J
Juha Lilja
Researcher at University of Jyväskylä
Publications - 16
Citations - 279
Juha Lilja is an academic researcher from University of Jyväskylä. The author has contributed to research in topics: Salmo & Target strength. The author has an hindex of 10, co-authored 16 publications receiving 264 citations.
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Upstream migration activity of cyprinids and percids in a channel, monitored by a horizontal split-beam echosounder
TL;DR: In this paper, a 200 kHz digital echosounder with two split-beam transducers was aimed horizontally to monitor the upstream migration activity of fish, from 24 April to 28 June, in Aijalansalmi channel (mean width 35 m, length 700 m, and maximum depth 5 m).
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Side-aspect target strength of Atlantic salmon (Salmo salar), brown trout (Salmo trutta), whitefish (Coregonus lavaretus), and pike (Esox lucius)
TL;DR: L'indice de reflexion acoustique laterale (TS) a ete mesure en utilisant un sondeur de 200 kHz, afin d'etudier la relation entre l'sindice TS et la taille, le poids et the surface du poisson.
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Spawning run of Atlantic Salmon ( Salmo salar ) in the River Tornionjoki monitored by horizontal split-beam echosounding
TL;DR: In this paper, fixed location split-beam horizontal echosounding was used to assess the size and timing of the Atlantic salmon (Salmo salar) spawning run in the River Tornionjoki.
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Simulation and experimental measurement of side-aspect target strength of Atlantic salmon (Salmo salar) at high frequency
TL;DR: Numerical simulations and empirical measurements of swimming Atlantic salmon showed strong variation in TS, both when the side-aspect angle was changed and when the swimbladder was bent to the direction of the sonar beam.
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Perch (Perca fluviatilis) and pikeperch (Sander lucioperca) in the diet of the great cormorant (Phalacrocorax carbo) and effects on catches in the Archipelago Sea, Southwest coast of Finland
TL;DR: Investigation of cormorant diet in the Archipelago Sea, Southwest coast of Finland found pikeperch and perch made up 0.04–10% and 21–43% of the diet respectively, by mass, while the length distribution of perch eaten by c Cormorant was more similar to thelength distribution in purse seine samples rather than to that in commercial catches.