Australian bass spawn in estuaries in winter, generally in the months of July or August. There is uncertainty about the salinity levels that Australian bass spawn in. Estuaries are dynamic habitats with daily fluxes in salinity due to tides, and are also affected by droughts, floods and freshes (minor, temporary rises in flow), making measurements of preferred spawning salinities for wild Australian bass difficult. However, based on capture of recently spawned larval and juvenile Australian bass in estuaries, the species appears to spawn in a salinity range of 8–12 parts per thousand (salt water is approximately 36 ppt). Australian bass sperm have no viability at or below 6 ppt, but are most viable at 12 ppt, the latter probably being the most relevant fact. However, it has been reported that Australian bass spawned in salinities of 12–18 ppt, with this statement based on fishermens' reports of observing wild Australian bass spawnings and some unpublished data gathered by the NSW Fisheries Department.