July 13 (UPI) -- Officials in a Minnesota city are asking residents not to dump their unwanted goldfish after a local lake was found to be home to goldfish up to 18 inches long.
The city of Burnsville shared photos of some massive goldfish removed from Keller Lake during a recent survey.
"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," the city tweeted.
The city said 10 fish, measuring up to a foot long, were found during the survey. Officials said a second survey conducted Monday resulted in finding 18 more goldfish, with the largest measuring 18 inches long and weighing in at 4 pounds.
"Most of them were definitely bigger than you'd find in your typical aquarium," Daryl Jacobson, the city's natural resources manager, told the Minneapolis Star-Tribune.
Jacobson said goldfish released into lakes compete with native species for food and encourage algae growth. He said the fish are likely also living in other nearby bodies of water.
"Goldfish are a pretty hardy species," he said.