Study on Fish Density using Split Beam Accoustic System and its relation with Oceanographic Factors at Sunda Strait

Abstract

The utility of marine fish resources in a certain seawater can be optimazed if fish density data in that area is known. The hydroacoustic devices such as split beam acoustic system can be applied to obtain the accurate fish density. Study on fish density by using this acoustic system and its relation with oceanographic factors was conducted in Sunda Strait in last March 1998.R.V. Madidihang (300 GT) and various marine research instruments were employed during acoustic cruising tracks. The result show that fish densities in upper sea water layer of cruising legs are 1 to 4 fish/1000 m3 with fish length until 63 cm and at deep seawater layer 65 – 258 fish/1000 m3 with fish length until 178 cm. The fish density is abundant at front area because seawater mass exchange of different temperature and salinity. There is indication that fish densities are found surrounding thermocline layer.