Impacts of managed flows on fish spawning and recruitment: Scoping Study for Project R5002

"March 2006".

Project Number: Impacts of managed flows on fish spawning and recruitment - M/BUS/84.

MDFRC item.

This scoping study was undertaken to provide essential background for a Murray–Darling Freshwater Research Centre (MDFRC) project entitled, 'Impact of managed flows on fish spawning and recruitment'. The aim of this project is to investigate the links between altered flows, the timing of fish spawning, and the levels of subsequent juvenile recruitment into riverine fish populations, across the Murray–Darling Basin. To achieve this, several hypotheses are to be tested, regarding the ways in which flow alteration may influence the recruitment dynamics of native and alien fish species, which have different durations of spawning. The main objectives of the scoping study were to: 1) Review briefly the available scientific literature on recruitment and spawning in freshwater fishes. 2) Further develop conceptual and predictive models of fish recruitment timing and 'success' in lowland rivers. 3) Scope the future of flow management in selected rivers for the main study, in conjunction with appropriate water agencies within each study region. 4) Further develop appropriate hypotheses, indicators and suggested sampling designs for the project's second phase.