title: Detecting Atlantic herring by parametric sonar.
abstract: The difference-frequency band of the Kongsberg TOPAS PS18 parametric sub-bottom profiling sonar, nominally 1-6 kHz, is being used to observe Atlantic herring. Representative TOPAS echograms of herring layers and schools observed in situ in December 2008 and November 2009 are presented. These agree well with echograms of volume backscattering strength derived simultaneously with the narrowband Simrad EK60/18- and 38-kHz scientific echo sounder, also giving insight into herring avoidance behavior in relation to survey vessel passage. Progress in rendering the TOPAS echograms quantitative is described.
authors.affiliation: Institute of Marine Research, P.O. Box 1870 Nordnes, 5817 Bergen, Norway. olavrune@imr.no
authors.forename: Olav Rune
authors.initials: OR
authors.lastname: Godo
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Foote
authors.forename: Johnny
authors.initials: J
authors.lastname: Dybedal
authors.forename: Eirik
authors.initials: E
authors.lastname: Tenningen
authors.forename: Ruben
authors.initials: R
authors.lastname: Patel
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000818:Animals; D001267:Atlantic Ocean; D001362:Avoidance Learning; D001522:Behavior, Animal; D004867:Equipment Design; D005399:Fishes / Q000502:physiology*; D009664:Norway; D011156:Population Density; D011825:Radar / Q000295:instrumentation; D012815:Signal Processing, Computer-Assisted; D012919:Social Behavior; D013018:Sound Spectrography; D013550:Swimming; D013997:Time Factors; D014159:Transducers