Hydroacoustics in Aquaculture: Using hydroacoustics to inform aquaculture production of salmon and macroalgae
Production Assessment and Species Selection Tools Project
This PhD will investigate the potential for using acoustic sensing systems at offshore and land-based salmon aquaculture sites and macroalgae cultivation sites. The system(s) will collect data (e.g. images/video, hydroacoustic backscatter) in situ, over several deployments at salmon and macroalgal production sites. They will be evaluated for their ability to detect individual fish, macroalgae biomass, etc., and generate information for use in monitoring and production estimates.
Hydroacoustic systems to be tested include imaging sonars and scientific split-beam echosounders. Imaging sonars are high-resolution multibeam echosounders. These echosounders capture video-like data constructed from high-frequency sound rather than light. Individual fish that pass within the fan-shaped sampling volume can be measured and tracked as they swim, providing size and movement (behaviour) data. Resolution and sampling range differ based on the echosounder manufacturer, as well as certain environmental factors (e.g. packing density of fish, entrained air in the water column).
In contrast to imaging sonars, scientifically engineered and calibrated single/split beam echosounders offer the ability to generate quantifiable information using the response strength of features in the water column. These echosounders record the acoustic response in high resolution throughout the projected sound beam, several times per second and down to hundreds of meters if needed. The advantage of this type of echosounder, therefore, is the ability to quantitatively sample biomass throughout the entire water column (or net pen) in high resolution in time and space. This type of data will likely be well-suited
for understanding fish density (shoaling), vertical distribution in the net pens, and total biomass over time.
Echoview software facilitates data processing of the hydroacoustic device mentioned, including converting the large data files to useable, transportable information on fish size, quantity, and behaviour (at the individual and shoal level). This project would allow devices to be tested in land-based facilities and evaluated against the needs for monitoring in offshore aquaculture settings.
