Fig 1 - uploaded by Anderson Ladino
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Diagram of the directivity D(θ) calculation in the x-y plane, where θ is the observation angle; θ = 0 • is the direction of the fish's head, θ = 180 • is the direction of the fish's tail, and θ = 270 • is the direction of the center of the echosounder´s transducer.
Source publication
Swimbladder inflation is a significant matter in intensive fish farming, since it is related to larval survival rate and the morphological quality of individuals. In this work, we propose a non-invasive acoustic technique using ultrasound to monitor the swimbladder development of gilthead seabream (Sparus aurata) in tanks. The fundamental hypothesi...
Contexts in source publication
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... incident acoustic wave was considered to be a plane wave along the positive y-axis direction, impinging on the ventral part of the larvae, at an ultrasonic working frequency of 200 kHz ( Fig. 1). To guarantee the proper density mesh, the meshing domain was developed by free and adjusted tetrahedral finite elements for each component with a mesh size of λ/10 (Ihlenburg, 1998). The far-field backscattered acoustic pressure field was estimated by evaluating the Helmholtz-Kirchhoff integral on the boundary between the surrounding ...
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... Exp1 data (Fig. 10a), the presence of an inflated swimbladder Table 3 Mean TS, number of traces (n), percentage of swimbladder inflated (%SBI) and the median standard length (Ls) values obtained from the analysis of unit traces of larvae between 6-dph and 16-dph (Exp1). Parameters obtained from the linear regression adjustments of the logarithm of the ...
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... evidenced at 7-dph, with 2% of sampled larvae with a swimbladder. Under control conditions, at 7-dph, a TS of 81.4 dB was recorded, whereas at 16-dph it came to 74.8 dB (6.6 dB higher than at 7-dph). For Exp2 (Fig. 10b), the swimbladder inflation process was similar to Exp 1. At 8-dph, 5% of the sampled larvae had developed a swimbladder, with non-inflated swimbladders observed the previous days. Under control conditions, the median TS increased by 4.1 dB from 8-dph to 15-dph (from 72.6 dB up to 68.5 dB). From these data, it is shown that after ...
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... higher background level introduced under production conditions, mainly by the presence of gas bubbles from the aeration system. For Exp1, under production conditions, the median TS value was of 76.3 dB. At 16-dph with 50% of larvae with a developed swimbladder, a TS value of 70.5 dB was seen, meaning an increase of 5.8 dB compared to 7-dph (see Fig. 11a). For Exp2, the median TS increase was smaller: 2 dB, from 70.5 dB at 8-dph up to 68.5 dB at 16-dph (see Fig. ...
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... system. For Exp1, under production conditions, the median TS value was of 76.3 dB. At 16-dph with 50% of larvae with a developed swimbladder, a TS value of 70.5 dB was seen, meaning an increase of 5.8 dB compared to 7-dph (see Fig. 11a). For Exp2, the median TS increase was smaller: 2 dB, from 70.5 dB at 8-dph up to 68.5 dB at 16-dph (see Fig. ...
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... we wondered if the TS vs length relationship could be obtained on monitoring the larval growth during their early stages, once the first swimbladder inflation was detected. Linear regression adjustments between TS and log 10 (L s ) were performed, (see Table 5). Firstly, we analysed the results obtained under production conditions (dashed line in Fig. 12). Secondly, we explored the results under control conditions (solid line in Fig. 12). Good correlations were obtained in both ...
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... growth during their early stages, once the first swimbladder inflation was detected. Linear regression adjustments between TS and log 10 (L s ) were performed, (see Table 5). Firstly, we analysed the results obtained under production conditions (dashed line in Fig. 12). Secondly, we explored the results under control conditions (solid line in Fig. 12). Good correlations were obtained in both ...
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... we had experimentally confirmed our main assumption, we wondered if the acoustic detection of inflation processing could be automated. Results for measurements under control conditions with an automatic SED algorithm had also shown good agreement with numerical predictions considering the background noise due to multiple scattering (see Fig. 10). Slight quantitative discrepancies can be noted for the results in Exp2 (Fig. 10), where the measured TS data were larger than the numerical estimation. This could be related to the presence of residual bubbles in the tank leading to an underestimation of the background noise value applied to the numerical results. Qualitative trends ...
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... acoustic detection of inflation processing could be automated. Results for measurements under control conditions with an automatic SED algorithm had also shown good agreement with numerical predictions considering the background noise due to multiple scattering (see Fig. 10). Slight quantitative discrepancies can be noted for the results in Exp2 (Fig. 10), where the measured TS data were larger than the numerical estimation. This could be related to the presence of residual bubbles in the tank leading to an underestimation of the background noise value applied to the numerical results. Qualitative trends under control conditions were the same for both experiments. An almost constant ...
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... the acoustic TS measurements, the general trend can be described as follows: during the first post-hatching days it is almost constant, with a low TS value recorded, related to the scattering of residual bubbles, larval food and larvae without an inflated swimbladder. As of the first swimbladder inflation, the TS values then increase over time ( Fig. 9 and Fig. 10). This enables acoustic detection of when the swimbladder inflation begins. From this moment, the inflation rate and swimbladder area on one hand and the early larval growth on the other can be monitored by measuring and processing the TS automatically, providing a non-invasive technique to monitor swimbladder inflation and larval ...
Citations
... Desde el punto de vista acústico la estimación de la biomasa se basa en la determinación del factor de blanco (TS, de sus siglas en inglés Target Strength), definido como la relación entre las intensidades acústicas incidente y retrodispersada cuando un objetivo es insonificado [3]. El TS se utiliza como un factor de escala decisivo para la abundancia de peces, debido a que se ha establecido relaciones entre TS y la longitud de los peces [4]. ...
The scientific echo sounder that are currently used to estimate the biomass of species of commercial interest are configure so that the measurements of the acoustic data have a pulse duration for each working frequency, to establish the most appropriate to detect objects in relation to size, for which it is of interest to know and understand this variation of the backscattered field of an object for the different pulse durations emitted. Acoustic simulations are important to determine and characterize the acoustic dispersion of fish. In this work, a methodology for simulating the real temporal pulse of an echosounder using the meshless numerical simulation of fundamental solutions (MFS) method is proposed. For this, the decomposition of the spectral components necessary to adequately reproduce the original pulse emitted by the different pulse durations of the echosounder has been carried out. It has been possible to evaluate the algorithm in a first part by calculating the variation of the target strength (TS) and the reconstruction of the return pulse for different reference geometries of known sizes in the shape of a sphere and in a second part in the application for a real case of a 3D swimbladder using a computerized tomography (CT) of a Bluefin tuna.
... In this context, we have extended the current knowledge on the ecotoxicity of DEET by selecting the marine coastal fish gilthead sea bream (Sparus aurata) as target organism exposed at environmentally relevant concentrations (μg L − 1 ) in a flow-through system. The fish gilthead sea bream has recently gained importance in research studies as a model marine organism due to its relevance in aquaculture production and wide geographical distribution (Alomar et al., 2022;Ladino et al., 2022). ...
DEET is one of the most frequently detected insect repellents in the environment reaching concentrations of several μg L⁻¹ in surface water. There is scarce information available regarding its mode of action in non-target organisms. Here, we have used an integrated metabolomic and transcriptomic approach to elucidate the possible adverse effects of DEET exposure in the marine fish gilthead sea bream (Sparus aurata). Individuals were exposed at an environmentally relevant concentration of DEET (10 μg L⁻¹) for 22 days in a continuous flow-through system. Transcriptomic analysis revealed 250 differentially expressed genes in liver, while metabolomic analysis identified 190 differentially modulated features in liver and 98 in plasma. Multi-omic data integration and visualization allowed elucidation of the modes of action of DEET exposure, including: energy depletion through the disruption of carbohydrate and amino acids metabolisms, oxidative stress leading to DNA damage, lipid peroxidation, and damage to cell membrane and apoptosis. Activation of xenobiotic pathway as well as the inmune-inflammatory reaction was evidenced in the present work.
... In this context, we have extended the current knowledge on the ecotoxicity of DEET by selecting the marine coastal fish gilthead sea bream (Sparus aurata) as target organism exposed at environmentally relevant concentrations (μg L − 1 ) in a flow-through system. The fish gilthead sea bream has recently gained importance in research studies as a model marine organism due to its relevance in aquaculture production and wide geographical distribution (Alomar et al., 2022;Ladino et al., 2022). ...
