Hydroacoustic target strength vs. fish length revisited: Data of caged, free-swimming European whitefish (Coregonus lavaretus L.) suggest a bi-phasic linear relationship under a limited range of tilt angles
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F20%3A00538913" target="_blank" >RIV/60077344:_____/20:00538913 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1016/j.fishres.2020.105620" target="_blank" >https://doi.org/10.1016/j.fishres.2020.105620</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.fishres.2020.105620" target="_blank" >10.1016/j.fishres.2020.105620</a>
Alternative languages
Result language
angličtina
Original language name
Hydroacoustic target strength vs. fish length revisited: Data of caged, free-swimming European whitefish (Coregonus lavaretus L.) suggest a bi-phasic linear relationship under a limited range of tilt angles
Original language description
To develop specific target strength (TS) fish length relationships using 38 kHz and 120 kHz split beam echosounders, we measured TS (dB) in five size groups (5-59 cm total length) of European whitefish (Coregonus lavaretus) swimming freely in a net cage of 4m diameter and 8m height. For 120 kHz, we deployed down-looking (dorsal aspect) as well as upwards-looking (ventral aspect) transducers, whereas 38 kHz measurements were taken for the dorsal aspect only. The ventral aspect dataset revealed stronger TS values especially for the larger length classes. The dorsal aspect datasets of both frequencies were not significantly different across all lengths and both showed a steep increase of the relationship in small sizes (5-20 cm) which levelled off in the larger sizes (> 20 cm). For 120 kHz the slope of a linear regression of TS vs. log fish length was 29.8 for fish between 5-20 cm (much higher than the generally proposed slope of 20), while in fish > 20 cm the slope was 10.7 which is far below the generally proposed value. We advocate considering a potential bi-phasic linear regression of the log length TS relationship for all species whenever a large size range of fish is studied, encompassing significant proportions below and above approximately 20 cm total length.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10618 - Ecology
Result continuities
Project
<a href="/en/project/GAP504%2F12%2F1186" target="_blank" >GAP504/12/1186: Hydroacoustical distinguishing between fish and bubbles, and quantification of methane bubble ebullition in freshwater reservoirs of temperate zone</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Fisheries Research
ISSN
0165-7836
e-ISSN
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Volume of the periodical
229
Issue of the periodical within the volume
5
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
10
Pages from-to
1-10
UT code for WoS article
000539099200024
EID of the result in the Scopus database
2-s2.0-85085351653