Targets strength of freshwater fish with single beam echosounder

Abstract

Cyprinu scarpio, Oreochromis niloticus, Pangasius, Anguilla sp, Ospronemus goramy and Serrasalmus sp are the types of fresh fish consumed widely by Indonesian society. Each type of fish has different acoustic backscatter strength influenced by meat, swim bladder and fish behavior at the time of data collection. This acoustic backscatter value has a decibel unit (dB). The purpose of this research is to get the value of single fish acoustic backscatter from those species. Data was recorded using single beam equipment frequency 200 kHz (cruzpro and Simrad EK-15 echosounder equipment). The results show the TS value of the six fish varies between -53 dB to -41dB. The TS relationship with length has a correlation coefficient value (R) greater than 0.5, which means that fish length has contribution more than 50%. Data was observed in a July 2015 trial using the same equipment and software. It was found that fish with the same length, which is 19 cm of different species (C. carpio, Pangasius and O. niloticus) but had different weights, turned out to have the different TS values. It is assumed that the characteristics of each fish body are different.