Distribution and Biomass Using Acoustic Method of the Squid Watasenia scintillans Near Dok-do, East Sea of Korea

摘要

The spatial distribution and abundance of fish species was estimate near Dok-do, East Sea of Korea by conducting midwater trawl survey with hydroacoustic method. Acoustic and midwater trawl data were collected onboard the R7V Tamgu 21 during 7-8 March2016. Acoustic data were collected at the frequencies of 38 and 120 kHz and converted to nautical area scattering strength (m2/nmile2). Species are distributed mainly over an extent of 30-55 m, generally around southwest of Dok-do; the squid Watasenia scintillans was the dominant species found. The length-weight function and target strength of squid and other fishes were used to estimate the W. scintillans stock at 2499.1 tons and other fish at 43.8 tons during the winter season. The hydroacoustic method offers an approach for the determination of the biomass and vertical and spatial distributions of species aggregating near Dok-do, East Sea of Korea.