The most significant threat to the Murray hardyhead is the lack of water (4) (6). Increasingly prolonged periods of dry conditions in the Murray-Darling basin have led to many important sites drying up or salinity levels becoming too high (2) (4). The Murray hardyhead is now thought to be extinct in the New South Wales (7) and further population declines are predicted throughout the remaining range (6).
A further threat to this species lies in the reduction of connecting waterways between lakes and the Murray River channel, resulting in the isolation and extinction of local populations (3) (2). The Murray hardyhead relies on such waterways for dispersal and recolonisation of new habitats (5).
In addition to this, water running through urban and agricultural land in the Murray-Darling basin can flush harmful chemicals, and nutrients that cause algal blooms, into lakes and rivers, having a negative impact on the populations of this species (6).
The Murray hardyhead is also faced with the introduction of invasive species, such as common carp (Cyprinus carpio) or perch (Perca fluviatilis). These species will either compete with the Murray hardyhead for food or predate on it directly (7).