Experimental Investigation of an Acoustic Method to Estimate Fish Abundance Using Culture Nets

Abstract

Using an acoustic method fish abundance in many culture nets has been measured and the results statistically analyzed. The acoustic system consists of two parts, an echo-integrator which gives distribution density and a specially designed sectorscanning sonar which provides distribution volume. By matching the measured numbers to actual ones, parameters concerning the target strength of fish and the attenuation by schooling fish are derived. These parameters are compared with actual observations.