Ottawa officials to cull mindblowing' influx of thousands of goldfish in pond

"The fact that we've had approximately 6,000 fish in this pond, in this year, is mind-blowing, councillor Riley Brockington, who represents the area, told CBC News. It's just a number that's difficult for me to wrap my head around. Female goldfish produce large amounts of offspring, with a single mature fish able to lay more than 100,000 eggs. Carleton biology professor Steven Cooke told the national broadcaster the actual population of the Celebration Park shoal could far exceed official estimates, speculating that there could be millions of tiny young goldfish in the pond, undetected."

"The scourge of goldfish a species native to Asia and most commonly found in fish tanks has become a growing problem as the fish are deliberately released by pet owners into increasingly warm waters. Goldfish can grow to immense sizes in large bodies of water, have few predators and reproduce rapidly. They displacing native species and harm plant growth by churning up waters of ponds."

"Warming water temperatures from a changing climate have also created a more hospitable environments for the populations as they spread through local waterways and into the Great Lakes. Authorities in the Canada and the US have pleaded with aquarium owners to stop releasing pet fish into waterways. In Minnesota, officials removed nearly 50,000 goldfish from local waters. They warned that fish which might be only two or three inches long when they are released can grow to more than 1ft long."

Thousands of feral goldfish have infested an Ottawa stormwater pond, with city staff removing 5,000 earlier this year and an estimated 1,000 remaining. Female goldfish can lay more than 100,000 eggs, and biologists warn that millions of undetected young could be present. Goldfish, native to Asia and commonly kept as pets, are deliberately released into warming waters where they grow large, face few predators, reproduce rapidly, displace native species, and damage plant growth by churning sediments. Climate-driven warmer temperatures enable further expansion through local waterways and into the Great Lakes, prompting culls and public pleas to stop releases.

Read at www.theguardian.com