Unfortunately, this species is only considered threatened in the ACT. This is despite there being recorded impact from fire, sedimentation, poor riparian conditions, invasive species and flow diversion over much of its range. It has been lost from the Murrumbidgee River and probably large sections of its range in NSW and Vic.
Unfortunately for Blackfish it doesn't seam to matter what size they are. All but the largest can be swallowed by trout not much over 30cm in length. Despite this blackfish do ok in areas with trout so long as the habitat, particuarly cobbles with spaces between and under them, is in good condition. If the habitat is sedimented up its a different story for the blackfish.