A Study on the Characteristics of Fishery Resources Distribution in Coastal Waters of Yeongil Bay Using Acoustic Survey

Abstract

In this study, the identification of dominant fish species in the East Sea was conducted using the dB-difference method. The survey was conducted using the two frequencies of 38 and 120 kHz in transect 6 of the southern part of the East Sea. Information on fish species was identified using fishing gear and e-DNA, and the dominant target fish species were selected and analyzed as cod, anchovy, common squid, and herring. The dB-difference range for each fish species was set to −0.86 dB < ∆MVBS 38–120 kHz < 0.82 dB for cod and to the range of 2.66 dB < ∆MVBS 38–120 kHz < 2.84 dB for anchovy. The dB-difference of the common squid was set to −0.36 dB < ∆MVBS 38–120 kHz < 1.25 dB and to the range of 0.88 dB < ∆MVBS 38–120 kHz < 2.28 dB for herring; the fish species were then identified in the echograms. When comparing the results of swimming depths by fish species and previous studies, cod was detected mainly at the bottom of the sea, and anchovy and common squid were detected mainly at a depth of 50 m. Herring was detected to be mainly distributed in water depths from 50 to 150 m.