Pubblicazione scientifica

A novel upward-looking hydroacoustic method for improving pelagic fish surveys

FILONE TECNOLOGICO	TEMA
economia circolare e sostenibilità
trasformazione e commercializzazione

RIASSUNTO

For ethical reasons and animal welfare, it is becoming increasingly more important to carry out ecological surveys with a non-invasive approach. Information about fish distribution and abundance in the upper water column is often fundamental. However, this information is extremely hard to obtain using classical hydroacoustic methods. We developed a rigid frame system for pushing upward looking transducers of the scientific echo sounder (38 and 120 kHz) in front of the research vessel. The efficiency of the new approach for monitoring juvenile fish at night was investigated by comparing the results with a quantitative fry trawl in the Římov Reservoir in the Czech Republic. The experimental setup enabled comparisons for the 0–3 m and 3–6 m depth layers, which are utilized by almost all juvenile fish in summer. No statistically significant differences in the estimated abundance of juveniles were found between the two sampling methods. The comparison of abundance estimates gathered by the two frequencies were also not significantly different. The predicted mean lengths from acoustic sampling and the trawl catches differed by less than 10 mm in all comparisons. Results suggest that mobile hydroacoustic upward-looking systems can fill the methodological gap in non-invasive surveying of surface fishes.

DATA

Data di pubblicazione: 06/07/2017

AUTORI

BARAN ROMAN
JUZA TOMAS
TUSER MICHAL
BALK HELGE
BLABOLIL PETR
CECH MARTIN
DRASTIK VLADISLAV
FROUZOVA JAROSLAVA
JAYASINGHE ASANKA D
KOLIADA IEVGEN
MRKVICKA TOMAS
MUSKA MILAN
RICARD DANIEL
SAJDLOVA ZUZANA
VEJRIK LUKAS
KUBECKA JAN

RIVISTA

Scientific Reports, 7, 4823

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