Acoustic method for discriminating plankton from fish in Lake Dom Helvecio of Brazil using a time varied threshold

시간변량역치를 이용한 브라질 Dom Helvecio호수의 어류와 플랑크톤 생물의 음향적인 구분을 위한 기법

  • Kang, Myounghee (Department of Maritime Police and Production system, The institute of Maritime Industry, Gyeongsang National University)
  • 강명희 (경상대학교 해양경찰시스템학과, 해양산업연구소)
  • Received : 2012.06.11
  • Accepted : 2012.10.29
  • Published : 2012.11.30


An acoustic method for discriminating plankton from fish, in Lake Dom Helvecio of Brazil, is developed. The flow of data from this method is comprised of time varied threshold (TVT), dilation filter, bitmap and mask functions. The TVT can, of itself, precisely explain how to select an appropriate value. The final results of the echogram, which only shows plankton by masking fish signals, is used to examine the acoustic density of plankton by depth and time. The results indicate that the acoustic density of the plankton is at a depth of between 5m to 15m, its density is especially high at 10m to 15m. The results of the acoustic density of plankton by time indicate that May 7 is higher in density than May 8. Future study plans include the use of net samples, environmental datasets to identify the abundance and ecology described by the Chaoborus spp. from other species.




  1. Bezerra-Neto JF and Pinto-Coelho RM. 2008. Morphometric study of Lake Dom Helvecio, Parque Estadual do Rio Doce (PERD), Minas Gerais, Brazil: a re-evaluation. Acta Limnol Bras 20, 161-167.
  2. Eckmann R. 1998. Allocation of echo integrator output to small larval insect (Chaoborus sp.) and mediumsized (juvenile fish) targets. Fish Res 35, 107-113.
  3. Foote KG, Knudsen HP, Vestnes G, MacLennan DN and Simmonds EJ. 1987. Calibration of acoustic instruments for fish-density estimation: a practical guide. ICES Coop Res Rep, 44.
  4. Godlewska M and Jelonek M. 2006. Acoustical estimates of fish and zooplankton distribution in the Piaseczno reservoir, Southern Poland. Aquat Ecol 40, 211-219.
  5. Jurvelius J, Knudsen FR, Balk H, Marjomaki TJ, Peltonen H, Taskinen J, Tuomaala A and Viljanen M. 2008. Echo-sounding can discriminate between fish and macroinvertebrates in fresh water. Fresh Biol 53, 912-923.
  6. Kang M, Furusawa M and Miyashita K. 2002. Effective and accurate use of difference in mean volume backscattering strength to identify fish and plankton. ICES J Mar Sci 59, 794-804.
  7. Kang M, Nakamura T and Hamano A. 2011. The application of GIS in analyzing acoustical and multidimensional data related to artificial reefs ground. J Kor Soc Fish Tech 47, 222-233.
  8. Kim HY, Hwang BK, Lee YW, Shin HO, Kwon JN and Lee KH. 2011. Hydro-acoustic survey on fish distribution and aggregated fish at artificial reefs in marine ranching area. J Kor Soc Fish Tech 47, 139-145.
  9. Kloser RJ, Ryan T, Sakov P, Williams A and Koslow JA. 2002. Species identification in deep water using multiple acoustic frequencies. Can J Fish Aquat Sci 59, 1065-1077.
  10. Knudsen FR and Larsson P. 2009. Discriminating the diel vertical migration of fish and Chaoborus flavicans larvae in a lake using a dual-frequency echo sounder. Aqua Liv Resour 22, 273-280.
  11. Knudsen FR, Larssonb P and Jakobsenb PJ. 2006. Acoustic scattering from a larval insect (Chaoborus flavicans) at six echosounder frequencies: Implication for acoustic estimates of fish abundance. Fish Res 79, 84-89.
  12. Lee SJ, Lee YW, Kim JI, Oh TY, Hwang BK, Kim BY and Lee KH. 2010. Target strength estimation of dominant species in marine ranching ground of Jeju coastal water by KRM model. J Kor Soc Fish Tech 46, 157-163.
  13. Myriax. 2012. Help file 5.2.21 for Echoview.
  14. Oda S and Hanazato T. 2008. Diel vertical migration patterns in two populations of Chaoborus flavicans larvae (Diptera: Chaoboridae) in response to fish kairomones. J Limnol 67, 93-99.
  15. Pinto-Coelho RM, Giani A and Sperling EV (Editors). 1994. Ecology and Human impact on lakes and reservoirs in Minas Gerais with special reference to future development and management strategies. University Federal Minas Gerais, Brazil, 1-193.
  16. Pinto-Coelho RM, Bezerra-Neto F, Miranda FB, Mota TG, Resck R, Santos AM, Maia-Barbosa PM, Mello NAST, Marques MM, Campos MO and Barbosa FAR. 2008. The inverted trophic cascade in tropical plankton communities: Impacts of exotic fish in the Middle Rio Doce lake district, Minas Gerais, Brazil. Braz J Biol 68 (4, Suppl.), 1025-1037.
  17. Rudstam LG, Knudsen FR, Balk H, Gal G, Boscarino BT and Axenrot T. 2006. Acoustic characterization of Mysis relicta at multiple frequencies. Can J Fish Aquat Sci 65, 2769-2779.
  18. Tan T, Kang M, Tao J, Li X and Huang D. 2011. Hydroacoustic survey of fish density, spatial distribution, and behavior upstream and downstream of the Changzhou Dam on the Pearl River, China. Fish Sci 77, 891-901.

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