In Situ measurements of acoustic target strengths of siphonophores

• Autorzy: Warren J. D. , Stanton T. K. , Benfield M. C. , Wiebe P. H. , Chu D.
• Konferencja: Proceedings of the 2 nd EAA International Symposium on Hydroacoustics 24-27 May 1999, Gdańsk-Jurata POLAND
• Języki publikacji: EN

Abstrakty

EN

Measurements were made of the acoustic target strengths of siphonophores swimming freely in the ocean. The measurements were made possible by use of a remotely operated vehicle (ROV) on which both acoustics and video camera equipment were mounted. The acoustic transducers and camera were aimed at the same volume of water and data jrom che two sets of devices were co-registered. The cameras were used to help search for and identify the animais and to direct the path of the ROV; sa that ance the animals were jound they would be in or near the acoustic beams. The data show that these gas-bearing zooplankton have relatively high target strengths due to the presence of the gas inclusion. These data are essential in the use of acoustics for quantitatively surveying zooplankton for twa reasons: 1) lt suggests that a relatively small number of siphonophores can dominate che echo in an acoustic survey while other species present may dominate the biomass. 2) Siphonophores are very fragile and, as a result, cannot be reliably captured by use of nets. These data can help in making acoustics a quantitative survey tool for these important animals.

• Wydawca: Polskie Towarzystwo Akustyczne. Oddział Gdański
• Czasopismo: Hydroacoustics
• Rocznik: 1999
• Tom: Vol. 2
• Strony: 11--13
• Opis fizyczny: Bibliogr. 6 poz., rys.

Twórcy

autor

Warren J. D.

• Woods Hole Oceanographic Institution, Woods Hole MA 02543 USA

autor

Stanton T. K.

• Woods Hole Oceanographic Institution, Woods Hole MA 02543 USA

autor

Benfield M. C.

• Louisiana State University, Coastal Fisheries Institute, 218 Wetland Resources, Baton Rouge LA 70803 USA

autor

Wiebe P. H.

• Woods Hole Oceanographic Institution, Woods Hole MA 02543 USA

autor

Chu D.

• Woods Hole Oceanographic Institution, Woods Hole MA 02543 USA

Bibliografia

• 1. E.G. Barham, Siphonophores and the deep scattering layer, Science 140, pp. 826-828, (1963).
• 2. C.S. Clay, Deconvolution of the fish scattering PDF from the echo PDF for a single transducer sonar, J. Acoust. Soc. Am. 73, pp. 1989-1994, ( 1983).
• 3. G.O. Mackie, P.R. Pugh, and J.E. PurcelI, Siphonophore biology, Advances in Marine biology, 24, pp. 98-262, (1987).
• 4. H. Medwin, and C.S. Clay, Fundamentals of Acoustical Oceanography, Boston: Academic Press,1998.
• 5. T.K. Stanton, D. Chu, P.H. Wiebe, L.V. Martin, and R.L. Eastwood, Sound scattering by several zooplankton groups. 1. Experimental determination of dominant scattering mechanisms, J. Acoust. Soc. Am. 103, pp. 225-235, (1998a).
• 6. T.K. Stanton, D. Chu, and P.H. Wiebe, Sound scattering by several zooplankton groups, II. Seattering models, J. Acoust. Soc. Am. 103, pp. 236-253, (1998b).