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.