This study quantitatively analyzed the target strength (TS) characteristics of the dotted gizzard shad (Konosirus punctatus) across various fork lengths (FL) and frequency conditions. In July 2023, TS measurements were conducted on six size groups (FL: 14.4–23.5 cm) under free-swimming conditions in a seawater acoustic tank at the Fisheries Resources Research Center in Tongyeong, Korea. A scientific echosounder (EK80, SIMRAD) was used to collect TS data at three frequencies: 38, 70, and 120 kHz. The results showed that TS values increased with fork length, and the 120 kHz frequency exhibited the widest distribution range and distinct bi- or multi-modal patterns. The TS–FL relationships for each frequency were as follows: TS38 kHz = 20·log(FL) ‒ 68.41, TS70 kHz = 20·log(FL) ‒ 70.76, and TS120 kHz = 20·log(FL) ‒ 70.90. Unlike traditional tethered measurement methods, this study obtained TS data under free-swimming conditions, providing values more representative of real-world acoustic survey environments. The findings are expected to serve as foundational data for improving the accuracy of monitoring the distribution and biomass estimation of K. punctatus using hydroacoustic methods.

서 론
재료 및 방법
    실험 샘플
    실험 셋팅 및 음향시스템 구성
    음향자료 분석
결과
    전어의 샘플
    TS의 분포 특성
    TS-FL의 관계식
고 찰
결 론
사 사
References

• 윤은아(제주대학교 해양산업경찰학과 교수) | Euna YOON (Professor, Department of Marine Industry and Maritime Police, Jeju National University, Jeju 63243, Korea)
• 이형빈(국립수산과학원 수산자원연구센터 연구원) | Hyungbeen LEE (Researcher, Fisheries Resources Research Center, National Institute of Fisheries Science, Tongyeong 53064, Korea) Corresponding author
• 이정훈(국립수산과학원 수산자원연구센터 연구원) | Jeong-Hoon LEE (Researcher, Fisheries Resources Research Center, National Institute of Fisheries Science, Tongyeong 53064, Korea)