How much fish is hidden in the surface and bottom acoustic blind zones

Scalabrin, C., Marfia, C., and Boucher, J. 2009. How much fish is hidden in the surface and bottom acoustic blind zones? - ICES Journal of Marine Science, 66: 1355-1363.This paper presents results from the ALLEGRO-07 survey that was carried out from 1 to 15 September 2007 across the continental shelf in the Bay of Biscay by the RV “Thalassa”. The main objectives were to conduct experiments with a medium-sized, autonomous underwater vehicle (AUV) equipped with a fishery-acoustic scientific payload. This was needed to overcome the difficulties of sampling the surface and bottom blind zones, which are inaccessible to conventional, vessel-mounted transducers used for acoustic surveys in the Bay of Biscay. The AUV acoustic datasets from four dives were compared with those from the research vessel. The results were expressed for the nautical-area-scattering coefficient (s A ) and biomass estimates. The AUV provided higher s A measurements than did the vessel. For particular environmental and fish-distribution patterns, the biomass estimated by the AUV was more than ten times that estimated by the vessel alone. The results presented indicate the magnitude of the error that may occur in acoustic surveys, if the biomass in the two blind zones is undetected.

[1]  K. Foote.  Fish target strengths for use in echo integrator surveys , 1987 .

[2]  Olav Rune Godø,et al.  Behaviour of herring (Clupea harengus L.) towards an approaching autonomous underwater vehicle , 2004 .

[3]  Paul G. Fernandes,et al.  Autonomous underwater vehicles: future platforms for fisheries acoustics , 2003 .

[4]  J. Bendat,et al.  Random Data: Analysis and Measurement Procedures , 1971 .

[5]  R. Mitson.  Underwater noise of research vessels:Review and recommendations , 1995 .

[6]  Frederick Armstrong,et al.  Antarctic Krill Under Sea Ice: Elevated Abundance in a Narrow Band Just South of Ice Edge , 2002, Science.

[7]  James G Bellingham,et al.  Robotics in Remote and Hostile Environments , 2007, Science.

[8]  Acoustic data collected during and between bottom trawl stations: consistency and common trends , 2007 .

[9]  Beatriz A. Roel,et al.  A two-stage biomass dynamic model for Bay of Biscay anchovy: a Bayesian approach , 2008 .

[10]  John Paniagua,et al.  NEMO: A mission to search for and return to Earth possible life forms on Europa , 2005 .

[11]  Jon Sáenz,et al.  Climate, oceanography, and recruitment: the case of the Bay of Biscay anchovy (Engraulis encrasicolus) , 2008 .

[12]  R. H. Love.  Target strength of an individual fish at any aspect , 1977 .

[13]  Paul G. Fernandes,et al.  An investigation of avoidance by Antarctic krill of RRS James Clark Ross using the Autosub-2 autonomous underwater vehicle , 2003 .

[14]  Hélène de Pontual,et al.  Evidence of underestimation of European hake growth in the Bay of Biscay, and its relationship with bias in the agreed method of age estimation , 2006 .

[15]  P. Stevenson,et al.  Addendum: Fish do not avoid survey vessels , 2000, Nature.

[16]  D. MacLennan,et al.  Fisheries acoustics , 2004, Reviews in Fish Biology and Fisheries.

[17]  Egil Ona,et al.  Acoustic sampling and signal processing near the seabed: the deadzone revisited , 1996 .

[18]  Victor C. Strasburger,et al.  Review and Recommendations , 1983 .

[19]  Pierre Fréon,et al.  Analysis of vessel influence on spatial behaviour of fish schools using a multi-beam sonar and consequences for biomass estimates by echo-sounder , 1996 .

[20]  R. Francis,et al.  The relationship between Pacific hake (Merluccius productus) distribution and poleward subsurface flow in the California Current System , 2006 .

[21]  Rb Miston,et al.  Underwater noise of research vessels , 1995 .

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

[23]  Noël Diner,et al.  MOVIES-B: an acoustic detection description software. Application to shoal species' classification , 1993 .

[24]  Pablo Carrera,et al.  Comparison of airborne lidar with echosounders: a case study in the coastal Atlantic waters of southern Europe , 2006 .

[25]  J. Bendat,et al.  Random Data: Analysis and Measurement Procedures , 1987 .