Acoustic species identification of schooling fish

Korneliussen, R. J., Heggelund, Y., Eliassen, I. K., and Johansen, G. O. 2009. Acoustic species identification of schooling fish. - ICES Journal of Marine Science, 66: 1111-1118.The development of methods for the acoustic identification of fish is a long-term objective aimed at reducing uncertainty in acoustic-survey estimates. The relative frequency response r(f) measured simultaneously at several frequencies is one of the main acoustic features that characterize the targets, but the relationship between nearest neighbours, school morphology, and environmental and geographical data are also important characteristics in this context. The number of acoustic categories that can be separated with a high spatial resolution is limited by the stochastic nature of the measurements. Because the acoustic categorization of larger ensembles is more reliable than for single targets, spatial smoothing of the backscattering within the school boundaries before that process allows the separation of more categories than is possible with the raw, highly resolved data. Using the mean r(f) of an entire school gives even more reliable categorization, but determining whether or not the school is monospecific sets a new challenge. This problem is evaluated here. The methods are tested and verified. Identification of acoustic categories with similar acoustic properties is done for schooling fish, although the results have limited spatial resolution. The reliability of the categorization is further improved when knowledge of school morphology and geographical distribution of the species are taken into account.

[1]  G. Pedersen,et al.  The relative frequency response derived from individually separated targets of northeast Arctic cod (Gadus morhua), saithe (Pollachius virens), and Norway pout (Trisopterus esmarkii) , 2009 .

[2]  R. Korneliussen,et al.  THE LARGE SCALE SURVEY SYSTEM-LSSS , 2006 .

[3]  Alain Hillion,et al.  Narrowband acoustic identification of monospecific fish shoals , 1996 .

[4]  Rolf J. Korneliussen,et al.  The Bergen echo integrator post-processing system, with focus on recent improvements , 2004 .

[5]  E. Ona,et al.  An operational system for processing and visualizing multi-frequency acoustic data , 2002 .

[6]  K. Foote.  Calibration of acoustic instruments for fish density estimation : a practical guide , 1987 .

[7]  Rudy J. Kloser,et al.  Species identification in deep water using multiple acoustic frequencies , 2002 .

[8]  E. Murphy,et al.  Interpretation of acoustic data at two frequencies to discriminate between Antarctic krill (Euphausia superba Dana) and other scatterers , 1993 .

[9]  John K. Horne,et al.  Acoustic approaches to remote species identification: a review , 2000 .

[10]  Rolf J. Korneliussen,et al.  Measurement and removal of echo integration noise , 2000 .

[11]  David N. MacLennan,et al.  Fisheries and plankton acoustics: past, present, and future , 1996 .

[12]  Verified acoustic identification of Atlantic mackerel , 2004 .

[13]  Ø. Ulltang,et al.  Biology and population dynamics of the Norwegian spring- spawning herring , 1980 .

[14]  Neil R. Andersen,et al.  Oceanic sound scattering prediction , 1977 .

[15]  S. Fässler,et al.  Multifrequency scattering properties of herring (Clupea harengus) and Norway pout (Trisopterus esmarkii) , 2004 .

[16]  E. Ona,et al.  Synthetic echograms generated from the relative frequency response , 2003 .

[17]  Paul G. Fernandes,et al.  Multifrequency backscattering properties of Atlantic herring (Clupea harengus) and Norway pout (Trisopterus esmarkii) , 2007 .

[18]  S. Georgakarakos,et al.  Artificial neural networks as a tool for species identification of fish schools , 1996 .

[19]  M. Furusawa,et al.  Effective and accurate use of difference in mean volume backscattering strength to identify fish and plankton , 2002 .

[20]  Paul G. Fernandes,et al.  Proposals for the collection of multifrequency acoustic data , 2008 .

[21]  Harald Gjøsæter,et al.  The population biology and exploitation of capelin (Mallotus villosus) in the barents sea , 1998 .

[22]  Kenneth G. Foote,et al.  Postprocessing system for echo sounder data , 1991 .