Study of underwater sound effects relation to current velocity and Siganus sp. population in seaweed cultivation area

Abstract

Underwater sound is one of the interesting phenomena in the ocean. Underwater sounds can impact marine organisms, especially fish and mammals. One of the organisms that can be influenced by underwater sound is the Siganus fish. This study aims to determine sound propagation with a certain level of fish pest repellents about the surface currents velocity and Siganus canaliculatus. population in seaweed cultivation areas. This research was conducted in a seaweed cultivation area in Baubau City, Southeast Sulawesi, Indonesia, in May-July 2022. The tool used is a seaweed pest repellent Ver.04 (Usirikan Ver 03). Underwater sound, at a strength level of 76.19-83.09 dB, can propagate quickly at 60 m in diameter of the sea area. The farthest distance multiplied at a strength of 62.41-69.30 dB can reach 150 m in diameter of the sea area. The fish population (S. canaliculatus) was not found in the seaweed cultivation area, with a sound level of 62.41 dB. The population of Siganus fish is around 2-4 ind/m2 at a sound level of 48.62 dB. Underwater sound with a sound level above 50 dB can impact the population of S. canaliculatus. Seaweed fish repellent can significantly affect behavior. of S. canaliculatus