Estimation of Fish Biomass and Size in Aquaculture Pens Using Digital Echosounder

Current methods for assessment of biomass and size of fish for aquaculture companies require excessive handling of the fish. This induces mortality, slows growth and causes illness. Results produced by these methods are inaccurate, labor intensive and increase production costs. Assessment of biomass and fish size in aquaculture is needed for a number of reasons, including: (a) determining feed rates according to the number and size of fish in each pen, (b) appraisal of growth rates and food conversion factors, (c) inventory of fish required by banks and insurance companies, (d) early detection of fish losses, and (e) determining proper dosages for the treatment of disease. Acoustic systems are used to estimate fish biomass and size in marine and freshwater environments. Attempts to apply acoustic technology to the monitoring of fish biomass and size in the aquaculture industry have failed to produce a cost-effective system for industrial application. We propose to demonstrate the feasibility of an innovative acoustic system based on digital sonar technology using split beam transducers with rotators. Our work plan focuses on modeling and experimental verification of acoustic techniques. Preliminary experiments using analog technology produced results indicating that the new generation digital sonar system is feasible.