From 2011 – 2016, DPI Fisheries completed detailed Passive Integrated Transponder (PIT) monitoring at ten (10) vertical-slot fishways in the Murray-Darling Basin. The aim of this presentation is to detail fish passage outcomes at newly constructed vertical-slot fishways, with a focus on two native species, Golden Perch (Macquaria ambigua; 0.1 – 0.5 m) and Murray Cod (Maccullochella peelii; 0.1 – 1.0 m), both of which demonstrate a facultative potamodromous migration pattern.
Analysis of fishway performance centered on the percentage of PIT tagged fish that approached the fishway entrance, passage efficiency once inside the fishway, ascent time, and the number of failed ascents where the fish returned downstream. PIT monitoring results will be discussed against criteria established by DPI Fisheries to assess the effectiveness of vertical-slot fishways in passing facultative migrating species. Fish passage trends among sites will be discussed against vertical-slot design criteria such as fishway slope (1:20 to 1:30), pool turbulence, and slot size which are generally conservative compared to northern hemisphere design standards due to the poor swimming capacities of Australian native fish. Behavioural observations such as repetitive repeat ascents will also be discussed.