir up the sediment. They can even cause the native fish to be crowded out. So you have less productivity, and your water quality can diminish."

Goldfish have the capability to grow alongside their environment. If you put a goldfish in a bigger tank, it could grow bigger than what many people consider itstypical size to be.

"They have the capability of getting well up into several pounds. I think I've even seen a goldfish up to about 16inches," Fischer said.

While goldfish are often eaten by native fish, because they're gold, they can pose a threat and become an invasive specieswhen there aren't enough predators to take them down.

But the threat of giant goldfish is just one of an array of problems that can come with dumping out an aquarium into a public body of water, Fischer said.

"When people dump aquariums, they can introduce diseases, they can introduce aquarium plants that can thrive and change the habitat of the lake they're put in, or other fish," Fischer said.

If you can't take care of your fish anymore, there are options for humane fish euthanasia, Fischer said.There are also resources available to fish owners looking to give their fish away.

"A lot of aquarium clubs and mom-and-pop type pet storeswill even take back a lot of fish species and pets ... And they can either rehome them or make sure that they don't get dumped into public waters."

So, what's the moral of the story? Don't dump your goldfish in the lake, lest they become massive and an invasive species.

"What I want people to know is they shouldn't be dumping aquariums and they shouldn't be introducing things because they can introduce species that can become invasive," Fischer said.

Contact IndyStar Pulliam Fellow Claire Rafford at crafford@gannett.com or on Twitter @clairerafford

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Yes, Indiana has had giant goldfish and they can be harmful - IndyStar