More models

Species specific water requirements

Flow assessment

Generalised and process models

Carp (Cyprinus carpio)

About Cyprinus carpio

Carp are a large freshwater fish native to central Asia. Carp are very versatile, and can live in a great variety of habitats including highly degraded areas. Over the past few decades carp have spread across most of south-eastern Australia. They are now the most abundant large freshwater fish in some areas, including most of the Murray-Darling Basin, and are thought to have contributed to the degradation of our natural aquatic ecosystems.

Habitat: Carp are usually found in still or slowly flowing waters at low altitudes, especially in areas where there is abundant aquatic vegetation. They are also found in brackish lower reaches of some rivers and coastal lakes.

They are capable of tolerating a range of environmental conditions. They have a greater tolerance of low oxygen levels, pollutants and turbidity than most native fish, and are often associated with degraded habitats, including stagnant waters.

Changes to water flows, declining water quality and other changes to river habitats over the past few decades have negatively affected many native fish while favouring carp.

Reproduction: Under suitable conditions, carp are highly prolific. They mature early – as early as 1 year for males and 2 years for females – and the females produce large numbers of sticky eggs (up to 1.5 million for a 6kg fish).

Carp migrate to and from breeding grounds during the breeding season, sometimes travelling hundreds of kilometres.

Most eggs and larvae die before they reach adulthood, although more may survive if environmental conditions are suitable. Floods seem to provide especially favourable conditions for carp breeding as well as abundant food for juveniles.

Water Requirements

Introduced European carp (C. carpio) spawn in vegetated floodplain wetlands following inundation when water temp is > 16 oC. C. carpio recruits can return to the main stream channel if the floodplain wetlands become reconnected after a spawning event but before the drying of the wetland.

This model uses a flow or depth time series along with a user defined overbank threshold to identify floodplain inundation events. Those inundation events provide adult C. carpio with an opportunity to move from main river channels onto floodplains and spawn. The floodplain wetlands are considered to be filled if an inundation event occurs. If the temperature is suitable when the wetland fills (or at some subsequent time when the wetland still has water) then C. carpio are considered to spawn. C.Carpio recruits are considered to be mature enough to return to the main channel after a user defined period from the commencement of spawning (default 30 days). Hence if a floodplain inundation event occurs when conditions are suitable for viable recruits then the model output records each day when recruitment of C.carpio from the wetlands to the main channel is possible.

Model purpose

The purpose of the model is to analyses long times series of modelled flow to determine if the frequency, duration and timing of over bank flows which fill floodplain wetlands allowing C. carpio to spawn and for recruits to subsequently enter the main river channel is increased by proposed water resource development (represented in the modelled flow).

Development context

This model, describing floodplain connectivity requirements for C. carpio, has been developed using quantitative information from the literature and expert opinion.

It was developed to support the Queensland Department of Environment and Resource Management’s ecological risk assessment for Water Resource Plan (WRP) reviews.

Spatial application

This model and its default parameters were created for application in the Condamine River, Queensland.

However, the model parameters could be edited to suit other locations where C. carpio, occurs or to apply it for other species with similar requirements.

Model description

Ecohydrological rules

Suitable conditions are defined when

  • Temperature > 16°C or seasonal dates that define suitable time of year for carp to spawn (default date season December – May)
  • Minimum duration of connectivity event to allow for effective carp movement following spawning (default 30 days)
  • The time it takes for wetland connections from high flows to subside (drying period – default 30 days)

Assessment methods

This model produces binary daily results (daily recruitment success). These results are then aggregated to a yearly result, and then further to a temporal result based on the defined assessment parameters.

The temporal results are then analysed across locations to report an overall landscape risk by considering the simultaneous occurrence of failures across the system.


  • Daily flow data
  • Daily temperature data (optional)
Parameter Sections
  • Season – The season in which recruitment can occur. Either a set date period, or when the 7 day moving average temperature exceeds a provided threshold.
  • Spawning conditions – define the parameters require to score recruitment. This includes a flow threshold (alternatively the ARI flow can be used), recruitment period and drying time.


  • Daily time series of recruitment success conditions, a score of 1 applies for periods when recruits may return to the main channel and a score of zero when no movement is possible. Additional intermediate results are also provided, including if the day is in season, if the flow threshold was exceeded, if the drying time was not exceeded, if the recruitment days was exceeded and if the final day flow threshold was exceeded.

User interface

Underlying code

This plugin is written in Python and its underlying code is publicly available from the Eco Risk Projector computation repository.


Moffatt, DB & Voller, J 2002, Fish and fish habitat of the Queensland Murray-Darling Basin.Queensland Department of Primary Industries, Brisbane.

Koehn, JD2004, ‘Carp (Cyprinus carpio) as a powerful invader in Australian waterways’,Freshwater Biology, vol. 49, pp.882–894.

Haynes, GD 2009, Population Genetics of Common Carp (Cyprinus carpio L.) in the Murray-Darling Basin,Ph. D. Thesis, University of Sydney.

Gilligan,D & Rayner,T 2007, The distribution, spread, ecological impacts and potential control of carp in the upper Murray River, Fisheries Research Report Series no. 14, NSW Department of Primary Industries, Sydney.

Driver, PD, Harris, JH, Closs, GP & Koen, TB 2005,‘Effects of flow regulation on carp (Cyprinus carpio L.) recruitment in the Murray-Darling basin, Australia’, River Research and Applications, vol. 21, pp. 327–335.

DSITIA 2013. Review of Water Resource (Warrego, Paroo, Bulloo and Nebine) Plan 2003. Review of Water Resource (Warrego, Paroo, Bulloo and Nebine) Plan 2003 and Resource Operations Plan: Environmental risk assessment for selected ecological assets. Department of Science, Information Technology, Innovation and the Arts, Brisbane.

Bennett, L 2008, Inferring the spawning and dispersal behaviour of the common carp, Cyprinuscarpio L., in the Moonie River,Honours Thesis, The University of Queensland.