Authors : Azrul Mahfurdz, Sunardi , Hamzah Ahmad, Syed Abdullah and Nazuki Sulong
Abstract: An echo strength measurement of green turtle and fish is proposed in this study using echo sounder. The measurements were conducted in a research tank by employing 200 kHz transmit pulse and reflected echo recorded at 1 MHz sampling rate using high speed analog digital converter. The animals used in the study were green turtle at the age of 1, 3, 12 and 18 years old together with three species of fish which is Indian Mackerel, Indian Scad and Bigeye Scad. The fish echo strength was compared to the turtle echo strength value. The average value shows that echo strength of adult turtles and fish is different. The echo strength of the fish recorded in range of-39.546 to -38.110 dB while the echo strength of the turtle was in range of -37.310 to -34.769 dB. The comparison of echo strength between different ages of turtles shows that the turtle echo strength increases as the ages increases. The results also show significant differences between each angle measurement of the turtle body. The highest average echo strength is from 18 years old turtle at plastron angle which shows-34.769 dB. The acoustic strength value range recorded for all aged of turtle at carapace angle is -36.514 to - 34.871 dB and at plastron angle is-36.371 to -34.769 dB. The comparison of the different ages of turtles demonstrated that the turtle echo strength increases as the age increases. The results also show that there is significant differences echo strength value for each turtle bodies.
Azrul Mahfurdz, Sunardi , Hamzah Ahmad, Syed Abdullah and Nazuki Sulong, 2017. Acoustic Scattering Strength of Sea Turtle and Fish using Echo Sounder. Journal of Engineering and Applied Sciences, 12: 3747-3751.