A major limitation in studying the behaviour of fish in the rivers of the Murray-Darling Basin is that high turbidity (muddy water) makes direct observation of fish impossible.  The dual-frequency identification sonar (DIDSON) is a unique, high-definition piece of equipment that uses sound beams to produce almost photographic quality underwater images. For fish studies, the … Continue reading An assessment of a Dual-Frequency Identification Sonar (DIDSON) in the Murray Darling Basin