Possibility of position estimates for bottom-dwelling aquatic animals in a small area using ultrasonic coded transmitters and passive monitoring receivers

Abstract

The objective of this study is to examine the possibility of position estimates for bottom-dwelling aquatic animals utilizing small areas by the use of ultrasonic coded transmitters and passive monitoring receivers. We measured the relationship between the rate of signal receptions and the distance from each receiver by deploying ten ultrasonic coded transmitters near the bottom in an array of six receivers in a small area (100 x 250 m). We then tested the weighted means analysis and a multiple regression analysis for estimating the transmitter positions. The relationship between the rate of signal receptions and the distance from each receiver were not always linear, probably because of bottom topography, and there were relatively large errors in both analyses. Therefore, for bottom dwelling aquatic animals utilizing a small area, it is better to make detailed three dimensional maps of reception rates and positions of transmitters in order to estimate finer-scale positions of ultrasonically-tagged animals using ultrasonic coded transmitters and passive monitoring receivers.