Assessing Target Strength, Abundance, and Biomass for Three Commercial Pelagic Fish Species along the East Coast of Peninsular Malaysia Using a Split-Beam Echo Sounder

Abstract

ABSTRACT Hashim, M.; Aziz, M.F.H.A.; Hassan, R.B., and Hossain, M.S., 2017. Assessing target strength, abundance, and biomass for three commercial pelagic fish species along the east coast of Peninsular Malaysia using a split-beam echo sounder. Decapterus maruadsi (round scad), Megalaspis cordyla (torpedo scad), and Selar boops (oxeye scad) are commercially important small pelagic fish species of Malaysia. Despite their commercial and ecological value, little is known about their target strength (TS), spatial and vertical distributions, and biomass estimates. A split-beam acoustic survey was performed in the east coast of Peninsular Malaysia (ECPM) in March–June 2009. The calibrated echo sounder allowed determination of TS, estimation of fish density (spatial distribution) and biomass, and produced density maps along depth gradients (vertical distribution). The TS–length relationships indicated that the logarithmic TS was proportional to the squared length. Additional water parameters that included salini...