Jumbo Squid (Dosidicus gigas) in situ Target Strength measurements in Northwest Mexico

• Published in: 2013 IEEE/OES Acoustics in Underwater Geosciences Symposium
• Main Authors: Villalobos, H., Manini-Ramos, F., Salinas-Zavala, C., Brehmer, Patrice
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2013
• Subjects: MEXIQUE; PACIFIQUE; [SDV.BA]Life Sciences [q-bio]/Animal biology; Baja; DML
• Online Access: https://hal.science/hal-04378214; https://doi.org/10.1109/RIOAcoustics.2013.6683994

RIO Acoustics 2013, Rio de Janeiro, BRA, 24-/07/2013 - 26/07/2013 In order to convert acoustic abundance indexes into biomass is essential to establish the relationship between squid size dorsal mantle length (DML) and acoustic Target Strength (TS). We had carried out in situ measurement in 2012 off Baja California on Dosidicus gigas. For both frequencies, we found significant differences between modes of measured and predicted TS distributions, 6 and 11 dB for 120 and 38 kHz, respectively. It is known that TS varies with several factors, including echosounder characteristics and transducer frequency and mainly the target orientation in the acoustic beam and many other biological variables. In relation to squid behavior, during the capture operation small fish schools were observed in the area, which may suggest that squid were feeding. Further observations and analysis are necessary in order to obtain reliable TS - DML relationship for jumbo squid before attempting acoustic biomass assessment methods to this important species.