As you read this, Australia is being invaded by an insidious creature that’s wiping out entire populations and spreading a virulent disease causing the deaths of hundreds of fish.
For the past twelve years, the Centre of Fish and Fisheries at Murdoch University have been trying to get the goldfish population in the Vasse River, Australia, under control.
Despite seeming like a harmless pet, the shiny little fish can have a massive impact on native fish populations and the surrounding ecosystem, Mashable reports.
Goldfish aren’t a natural part of the river’s ecosystem, being a type of domesticated carp from Asia, yet there’s been a huge rise in the number of goldfish along with other aquarium species being found in the Vasse.
Stephen Beatty and his team spent the year studying goldfish in the wild and believe they discovered where the goldfish were coming from.
We think it’s a major factor, people letting their aquarium species go. Unwanted pets, basically. They can do quite a lot of harm.
While they may seem pleasant enough, goldfish are omnivores and they’ll happily destroy vegetation and devour native fish eggs, out-competing local fish for resources.
Worst of all, these aquarium fish have introduced new diseases into the water, further devastating local populations.
The goldfish are now growing to mammoth sizes with one fish weighing 1.9 kilograms.
Beatty and his team are now working on ways to get rid of the fish using nets and electrofishing, but he claims there are difficulties in removing alien species from bodies of water without damaging the local fish population.
The key thing is if you’ve got unwanted pets, you can see if the pet shops will take them back. But if you’re going to euthanise them, putting them in the freezer is the most humane way.
But just letting go of a pet, no matter how innocuous you think it is in your aquarium, or how pretty it is, can potentially cause a lot of damage. Not all fish you let go will form a self-maintaining population, but we’re finding more and more that do.
Who’d have thought a simple goldfish would be one of the most dangerous creatures in Australia?