Pet goldfish may pose a “triple threat” to native biodiversity and releasing them could lead to “catastrophic outcomes”, a new study from the North has shown.
The study, led by James Dickey from the School of Biological Sciences at Queen’s University Belfast, looked at the potential threat of pet fish to the ecosystem.
According to the report, invasive species are known to be one of the leading causes of global biodiversity loss, and the pet trade is responsible for about a third of all aquatic invasive species.
One of the ways this can occur is by pet owners releasing their unwanted fish into the wild, often in a misguided attempt to save the life of the animal.
To better understand this, Mr Dickey and his fellow researchers focused on the two most commonly traded fish species in Northern Ireland: goldfish and the white cloud mountain minnow.
To do this, they developed a new method for assessing the ecological impacts and risks of potential pet trade invaders, based on availability, feeding rates, and behaviour. Through this, they showed goldfish consumed much more than the white cloud mountain minnow or native species.
In terms of behaviour patterns, goldfish were also found to be much braver, a trait linked with invasive spread.
“Our research suggests that goldfish pose a triple threat. Not only are they readily available, but they combine insatiable appetites with bold behaviour,” Mr Dickey said.
The research also found that while northern-European climates are often a barrier to non-native species surviving in the wild, goldfish are known to survive in such conditions and could pose a real threat to native biodiversity in rivers and lakes, eating up the resources that native species depend on.
“Our research highlights that goldfish are high risk, but we hope that the methods developed here can be used to assess others in the pet trade across Ireland and further afield. Readily available species are most likely to be released, so limiting the availability of potentially impactful ones, alongside better education of pet owners, is a solution to preventing damaging invaders establishing in the future,” Mr Dickey added.