Black bream (Acanthopagrus butcheri) is a commercially and recreationally important species that is prevalent in southern Australia, with Gippsland Lakes being the most important commercial fishery in Victoria. Despite being long-lived, there are typically only a few dominant age classes sustaining the fishery, due to large interannual variability in recruitment. Although black bream spawn daily over a 2-5 month period, the catch numbers in the Gippsland Lakes have been in decline since the mid-1980s. To investigate the sources of variation in recruitment of black bream as well as to determine the spatial distributions of natal cohorts, we sampled juveniles from all accessible seagrass beds throughout Lake King over the autumn months of 2015 and 2016. We extracted sagittal otoliths from caught juveniles and analysed their cores using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). We used the chemical signatures from these analyses to reconstruct natal groups and to provide insight into the relative contribution of tributaries to year class strength and recruitment. Our results will allow for the management of this iconic and essential fishery both in terms of identifying key spawning locations and the drivers of year class strength.