Michigan’s Feral Giant Goldfish Problem Is Getting Bigger

There are giant goldfish swimming in the waters of Michigan's Great Lakes. Why? Because these fish are tiny in bowls but turn into gigantic ecosystem-draining vacuums in the wild. They may look sweet and docile in their aquarium, but once released into the wild, they wreak havoc on native species and the environment.

Related: Michigan DNR Invasive Species Watchlist: Northern Snakehead

Believe it or not, goldfish were once olive green. However, much like a Chihuahua, which is a direct descendant of wolves, fish breeders took several years of careful planning, and several generations later, they landed on the goldfish we all know today. Despite their pet-like nature in homes, they are devastatingly affecting the areas they populate in the Great Lakes.

When Thinking Michigan Feral Goldfish, Size Matters (But Not How You Think)

Unlike some species, the size of a goldfish isn't determined so much by genetics as by its environment and the amount of food available. So, a goldfish in a bowl will stunt its growth to adapt, but the opposite is also true.

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When Michigan families decide a fish is too much to handle and release it into one of our state's fine lakes, they do more harm than good. These once-small tank fish can grow up to 14 inches on average, with reports of Godzilla-sized ones reaching a whopping 19 inches and 9 pounds once they have access to more than a fish food sprinkle bottle.

Goldfish: The Invaders of Suburban Ponds and Michigan's Lakes

It may be hard to believe, but these pets sold at Meijer have survival skills that would make cockroaches jealous. Goldfish can tolerate extreme temperature swings and lower oxygen concentrations and will eat just about anything that fits in their mouths.

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What's the big deal with a bunch of enormous goldfish residing in Mitten State waters? They are like your teenager's friends who come over after school; they eat everything and leave little for those who live there. Water visibility also suffers due to the goldfish's 'suck and spit' method of feeding on aquatic vegetation.

Alarming Number of Feral Goldfish in Michigan and How to Get Rid of Them

PBS reports the estimated number of feral goldfish living in and upending the Great Lakes ecosystem is in the millions. Removing them is no small feat, either. Minnesota recently held ten events that wiped out only a few hundred. These fish may glitter, but they are anything but gold for Michigan's environment.

Related: The Largest Fish Caught in Michigan: 58 Record Catches

Don't contribute to the chaos. Before you buy a goldfish or give one as a gift, consider whether the recipient will care for the animal or release it into the wild, where it could become a real monster to Michigan's ecosystem.