For several months, rainwater collection ponds in Ottawa, the capital of Canada, have been attacked by goldfish. It is not known exactly how many there are but they have become a problem, so the government says they must eliminate them.
It all started in March after a city councilman received a phone call informing him that there were thousands of dead goldfish in the pond. The number is around 5 thousand and municipal officials have removed them with nets and hands. The fish died due to lack of oxygen in the pond, a common problem in artificial reservoirs.
Now the City of Ottawa says it has discovered a new goldfish population in the same pond. According to preliminary estimates, there will be between 500 and a thousand specimens. Riley Brockington, a city councilor who represents the area, told Canadian public television CBC that the number is huge, and he suspects someone left their pet fish there, although the city officially says it doesn’t know how the fish got into the pond.
Steven Cooke, a biology professor at Carleton University, said even the latest estimates may be wildly imprecise. In fact, goldfish reproduce very quickly: one female can produce up to 6 thousand cubs per year, and therefore one pair is enough for the population to grow very quickly.
Ontario regulations require invasive species caught in these reservoirs to be euthanized. However, goldfish are difficult to catch with nets and the use of chemicals, apart from eliminating all life in the pond, requires a very long approval time. Therefore, according to Cooke, it is likely that problems will occur again and the city will have to intervene again in the coming months.
This is not the first time that goldfish have invaded the lake and it is a problem that arises mainly from the fact that many people who keep them at home as pets, instead of taking them back to the shops, release them into waterways and artificial reservoirs. In these environments, which are often warmer and devoid of predators, carp grow more than usual and become invasive species that can damage local ecosystems: disturbing the seabed, making the water cloudy, stunting plant growth, and competing with native species that are struggling to survive.
– Read also: Scary goldfish
