Video Validation
Typically fish counters are not 100% accurate in enumerating fish passing through their sensor arrays whether they are infra red, resistance or acoustic based. To provide a measure of counter accuracy, video has often been used during periods of non-turbid river discharge to provide an estimate of counter efficiency (Aprahamian et al 1995, Fewings 1987; Welton et al. 1987; Dunkley 1991, McCubbing and Ward 1999, McCubbing and Ignace 2000). Counter efficiency, the number of fish counted compared to those observed may be calculated for upstream migrants and downstream migrants independently, during periods of differing environmental conditions and over differing size classes.
Click here to see a small validation video (Warning: 1.4meg file)
New smaller low light intensity underwater cameras allow easier video validation of counter efficiencies. Cameras and video validation equipment are available for lease/rental. For details contact us.
Fish counter analysis a may also involve interpretation of "graphical output" from the Logie counter. A typical example of an upstream fish from the Lardeau River, near Nelson BC is shown below.
