Previous research into carp control
Over the past few decades, research on carp biology, impacts, and control tools and strategies has primarily been undertaken and coordinated by the Invasive Animals Cooperative Research Centre, and the preceding Pest Animal Control Cooperative Research Centre.
There's a range of options for controlling carp that people have been trying for years. This includes things like traps, nets, electrofishing, angling, genetic engineering and chemicals. Some methods catch lots of fish with little specificity; others catch fewer fish, but are more targeted. Unfortunately, most only work in small areas – there hasn't been a feasible way to tackle carp at a large scale.
A team from the Arthur Rylah Institute used electrofishing to remove carp downstream from Yarrawonga Weir, May 2017. Images: Tom Rayner.
Meanwhile, work on carp herpesvirus has progressed. In 2006, CSIRO’s Australian Animal Health Laboratory began assessing its potential as a carp biocontrol agent. This work involved testing a series of native Australian fishes, rainbow trout and model species of reptiles, crustaceans, amphibians, birds and mammals for susceptibility to disease caused by carp herpesvirus (McColl et al., 2016).
The results shows carp herpesvirus is a potentially-viable and effective biological control agent for carp in Australia. It is species-specific and could control carp across their range. However, as with previous viral biocontrol agents (e.g., rabbits), optimal carp population reductions would be obtained by deploying the carp virus in conjunction with other control measures (McColl et al., 2016a), including a sex-biasing construct (e.g., daughterless carp) to eradicate carp in fewer than 10 generations (Thresher et al., 2014).
For the NCCP, this work means we know that long-term reduction of carp impacts will require the use of a suite of control measures. The virus could get us part, or most, of the way in the short to medium term, but additional tools would be required to prevent carp numbers from rebuilding (Thresher et al., 2014). Identifying and refining complimentary methods, in concert with biocontrol, is therefore a priority under the NCCP – as are the practical aspects of actually getting the job done.