Passive acoustic localization for Sciaenid habitat in coastal water of Taiwan

There are many Sciaenid species found in coastal water of Taiwan, and most of them can generate sound in the spawning season. However, due to overfishing, the populations of these high economic value fishes have been greatly decreased. To study and protect Sciaenid, whose habitat should be identified, seasonal protection zones should be set up. In this study, easy and low‐cost measure of using passive sonar is proposed to map the habitat in the field. Measurement and analysis of Sciaenid sound were performed to investigate its acoustic characteristic, and frequency range was found to be 350 to 1500 Hz. The statistical distribution of sound levels can be built up by enough field measurement; therefore source levels can be defined in this method. In addition, the transmission loss of in‐site shallow water was studied to compute the real decaying factor (TL=n*log R) of the survey site. By using three sonobuoys, with known source level distribution and transmission loss, the distance of possible habitat ca...