Murray-Darling Basin Environmental Water Knowledge and Research Project: Fish Theme Research Report

The MDB EWKR Fish Theme focussed on fish recruitment and sought to improve our understanding of the key drivers, functional processes and limitations of successful recruitment of native fish. This would lead to an improved capacity to predict fish recruitment outcomes in response to different environmental water parameters. In summary, our research demonstrates that both fish population processes, and the key drivers that support recruitment operate at multiple spatial scales, from the patch to the basin scale. Food production areas coupled with appropriate temperature regimes, and the ability for larval dispersal or retention at patch to segment scales, were found to be important drivers of recruitment success. Hydraulic diversity is integral to providing appropriate conditions for food production and dispersal/retention of early-life stages. Connectivity at small to large scales is also critical in enabling access to appropriate habits and dispersal to maintain populations at catchment to basin scales. Our research also demonstrated that under drought
conditions, additional factors such as abundance and condition of adults, and maintenance of refuge areas are likely to be playing a critical role in determining recruitment success.