Ex Situ Target Strength Measurements of Rockfish (<i>Sebastes schlegeli</i>) and Striped Beakperch (<i>Oplegnathus fasciatus</i>)

Abstract

The rockfish (Sebastes schlegeli) and striped beakperch (Oplegnathus fasciatus) were released in marine ranching areas in Korea, Japan, and China to maintain fishery resources in coastal areas. To estimate the density and biomass of fishery resources, the target strength (TS) of target marine organisms is needed to scale integrated volume backscattering coefficients. In this study, the target strength–length (TS–L) relationship for live rockfish and striped beakperch was derived using ex situ methods at a frequency of 200 kHz. The TS-L function for rockfish and striped beakperch can be expressed as TSAvg. = 20logTL − 69.25 (R2 = 0.35) and TSAvg. = 20logFL − 67.01 (R2 = 0.31), respectively. These results can be used to assess the growth, density, and abundance of the two species using acoustics.

Keywords

• target strength
• <i>Sebastes schlegeli</i>
• <i>Oplegnathus fasciatus</i>
• ex situ