excluding cases of presence of fish and high amounts of suspended matter from
glaciers.
Acoustical estimates of the theoretical backscattering strength calculated by the
model are very sensitive to changes in density and sound speed contrasts.
In spite of differences in the volume of the water sampled by the acoustical and
optical methods, there is a significant, positive correlation between the volume
backscattering strength determined by the model and measured by the echosounder.
Acknowledgments We would like to thank Emilia Trudnowska for her assistance in preparing
this paper. This work was supported by a Growing of the Arctic Marine Ecosystem (GAME)
project financed from the Polish National Science Centre funds under the no. DEC-2012/04/A/
NZ8/00661 and by an Acoustical estimation of the abundance and spatio-temporal distributions of
the Baltic zooplankton—ZODIAC project financed from the National Science Centre funds under
the no. DEC-2013/09/N/ST10/04177.
References
Anderson VC (1950) Sound scattering from a fluid sphere. J Acoust Soc Am 22:426–431
Chu D, Stanton TK, Wiebe PH (1992) Frequency dependence of sound backscattering from live
individual zooplankton. ICES J Mar Sci 49:97–106
Johnson RK (1977) Sound scattering from a fluid sphere revisited. J Acoust Soc Am 62:375–377
Kogeler JW, Falk-Petersen S, Kristensen A, Pettersen F, Dalen J (1987) Density- and sound speed
contrasts in Sub-Arctic zooplankton. Polar Biol 7:231–235
Krupica KL, Sprules WG, Herman AW (2012) The utility of body size indices derived from
optical plankton counter data for the characterization of marine zooplankton assemblages. Cont
Shelf Res 36:29–40
Medwin H, Clay CS (1998) Fundamentals of acoustical oceanography. Academic Press, San
Diego, p 712
Omori M, Hamner WM (1982) Patchy distribution of zooplankton: behavior, population
assessment and sampling problems. Mar Biol 72:193–200
Rayleigh JWS (1945) Theory of sound. Dover, New York
Stanton TK (1989) Simple approximate formulas for backscattering of sound by spherical and
elongated objects. J Acoust Soc Am 86(4):1499–1510
Stanton TK, Chu D (2000) Review and recommendations for the modelling of acoustic scattering
by fluid-like elongated zooplankton: euphausiids and copepods. ICES J Mar Sci 57:793–807
Trudnowska E, Szczucka J, Hoppe L, Boehnke R, Hop H, Blachowiak-Samolyk K (2012)
Multidimensional zooplankton observations on the northern West Spitsbergen Shelf. J Mar
Syst 98–99:18–25
Wade IP, Heywood KJ (2001) Acoustic backscatter observations of zooplankton abundance and
behaviour and the influence of oceanic fronts in the northeast Atlantic. Deep-Sea Res II Top
Stud Oceanogr 48:899–924
Acoustical and Optical Methods in Arctic Zooplankton Studies
59
glaciers.
Acoustical estimates of the theoretical backscattering strength calculated by the
model are very sensitive to changes in density and sound speed contrasts.
In spite of differences in the volume of the water sampled by the acoustical and
optical methods, there is a significant, positive correlation between the volume
backscattering strength determined by the model and measured by the echosounder.
Acknowledgments We would like to thank Emilia Trudnowska for her assistance in preparing
this paper. This work was supported by a Growing of the Arctic Marine Ecosystem (GAME)
project financed from the Polish National Science Centre funds under the no. DEC-2012/04/A/
NZ8/00661 and by an Acoustical estimation of the abundance and spatio-temporal distributions of
the Baltic zooplankton—ZODIAC project financed from the National Science Centre funds under
the no. DEC-2013/09/N/ST10/04177.
References
Anderson VC (1950) Sound scattering from a fluid sphere. J Acoust Soc Am 22:426–431
Chu D, Stanton TK, Wiebe PH (1992) Frequency dependence of sound backscattering from live
individual zooplankton. ICES J Mar Sci 49:97–106
Johnson RK (1977) Sound scattering from a fluid sphere revisited. J Acoust Soc Am 62:375–377
Kogeler JW, Falk-Petersen S, Kristensen A, Pettersen F, Dalen J (1987) Density- and sound speed
contrasts in Sub-Arctic zooplankton. Polar Biol 7:231–235
Krupica KL, Sprules WG, Herman AW (2012) The utility of body size indices derived from
optical plankton counter data for the characterization of marine zooplankton assemblages. Cont
Shelf Res 36:29–40
Medwin H, Clay CS (1998) Fundamentals of acoustical oceanography. Academic Press, San
Diego, p 712
Omori M, Hamner WM (1982) Patchy distribution of zooplankton: behavior, population
assessment and sampling problems. Mar Biol 72:193–200
Rayleigh JWS (1945) Theory of sound. Dover, New York
Stanton TK (1989) Simple approximate formulas for backscattering of sound by spherical and
elongated objects. J Acoust Soc Am 86(4):1499–1510
Stanton TK, Chu D (2000) Review and recommendations for the modelling of acoustic scattering
by fluid-like elongated zooplankton: euphausiids and copepods. ICES J Mar Sci 57:793–807
Trudnowska E, Szczucka J, Hoppe L, Boehnke R, Hop H, Blachowiak-Samolyk K (2012)
Multidimensional zooplankton observations on the northern West Spitsbergen Shelf. J Mar
Syst 98–99:18–25
Wade IP, Heywood KJ (2001) Acoustic backscatter observations of zooplankton abundance and
behaviour and the influence of oceanic fronts in the northeast Atlantic. Deep-Sea Res II Top
Stud Oceanogr 48:899–924
Acoustical and Optical Methods in Arctic Zooplankton Studies
59