Acta Adriatica, Vol. 53 No. 3, 2012.
Original scientific paper
Comparisons of two research vessels’ properties in the acoustic surveys of small pelagic fish
Iole LEONORI
; Istituto di Scienze Marine (ISMAR-CNR), Largo Fiera della Pesca, 60125 Ancona, Italy
Vjekoslav TIČINA
orcid.org/0000-0002-3686-9563
; Institute of Oceanography and Fisheries (IOF), Šet. I. Meštrovića 63, 21000 Split, Croatia
Andrea DE FELICE
; Istituto di Scienze Marine (ISMAR-CNR), Largo Fiera della Pesca, 60125 Ancona, Italy
Olja VIDJAK
; Institute of Oceanography and Fisheries (IOF), Šet. I. Meštrovića 63, 21000 Split, Croatia
Leon GRUBIŠIĆ
; Institute of Oceanography and Fisheries (IOF), Šet. I. Meštrovića 63, 21000 Split, Croatia
Armin PALLAORO
; Institute of Oceanography and Fisheries (IOF), Šet. I. Meštrovića 63, 21000 Split, Croatia
Abstract
Acoustic surveys in the Adriatic Sea have been performed annually by the research vessels “Dallaporta” and “Bios”, equipped with SIMRAD echo-sounders (EK-500 and EK-60), and working with 38 kHz split-beam transducer (ES38B). Since the vessels have different characteristics and use different pelagic trawls for fish sampling, there is uncertainty regarding the comparability of the results obtained. In order to evaluate comparability of the results, a comparison between research vessels was performed. That included comparisons of vessels’ noise, acoustic data collection, and fish samples composition and size structure analyses. The noise generated by both vessels was sufficiently low to allow a single fish detection up to 200 m depth. Acoustic data collected by the two vessels showed similar trends, no significant differences in average SA-values, and highly significant correlation between SA-values. Therefore, unbiased acoustic data collected by vessels could be combined in future stock assessments. Concerning collection of fish samples, anchovy resulted as the most abundant species in the samples collected by both vessels even if size compositions of anchovy were significantly different.
Keywords
Echo surveys; research vessels; acoustic properties; data acquisition; Adriatic Sea
Hrčak ID:
97272
URI
Publication date:
30.12.2012.
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