Testing of new sampling methods and estimation of size structure of sea bass (Dicentrarchus labrax) in aquaculture farms using horizontal hydroacoustics

Orduna, Carlos; Encina, Lourdes Encina; Rodríguez-Ruiz, Amadora; Rodríguez-Sánchez, Victoria

doi:10.1016/j.aquaculture.2021.737242

Cited by 6 publications

(5 citation statements)

References 27 publications

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“…Potential reasons may include the following, (i) Related to the diel rhythm of fish, the aggregation behavior of fish is more evident during the daytime than at nighttime (Appenzeller and Leggett, 1992). Hence, the beam from the hydroacoustic detector radiates on the acoustic scattering cross section of the upper fish, and it immediately reflects on the detector's receiving, resulting in the beam not penetrating the upper fish and detecting the lower fish (Orduna et al, 2021). (ii) Related to the anti-predatory behavior of fish, the light intensity during the daytime is favorable to the predatory activities of predators, and many fish migrate to shallow waters or hide under some shelters such as aquatic plants and rocks to avoid predators (R ̌ıha et al, 2015;Christensen and Persson, 1993;Wolter and Bischoff, 2001;Prchalováet al, 2008;Mehner, 2012), hydroacoustic surveys usually actively avoid these areas considering safety, but they return to deeper water during the nighttime, resulting in the detection of fish during the daytime density being higher than at nighttime.…”

Section: Factors Influencing Changes In Fish Densitymentioning

confidence: 99%

Effects of season and diel cycle on hydroacoustic estimates of density, Target Strength, and vertical distribution of fish in Yudong Reservoir, a plateau deep water reservoir in southwest China in a plateau deep

et al. 2023

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Hydroacoustics is a non-invasive fish stock assessment sampling technique that plays an important role in fishery science and management. However, non-standard hydroacoustic surveys could lead to biased results, and the factor of the sampling period (e.g., season and diel cycle) is extremely critical as it can greatly affect hydroacoustic results. Efforts to improve the accuracy and credibility of the hydroacoustic survey results are getting more and more attention. Thus, we conducted two diel hydroacoustic surveys in situ in summer and winter to detect whether there were diel and seasonal differences in density, Target Strength (TS) and vertical distribution of fish. The results indicated that nighttime had significantly higher fish mean density than daytime in summer and winter. No significant difference between summer and winter daytime, however, significant difference between summer and winter nighttime, but this bias could be accepted from the fisheries management perspective; The mean TS of the summer daytime was significantly higher than that of summer nighttime, winter daytime and winter nighttime, but there were no significant differences among summer nighttime, winter daytime, and winter nighttime, mainly due to mean TS may be overestimated from fish schooling behavior during summer daytime; The fish vertical distribution had significant seasonal correlations and was more dispersed in different water layers during the nighttime, proving that the assessment was better at nighttime than during the daytime. Consequently, the hydroacoustic surveys in Yudong Reservoir and other similar plateau deep water reservoirs should be performed at nighttime, which will yield relatively accurate density and TS, and dispersed vertical distribution of fish.

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Section: Factors Influencing Changes In Fish Densitymentioning

confidence: 99%

Effects of season and diel cycle on hydroacoustic estimates of density, Target Strength, and vertical distribution of fish in Yudong Reservoir, a plateau deep water reservoir in southwest China in a plateau deep

et al. 2023

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“…Target strength is described as the echo intensity of the fish in decibels (dB) when it is placed on the acoustic axis of the transducer (Manik, 2015). Target strength distributions may be used to assess the size structure of a fish stock (Orduna et al, 2021;Wanzenböck et al, 2020). To accomplish this, several models illustrating the relationship between fish size and target strength should be used, from multispecies general equations to particular species-specific equations (Love, 1971;Frouzova et al, 2005;Lilja et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Fish Stock Status Assessment in Alue Naga Waters Using A 200 Khz Single Beam Echosounder

et al. 2023

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Monitoring fish stocks is an important part of sustainable management of fisheries resources. Conducting the current evaluation is very difficult since there are no reliable data on the potential for fisheries in the waters surrounding Banda Aceh city. The hydroacoustic method was used for the first time in the waters of Alue Naga, located north of Banda Aceh, to evaluate the condition of fish stocks. A single beam scientific echosounder with a frequency of 200 kHz was used to collect hydroacoustic data in the area. The collected data was then processed using the Sonar5-Pro software. Cell integration was carried out at an interval of 10 meters vertically with an elementary sampling distance (ESD) of 200 m. While the volume backscattering strength (SV) value tends to be the highest in intermediate layers, the target strength (TS) value was found to be maximum in deeper layer, reaching a maximum value of -49.46 dB at a depth of 51–60 m. Area density value (#.ha-1) was found to be the highest at a depth of 11-20 m, while Biomass (g.ha-1) at a depth of 21-30 m was the highest among other depth layers with a value of 1558 g.ha-1. According to the in-situ catches of Carangoides, Selaroides, Aphareus, Variola, and Priacanthidae, there are a number of potential reef fish resources in the waters of Alue Naga. The findings of this study strongly support the conclusion that the hydroacoustic method effectively provides comprehensive information on the horizontal and vertical distribution of fish in Alue Naga waters.

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Section: Introductionmentioning

confidence: 99%

“…Acoustic detection technology based on scientific echosounders is widely used in the field of fishery resource investigation [1][2][3][4][5][6][7][8][9]. This type of echosounder performs vertical or horizontal detection underwater by transmitting and receiving acoustic waves [1]. The sound pressure is converted to an electrical signal by the transducer and amplified by the circuits, and echo integration is used to analyze the target scattering characteristics [2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…Although the formula is reasonable, the definition of transducer array gain G is too complex. Most calculation methods rely on equipment and calibration parameters [1,3,5,6,[11][12][13] and do not mention the processing of the beam pattern. EK80 is currently one of the most mainstream broadband split-beam echo sounders and is considered to be the next-generation device to replace EK60 [12,13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Broadband Scattering Characteristic Quantization Technique for Single Fish Based on a Split-Beam Echosounder

Ai,

Li,

Yao

et al. 2023

Fishes

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The utilization of broadband quantization data increases the possibility of practical applications for fish target recognition based on the acoustic scattering theory. However, the quantification of broadband data is more complex than that of narrowband systems, requiring consideration of the broadband characteristics of split-beam transducers, seawater absorption, and circuits. This paper elucidates the scatterer acoustic field equation, transducer power equation, and signal processing flow in split-beam broadband quantization technology for engineering applications. A broadband calculation model based on transducer parameters is proposed to enhance the generalization ability of broadband quantization technology to different types of sonar. The classical echo integration method is combined with Fourier transform to meet the requirements of target strength (TS) estimation under broadband signals. This paper includes a series of experiments to prove the rationality and effectiveness of the method. The results demonstrate that the provided calculation model can more accurately reflect the backscattering characteristics of the scatterer, but certain errors remain. This article analyzes the sources of errors and validates the effectiveness of the new TS calculation method.

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Testing of new sampling methods and estimation of size structure of sea bass (Dicentrarchus labrax) in aquaculture farms using horizontal hydroacoustics

Cited by 6 publications

References 27 publications

Effects of season and diel cycle on hydroacoustic estimates of density, Target Strength, and vertical distribution of fish in Yudong Reservoir, a plateau deep water reservoir in southwest China in a plateau deep

Effects of season and diel cycle on hydroacoustic estimates of density, Target Strength, and vertical distribution of fish in Yudong Reservoir, a plateau deep water reservoir in southwest China in a plateau deep

Fish Stock Status Assessment in Alue Naga Waters Using A 200 Khz Single Beam Echosounder

Broadband Scattering Characteristic Quantization Technique for Single Fish Based on a Split-Beam Echosounder

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