Title Target strength studies on Antarctic silverfish (Pleuragramma antarcticum) in the Ross Sea
Author Azzali, M.; Leonori, I.; Biagiotti, I.; De Felice, A.; Angiolillo, M.; Bottaro, M.; Vacchi, M.
Author Affil Azzali, M., CNR, Istituto di Scienze Marine, Ancona, Italy. Other: Universita di Genova, Italy
Source CCAMLR Science, Vol.17, p.75-104. Publisher: Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), International. ISSN: 1023- 4063
Publication Date 2010
Notes In English GeoRef Acc. No: 309664
Index Terms Antarctica--Ross Dependency; Southern Ocean--Ross Sea; acoustical methods; anatomy; Antarctica; census methods; Chordata; fisheries; geophysical methods; geophysical surveys; juvenile taxa; larvae; models; Nototheniidae; osteology; physiology; Pisces; Pleuragramma antarcticum; Ross Dependency; Ross Sea; soft parts; Southern Ocean; surveys; Vertebrata
Abstract Discusses problems associated with acoustic surveys of non-swimbladder animals including crustaceans, molluscs and fish, and presents data on target strength (TS) of Pleuragramma antarcticum at 38, 120 and 200 kHz using in situ and ex situ measurement and target strength-target length (TL) experimental models. Results indicate that TS- TL relationships of adults differ consistently from those of post-larvae and juveniles. Describes simple model derived from geometrical and acoustic characteristics of different parts of adult P. antarcticum and designed to fit fish life stages from adults to post-larvae and frequencies from 38 to 200 kHz, which can predict experimental TS measured both ex situ and in situ with mean difference -1.5 dB, although differences between predicted and measured TS and some fish lengths were high (from 7.16 to -3.14 dB). Model shows that main contribution to scattering for small fish is from soft tissues and for larger sizes from hard tissues (e.g. skeletal structure), which may explain why small and large fish have different TS-TL relationships.
Publication Type journal article
Record ID 91392