New imaging sonar technologies for marine fisheries monitoring

Investigating fish dynamics – such as fish size, characteristics and behaviour – in ‘opaque’ temperate inshore waters is technically challenging due to environmental limitations like light conditions, turbidity and tides. 

Scientists at Plant & Food Research, along with colleagues from the University of Canterbury assessed new imaging sonar technologies for use in marine fisheries monitoring. They compared imaging sonars to the ‘gold standard’ stereovision camera systems in a highly controlled (tank-based setting) using a multi-factorial design (including multiple species of various sizes). 

The scientists assessed the utility of the imaging sonar in a natural, highly turbid, estuarine environment and compared the outcomes to more conventional capture techniques (trapping). 

The study found that imaging sonars provide non-destructive, environmentally robust, accurate analytical capabilities with high sampling power. Although less accurate (but comparable) to gold standard stereo-camera techniques, imaging sonars are advantageous, because they greatly increase sampling capabilities in low light and transient conditions. The results validate imaging sonar technology for use in nearshore marine environments and has broad application to fisheries, ecology and marine sciences. 

Funding was provided by MBIE within the Wildfish 2030 programme (C11X203)

Journal Reference:

Cook D, Middlemiss K, Jaksons P, Davison W, Jerrett A 2019. Validation of fish length estimations from a high frequency multi-beam sonar (ARIS) and its utilisation as a field-based measurement technique. Fisheries Research. 218: 59-68 https://doi.org/10.1016/j.fishres.2019.05.004