Ginormous goldfish are invading Australian rivers
Ginormous goldfish are invading Australian rivers A man holds one of the giant goldfish. (Murdoch University/AP Photo/Martin Mejia)
Ginormous goldfish are invading Australian rivers
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There's nothing cuter than a goldfish. They are small, bright and distinctly cheerful-looking. They're a staple of fish tanks around the world. But Australian scientists are not so enamored with the little darlings, reports Johnny Lieu for Mashable. Not only are they invading Australian rivers, but they're also growing to gargantuan sizes.
The huge goldfish of Western Australia are anything but adorable. Over the last 15 years, Lieu reports, they've taken to freshwater rivers in ever-greater number along with a host of other aquarium fish. A new study has been published in the journal Ecology of Freshwater Fish. Researchers reveal how the fish have spread throughout Australian waterways. The fish have grown ever larger as they go.
The fish are not just big, the study found, they're incredibly mobile. In just five days, they can travel an average of one mile in the river. One fish went a whopping 3.35 miles in a mere 24 hours.
Over a year-long period, researchers tracked the movements of goldfish in the lower Vasse River. The researchers used acoustic testing and tagging to determine what fish were doing. The goldfish that were studied didn't just swim around. They appear to have spawned. Ecologists call it "spawning migration," a pattern in which fish breed in areas far away from their normal hangouts.

That's bad news. This is according to Stephen Beatty. He is a senior research fellow at Murdoch University's Centre for Fish & Fisheries Research, who led the study. He spoke with
"The fact that they're so big is really symptomatic of the other impacts in the river," Beatty says. The river, he explains, is warm and stagnant. Those are perfect conditions for pet goldfish, who make their way into waterways after being released by their owners.
"The goldfish have really capitalized on that," he says. Not only do the goldfish disturb the habitat and potentially consume invertebrates and fish eggs, his team suspects that they are also disease vectors.
Carassius auratus originated in Asia. That is the scientific name for goldfish. They are kept as pets the world over. But when they're released into the wild, the well-behaved fish tank friend becomes a foe to other wildlife. Not only do they grow without the constraints of a tank and commercial fish food, but their feeding frenzy also causes mud and debris to rise from the bottom of the river. That fuels the growth of aquatic plants, which can degrade the river even further.
And while splashing around in the warm, nutrient-rich environment they love, they breed like crazy.
It's become an issue throughout the world.  A Boulder, Colorado, lake teems with the fish and in Alberta, Canada, the problem has become so bad that officials pleaded with the public not to release them.
For Beatty, all that press is a good thing: "They're a bit of a flagship because they do get that media attention," he concedes. But their star status has a downside - a misconception that if your goldfish is tiny, it won't hurt to drop it in a lake or river.
"Introduced species can have really unpredictable impacts, even cute and fuzzy ones," he says. "Please don't release anything into rivers or wetlands that are not native there."

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How do the goldfish interfere with the existing habitat?
Write your answers in the comments section below

  • andriannar1-bla
    9/15/2016 - 08:36 a.m.

    The goldfish interferes that the other habitat because they are multiplying fast and eating fish eggs and other of fishes things. These goldfish are also destroying other environment around them.

  • samr-bla
    9/15/2016 - 08:37 a.m.

    I think goldfish interfere with wildlife because the article says that goldfish are a foe to wildlife. Gold fish feeding frenzy that cause mud and debris to rise up in the river.

  • ashleighs-bla
    9/15/2016 - 09:32 a.m.

    These goldfish, when the are released they breed so much that it is crowding the rivers and lakes. What is also bad about them spawning so much is that they may carry diseases. When they eat the debris and mud float up to the top of the water. The mud and debris help the aquatic plant in the rivers and lake even more which means that the rivers get even more crowded. I think that that is really bad because it makes the rivers look bad and and it destroyes the rivers for the animals that eat regular fish from that river. they will eventually have to find a different river somewhere else.

  • andrewb-pav
    9/15/2016 - 09:59 a.m.

    The goldfish are becoming a real problem towards all the life in the river killing other fish and there eggs

  • lizm-pav
    9/15/2016 - 10:01 a.m.

    Although these fish may be cool and unique, they are deadly. Scientists need to find a way to stop the deadly disease these fish can cause.

  • kirstenw-pav
    9/15/2016 - 10:02 a.m.

    These goldfish are carrying diseases and since there are so many fish swimming up and down these rivers, it might get worse.

  • jackies-pav
    9/15/2016 - 10:04 a.m.

    I think that the size of the goldfish is really cool, but if they are endangering the habitat and the next generation of fish, then I guess that even though they're cute, the goldfish aren't doing anything good.

  • carolinec-pav
    9/15/2016 - 10:04 a.m.

    In my opinion, I think the goldfish are very cute. They may be growing insanely large but they are not physically harming other species in the river.

  • nataliak-pav
    9/15/2016 - 10:04 a.m.

    At one point in time everyone has wanted a pet fish. Although pet owners wan the very best for their fish, releasing them into the wild is not beneficial for themselves or the environment. As the story has stated these fish go on feeding frenzy's and end up eating all of the food and destroying rivers.

  • haydenb-bla
    9/15/2016 - 10:18 a.m.

    This article is really cool because I never knew a house hold pet that a lot of people have, around the world, is destroying the habitat of many other marine animals. The size of the fish is also crazy, I never knew a small fish that you get in a bag from a relative, the fair, or a store, could grow big enough to eat other organisms.

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