The Sea to Hume fishway construction program was a $77M program that spanned ten years — the biggest fish passage rehabilitation program ever undertaken in Australia. The Sea to Hume program included the installation of automated Passive Integrated Transponder (PIT) technology to monitor the movements of migratory fish. To be effective, the program requires a population of tagged fish being present within the river. Naturally occurring population processes dictate that the tagged fish population slowly turns-over through time.