A tagging and recapture program was carried out between 1959 and 1970 on large freshwater fish species in the Murrumbidgee and Murray Rivers to determine the patterns of their movement. Tagging was carried out at four main sites Stoney Crossing, Hattah, Hay and Narrandera. At the time internal body tags were found to be the most reliable method of tagging. Adequate numbers of Golden Perch, Macquaria ambigua, and low numbers of Murray Cod Maccullochella peelii peelii and Silver Perch Bidyanus bidyanus were recaptured. It is concluded that up - and downstream movement of M. ambigua from these sites varied. The western two sites at Stoney Crossing and Hattah on the Murray River showed a marked net upstream movement; movement from Hay on the Murrumbidgee showed dispersal both up and downstream, while movement from Narrandera showed a net downstream movement. Within the size range sampled 309-563mm, the larger fish moved significantly less than the smaller fish; when split into upstream and downstream movement, this was only significant for upstream movement.
B. Bidyanus, tagged in the upper two sites, showed a net downstream movement from Narrandera with a single upstream movement from Hay. M. peelii peelii showed only minor movements (up to 141 km) up and downstream from Narrandera, with only one long distance movement from Balranald to Gundagai. Net downstream stream movement of M. ambigua declined as one moved downstream closer to the mouth of the Murray River.