Don’t flush your goldfish, scientists warn

By AG Staff September 19, 2017
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Goldfish have been found invading Australian estuaries and now scientists are cautioning those who may consider flushing their unwanted goldfish down the toilet.

WHILE GOLDFISH are a common pet in Australian households, out in the wild they’re considered pests, and now scientists have discovered they can tolerate salty water, making it easier for them to move between river systems. 

Scientists from Murdoch University made the discovery during recent fish surveys in the Vasse and Wonnerup estuaries in south-west Western Australia. They say this is the first time that goldfish have been recorded in the Wonnerup Estuary.

The new findings mean that it will be more difficult to control the invasive species, said to be capable of growing up to the size of a football.

“The invasive goldfish are vigorous feeders, uprooting and consuming vegetation, silting up waterways and releasing harmful nutrients into the water,” Head Researcher, James Tweedley explained.

The goldfish may even begin using estuaries as ‘saltbridges’ to invade and colonise new river systems.

“Goldfish have been recorded in estuaries elsewhere around the world, but they have been confined to the uppermost parts of those systems or their presence has coincided with periods of high freshwater flows associated with heavy rains.

“However, we discovered the goldfish in the Vasse Estuary in the middle of summer. This is before it becomes very salty, but clearly the fish are capable of tolerating saline conditions for several months,” James said.

Now, scientists are calling on Aussie pet owners to do their part and avoid flushing their goldfish down the toilet. Instead, James is asking that you return unwanted goldfish to reputable aquariums.

“Our waterways are unique, helping to enhance our health and wellbeing, and we should try to do all we can to protect them.”