Distinguish Sea Turtle and Fish Using Sound Technique in Designing Acoustic Deterrent Device

Azrul Mahfurdz, Sunardi Sunardi, H. Ahmad, Syed Abdullah, Nazuki Nazuki

Abstract


Acoustic is a common method for underwater object classification and to observe fish schools or other marine animals in their environment, but it was never applied on sea turtle. Knowledge about turtle detection using sound is very limited and there are no target strength (TS) recorded before. In this study, an echo voltage reference methodincorporating standard target was used to measure ex situ target strength of two Green Turtle (Chelonian mydas) and three species of fish (Indian scad, Indian Mackerel and Bigeyescad). The echo signal of animals has been observed from echosounder output and every envelope of the echo was digitized at a sampling rate 1MHz using high speed analog to digital converter (USB‑1208HS). The finding shows a significant difference between fish and turtles aged 18 years old. The result also demonstrates that TS increase as age of turtle increase. This result is considered important in designing an acoustic deterrent device. The result reveals that size, surface, and animal body part influence in determining target strength value.


Keywords


Acoustic deterrent device, target strength, echo voltage, marine animal detection

Full Text:

PDF

References


McDaniel, C.J., Crowder, L.B. and Priddy J.A. “A spatial analysis of sea turtle abundance and shrimping intensity in the U.S Gulf of Mexico,” Proceedings of The Nineteenth Annual Symposium On Sea Turtle Conservation and Biology, 1999, p. 65.

Arauz, R. “Implementation of the turtle excluder device (TED) by the shrimp fleet of Pacific Central America,” Proceedings of The 18th International Symposium Sea Turtle Biology and Conservation, 2000, pp. 104-105.

Hamann, M., Ibrahim, K. and Limpus, C. Status of leatherback turtle in Malaysia, Indian Ocean South East Asian (IOSEA) Leatherback Turtle Assessment, 2006.

Gilman, E., Gearhart J., Price B., Eckert S., Miliken H., Wang J., Swimmer Y., Shiode D., Abe O., Peckham S.H., Chaloupka M., Hall M., Mangel J., Shigueto J.A., Palzell P., and Ishizaki A. “Mitigating sea turtle by catch in coastal passive net fisheries,” Fish and Fisheries, 2010, 11: 57-88.

Yeo, B.H., Squires, D., Ibrahim, K., Gjertsen, H., Syed Mohd. Kamil, S.K., Zulkifli, R., Groves, T., Hong, M.C. and Tan, C.H. “Fisher profiles and perceptions of sea turtle fishery interactions: case study of East Coast Peninsular Malaysia,” The WorldFish Center Discuss. The WorldFish Center, Penang, Malaysia, 2007.

Bull, L.S. “A review of methodologies for mitigating incidental catch of seabirds in New Zealand fisheries,” Science & Technical Publishing Department of Conservation, 2007.

Lokkeborg, S. “Best practices to mitigate seabird bycatch in longline, trawl and gillnet fisheries-efficiency and practical applicability,” Marine Ecology Progress Series, 2011, 435:285-303.

Stone, G.S., Cavagnaro, L., Hutt, A., Kraus, S., Baldwin, K. and Brown, J., Reactions of Hector’s dolphins to acoustic gillnet pingers. Sciences & Research Unit, Science Technology and Information Services, Department of Conservation, Welington, New Zealand, 2000.

Cox, T.M., Read, A.J., Swanner, D., Urian, K. and Waples, D. ” Behavioral responses of bottlenose dolphins, Tusiops truncates, to gillnets and acoustic alarms,” Biological Conservation, 2003, 115: 203-212.

Gazo, M., Gonzalvo, J. and Aguilar, A. “ Pingers as deterents of bottlenose dolphins interacting with trammel nets,” Fisheries Research, 2008, 92: 70-75.

Berggren, P., Carlstrom, J. and Tregenza, N., Mitigating of small cetacean bycatch; evaluation of acoustic alarms (MISNET). Final Report to the European Commission, 00/031,2002.

Lenhardt, M. “ Sea turtle auditory behavior,”Abstract. J. Acoust. Soc. Am., 2002, 112(5):2314.

Yudhana, A., Turtle Hearing Classification for Turtle Excluder Devices Design. Ph.D Thesis. Universiti Teknologi Malaysia, Malaysia, 2011.

Southwood, A., Fritschhes, K., Brill, R. and Swimmer, Y. “Sound, chemical, and light detection in sea turtles and pelagic fishes:sensory based approaches to bycatch reduction in longline fisheries,” Endangered Species Research, 2008, 5:225-238.

Hodges R.P., Underwater acoustic analysis, design and performance of sonar (United Kingdom : John Wiley & Son, 2010).

Stanton, T.K., Wiebe, P.H. and Chu, D. “ Difference between sound scattering by weakly scattering spheres and finite length cylinders with applications to sound scattering by zooplankton,” J. Acoust. Soc. Am.,1998, 103(1):254-264.

Stanton, T.K. and Chu, D. “Review and recommendations for the modeling of acoustic scattering by fluid like elongated zooplankton: Euphausiids and Copepods,” ICES Journal of Marine Science, 2000, 57:793-807.

Mukai, T., Lida, K., Ando, Y., Mikami, H., Maki, Y. and Matsukura, R. “Measurements of swimming angles, density and sound speed of the krill Euphausia Pacifica for target strength estimation,” MTTS/IEEE TECHNO -OCEAN ’04,2004,pp. 383-388.

Stanton T.K. “On acoustic scattering by a shell covered seafloor,” J. Acoust. Soc. Am., 2000, 108(2): 551-555.

Warren, J.D., Stanton, T.K., McGehee, D.E. and Chu, D. “ Effect of animal orientation on acoustic estimates of zooplankton properties,” IEEE Journal of Oceanic Engineering, 2002, 27:130-138.

Nakken, O. and Olsen, K. “Target strength measurements of fish,” Rapports et Procès-Verbaux des Réunions Conseil International pour l'Exploration de la Mer., 1977, 170: 52-69.

Kalinowski, J. Dyka, A. and Kilian, L. “Target strength of krill,” Polish Polar Research, 1980, 1(4):147-153.

Arnaya, N. Sano, N. and Lida, K. “ Studies on acoustic target strength of squid. I. Intensity and energy target strength,” Bull. Fac. Fish. Hokkaido Univ.,1988, 39(.3):187-200.

Benoit Bird, K.J. and Au, W.W.L. “Target strength measurements of Hawaiian Mesopelagic boundary community animals,” J. Acoust. Soc. Am., 2001, 110(2):812-819.