The National Carp Control Plan (NCCP), operating within the Fisheries Research and Development Corporation (FRDC), is developing a plan for the potential release of the virus known as Cyprinid herpesvirus 3 (CyHVto control invasive common carp, Cyprinus carpio, in Australian freshwater environments.
If the carp virus is approved for release, major carp mortality events are likely and the degradation of carp carcasses is likely to release a considerable amount of nutrients into the water column. Given the enormous biomass of carp in the Murray Darling Basin it is unlikely that this biomass will all be removed in a ‘clean-up’. Consequently, a strategy will be required to ensure this increase in nutrients does not become problematic. Of particular concern is ensuring that these nutrients do not fuel cyanobacterial blooms, which can compromise water quality by the production of toxins, and compounds that taint the taste and odour of water.

Preliminary work has been carried out at the University of Adelaide measuring the remobilisation rate of phosphorus from decaying carp tissue. This work needs to be expanded and incorporated into prediction of phytoplankton growth in the Murray Darling System to determine how this will support algal growth. Nutrients will interact with flow to determine phytoplankton abundance, species dominance and succession. The bloom forming cyanobacteria in the Murray Darling Basin tend to dominate under warm, stable stratified conditions. Consequently flow can be used as a strategy to ensure mixed conditions in the rivers and a greater likelihood that nutrients will be directed into phytoplankton species other than cyanobacteria.