Though flushing “Goldie” down the toilet or setting it free in a creek may seem an expedient option for an unwanted aquarium pet, it just means they’ll end up in streams and lakes, where they can turn into an ecological pest, according to The Ohio State University.
Goldfish are a non-native and invasive fish species — meaning they’re not supposed to be here, and they can take food away from other native fish, the university’s College of Food, Agricultural and Environmental Sciences reported in 2017.
They’re actually from Asia.
“These invasive goldfish can grow to massive sizes by taking food resources from native species of fish,” the college reported. “They have also been found to eat the eggs of other native fish species even further so hurting their future populations. Goldfish also occupy habitats that native fish use for reproduction as well as shelter and are even able to reproduce with the common carp to produce larger, hybrid species that are equally as detrimental to native populations.”
Improper disposal of dead goldfish can also introduce parasites and other diseases to native fish, according to the college.
We’ve heard these warnings before. Last summer, officials in Minnesota reported finding more giant goldfish in waterways, prompting a plea to citizens to stop illegally dumping their unwanted fish into ponds and lakes.
Goldfish can grow to the size of a football and are able to survive in frozen lakes and those with very poor water quality because they can live without oxygen for long periods.
The Ohio State University, citing NPR fish biologist Ben Swigle, recommends freezing dead goldfish overnight before disposing of them in the trash. For live fish, you might consider taking them back to the pet store, or giving them a new home (in an aquarium, that is).
The Associated Press contributed to this report.