NCCP: Risks, costs, and water industry response
To date, only a few of experiments have been conducted on the impact of rotting carp on water quality and none of these has extended as far as investigating impacts on water treatment. A few experiments have been conducted as part of the NCCP research program, with a focus on dissolved oxygen and phosphorus dynamics. These experiments have been conducted in buckets (~5L), experimental ponds (~200L) and mesocosms within wetlands (~500L) and have incubated various densities of dead carp (however not CyHV-3 killed) and investigated the impacts on various water quality variables (Laws et al., 2016). These experiments have revealed the potential for the mass mortality of carp to cause hypoxia and anoxia in parts of the River Murray, especially associated with high biomass and shallow water. Therefore, significant ecological risks exist in back waters and wetlands. Modelling of the main river channel suggested that the main channel would not become anoxic; however this is predicated on the assumption of homogenous carp density. As carp display aggregation and schooling behaviour and following death may be concentrated by hydrodynamic processes, there may be localised impacts in the main channel.
Experiments conducted by SA Water in ~700L of River Murray water and a range of carp densities have demonstrated the potential for serious impairment of raw water quality. The observed increases in the concentrations of DOC and ammonium were of significant concern from a water treatment and disinfection perspective. Experiments performed by Water NSW and UTS in mesocosms in Prospect Reservoir used carp densities of 250, 500 and 1000 kg ha-1. Their experiments revealed increases in E. coli concentration, as well as large shifts in dissolved oxygen dynamics associated with both heterotrophic decomposition and nutrient impacts on phytoplankton productivity; from this followed increased concentrations of taste and odour compounds.
Final report
NCCP - Engineering Options for the National Carp Control Plan
The project relates to the design, consultation, delivery and reporting of a National Carp Control Plan (NCCP) 'Engineering Options' workshop. The project has been identified as a priority by the Operations Working Group as part of the NCCP and is intended to provide engineering, logistics and contracting knowledge to support high biomass clean up planning and execution.
The proposed workshop will focus on the development and evaluation of options for commercial scale carp clean up and disposal following high biomass carp kills across a wide range of public and private water bodies.
The workshop would be designed and delivered is such a way as compliment the other initiatives that have been, or are being explored by the NCCP, in particular, the recovery and disposal options literature review and the current engagement/investigations underway with the commercial fishing sector.
Final report
behalf of the National Carp Control Program (NCCP), to deliver a project exploring possible engineering
and technology options to address the range of high-biomass clean-up and disposal scenarios associated
with possible deployment of the Cyprinid herpesvirus 3 (CyHV-3, hereafter ‘the carp virus’) as a
biocontrol agent for carp (Cyprinus carpio) in south eastern Australia. The project was identified as a
priority by the NCCP Operations Working Group to provide operational, engineering, logistics and
contracting knowledge to support high biomass clean-up planning and execution.
Strategy through identification of a range of suitable works and measures that will effectively and
efficiently reduce the impact of large scale carp mortality in inland waterways.