FRDC is leading a National Carp Control Plan (NCCP) to ensure maximum success of the CyHV-3 virus. The objective of the present proposal is to inform resource allocation for CyHV-3 release planning, clean-up and management of potential ecological impacts, and provide a robust estimate of carp abundance and biomass in a broad range of aquatic habitats, reaches and river basins in eastern Australia. As part of this program it is underrating an assessment of Carp biomasses (NCCP: Preparing for carp herpesvirus: a carp biomass estimate for eastern Australia) based on data collected at various points in time.

Carp are highly fecund and adaptable and therefore their populations are extremely dynamic. This means that any static population estimate at any particular point in time can quickly change, and therefore must be used cautiously. It also means that overall populations can vary widely: data from river surveys in the mid-Murray (relatively stable habitats) varied by about 200% pre-, during and post drought. Less stable habitats would be likely to have higher levels of population variability. By their very nature, population assessments can only be undertaken at individual sites at particular points in time and there is the need for adjustments to this data to provide more accurate estimates of populations for any other point in time.
Carp population dynamics are driven by very large recruitment events and there are three factors that influence recruitment events:
1. flows (hydrology); and
2. access to habitats (often also dictated by flows)
3. existing population structure
Carp populations are particularly responsive to conditions conducive to recruitment, especially when there are successive events that cumulatively drive populations. Therefore, these aspects need to be taken into account to guide management and allow predictions to be made as to actions and likely outcomes. The carp biomass estimate currently being undertaken will give a point-in-time estimate for July 2018. This will need to be adjusted for any release date beyond 2018. Data collected should allow for examination of the existing population structure, which can then be added into the model for future predictions.