The image shows just how widespread the pests have become -- and how seriously recreational fishers are taking the issue.
It's no secret that Australian waterways are under threat from invasive species, with European carp frequently named as one of the country's worst invaders, causing unprecedented levels of damage across the nation's fragile ecosystems.
Recently, calls have surged for intervention from the federal government, amid reports that the pests now make up an astonishing 90 per cent of fish biomass in waterways like the Murray-Darling Basin. And while many experts agree that large-scale efforts are necessary, the public can also play a role.
This week, a photo showing dozens of carp piled in the back of a ute went viral online, sparking renewed interest in the fight against the destructive species. The image, taken by the NSW Fishing Clubs Association (NSWFCA) last year, and recirculated on Tuesday, shows just how widespread the pests have become -- and how seriously recreational fishers are taking the issue.
Speaking to Yahoo News, NSWFCA Secretary Craig McCartney explained that the photo was taken by his brother Daniel during the Freshwater Titles at Wyangala Dam, on the junction of the Lachlan and Abercrombie rivers, last October. It's an annual fishing competition where anglers target pest species like carp as part of broader management efforts.
He shed some light on why it's struck a chord again, as the problem worsens across Australia's inland waterways. "Fifty anglers were competing that weekend, and most presented their bag limit of five carp to the scales for weighing," he said, of the 700kg haul.
"The bag limit is imposed [because without it], there could have been thousands of fish captured, but that would be very hard to manage in terms of weighing and disposing of fish."
In the photo, countless carp can be seen piled on top of one another, highlighting the massive effort by participants on the day. "As you can see, there were a lot of fish caught, primarily the pictured noxious species, carp," Craig said.
The largest fish caught, Craig recalled, weighed an incredible 7.06kg and was 95 centimetres in length. He said the event is hosted every year, with the next taking place later this month, on October 25 and 26 at the Wyangala Waters Holiday Park.
"This event has been going on for many years, several decades," he said. "The NSWFCA, along with many other fishing groups, have been removing carp from NSW waterways for a long time."
Across the country, carp are considered a noxious aquatic pest, and they cannot be returned to the water alive or kept without a permit. In the Murray-Darling Basin -- which flows through Queensland, NSW, Victoria, South Australia and the ACT -- carp are thought to make up to 90 per cent of fish biomass.
They were first introduced in the mid-1800s as ornamental fish in private ponds. But in the 1960s, when a genetic line called the "Boolara strain" was released into Victorian waters, carp quickly spread throughout the eastern and southern states.
Their impact is severe because they feed by sucking and disturbing sediments at the bottom of rivers and lakes. This behaviour muddies the water, uproots plants, reduces water clarity, and releases nutrients that fuel algal blooms.
Native fish and aquatic plants struggle to survive in these degraded conditions, while carp thrive. The result is poorer water quality, damaged ecosystems, and fewer habitats for native species.