Raja Bidin Raja Hassan
Marine Fishery Resources Development

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TURTLE HEARING CAPABILITY BASED ON ABR SIGNAL ASSESMENT Anton Yudhana; Sunardi Sunardi; Jafri Din; Syed Abdullah; Raja Bidin Raja Hassan
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 8, No 2: August 2010
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v8i2.620

Abstract

Sea turtles have existed for millions of years. International Union for Conservation of Nature (IUCN) has reported that the Hawksbill Turtle (Eretmochelys imbricata) is classified as critically endangered. Turtle excluder device (TED) deployment on shrimpnet fisheries is needed for turtle conservation.TED using sound technique is challenge method in fisheries development.The knowledge on turtle hearing capability is limited. The auditory brainstem response (ABR) assessment is method to determine turtle hearing capability. Turtle hearing assessment is basis to design TED. The objective of this paper is to determine turtle hearing cability by analyze its ABR spectral.The subject is Hawksbill turtle with number 2 turtles ie: 3 and 2 years. The measurement was taken at Pusat Pengurusan Penyu (Turtle Management Centre) Padang Kemunting Masjid Tanah Melaka Malaysia. The results shows that turtle 3 years have peak power frequencies 50.78, 101.6, 152.3, 304.7, 355.5, 457, and 507.8Hz respectively whereas the spectral amplitude is ranging 0.03-32.44% spectral. Turtle 2 years has peak power at 457Hz in whole stimulus frequencies while the spectral amplitude is ranging 0.01-2.5% spectral.
SWIMBLADDER ON FISH TARGET STRENGTH Sunardi Sunardi; Anton Yudhana; Jafri Din; Raja Bidin Raja Hassan
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 6, No 2: August 2008
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v6i2.561

Abstract

This paper discusses of Target Strength (TS) for the Selar boops (Oxeye scad) and Megalaspis cordyla (Torpedo scad), the most commercially fish in Malaysia. TS can be determined from in situ measurements and calculation using acoustic fish model. TS value, depth, and position (x-y-z) of fish targeted can be viewed from echogram using FQ-80 Analyzer by in situ measurement. X-ray imaged can be deployed to develop the acoustic fish model. The percentage of length and upper surface area for swimbladder to body fish of Selar boops more than Megalaspis cordyla can be measured after X-ray process. The percentage of width and volume of swimbladders to its each body are no significantly difference for both fish. These data of swimbladder physic are supports the result from in situ measurement which TS of Megalaspis cordyla have more than Selar boops.