Acoustical and Optical Methods in Arctic
Zooplankton Studies
Lukasz Hoppe and Joanna Szczucka
Abstract Concurrent acoustical and optical measurements have a great potential to
describe zooplankton distribution over large temporal and spatial scales. It is difficult to collect complete information on zooplankton distribution with traditional
methods (e.g. nets), that provide discrete and low resolution data on distribution of
zooplankton biomass, abundance, as well as community structure of zooplankton.
Acoustic sounding makes environmental studies fast, non-intrusive, and relatively
cheap with high temporal and spatial resolution. LOPC delivers real-time information on zooplankton abundance and size spectra. In this review we present the
results of study on zooplankton distribution in two fjords of Spitsbergen in the
summer of 2013. Data for this study was collected during simultaneous profiling
with high frequency (420 kHz) echosounder and LOPC along the main fjord axes.
Zooplankton size spectra obtained by LOPC were used as input parameters in
“high-pass” model of sound scattering on fluid-like particles. Model output values
of acoustic backscattering strength were compared with values obtained by echosounding. In most cases there was a good agreement between measured and
modeled values, except conditions of very low zooplankton abundance and events
of fish presence. Zooplankton size structure is helpful in validating and refinement
of “high-pass” acoustic model for specific set of scatterers. This gives a possibility
to determine the theoretical backscattering strength of zooplankton. Implementing
two complementary methods allows to obtain fast and more complete information
on zooplankton distribution.
Keywords High-frequency acoustics Á Arctic zooplankton Á LOPC Á Sound
scattering model
L. Hoppe (&) Á J. Szczucka
Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55,
81-712 Sopot, Poland
e-mail: hoppe@iopan.gda.pl
© Springer International Publishing Switzerland 2015
T. Zielinski et al. (eds.), Impact of Climate Changes on Marine Environments,
GeoPlanet: Earth and Planetary Sciences, DOI 10.1007/978-3-319-14283-8_5
51
Zooplankton Studies
Lukasz Hoppe and Joanna Szczucka
Abstract Concurrent acoustical and optical measurements have a great potential to
describe zooplankton distribution over large temporal and spatial scales. It is difficult to collect complete information on zooplankton distribution with traditional
methods (e.g. nets), that provide discrete and low resolution data on distribution of
zooplankton biomass, abundance, as well as community structure of zooplankton.
Acoustic sounding makes environmental studies fast, non-intrusive, and relatively
cheap with high temporal and spatial resolution. LOPC delivers real-time information on zooplankton abundance and size spectra. In this review we present the
results of study on zooplankton distribution in two fjords of Spitsbergen in the
summer of 2013. Data for this study was collected during simultaneous profiling
with high frequency (420 kHz) echosounder and LOPC along the main fjord axes.
Zooplankton size spectra obtained by LOPC were used as input parameters in
“high-pass” model of sound scattering on fluid-like particles. Model output values
of acoustic backscattering strength were compared with values obtained by echosounding. In most cases there was a good agreement between measured and
modeled values, except conditions of very low zooplankton abundance and events
of fish presence. Zooplankton size structure is helpful in validating and refinement
of “high-pass” acoustic model for specific set of scatterers. This gives a possibility
to determine the theoretical backscattering strength of zooplankton. Implementing
two complementary methods allows to obtain fast and more complete information
on zooplankton distribution.
Keywords High-frequency acoustics Á Arctic zooplankton Á LOPC Á Sound
scattering model
L. Hoppe (&) Á J. Szczucka
Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55,
81-712 Sopot, Poland
e-mail: hoppe@iopan.gda.pl
© Springer International Publishing Switzerland 2015
T. Zielinski et al. (eds.), Impact of Climate Changes on Marine Environments,
GeoPlanet: Earth and Planetary Sciences, DOI 10.1007/978-3-319-14283-8_5
51