Physiological factors causing natural variations in acoustic target strength of fish

Ona, Egil

doi:10.1017/s002531540003424x

Cited by 231 publications

(187 citation statements)

References 16 publications

Supporting

Mentioning

153

Contrasting

Unclassified

Order By: Relevance

“…During sample treatment, the fish sample was deep frozen within 30~50 s using the shock freezing method and kept at -50°C until processing (Farrant et al, 1977;Ona, 1990). The swim bladder, however, is easily damaged by external shocks and can be percolated by water.…”

Section: Resultsmentioning

confidence: 99%

Determining the target strength bambood wrasse (Pseudolabrus japonicus) using Kirchhoff-ray mode

Kusdinar¹,

Hwang²,

Shin³

2014

Journal of the Korean society of Fisheries Technology

View full text Add to dashboard Cite

Although ex situ target strength (TS) measurements using dual-and split-beam systems have become the primary approach of estimating fish abundance, theoretical model estimation is a powerful tool for verifying the measurements, as well as for providing values when making direct measurements is difficult. TS values for 20 samples of live bambooleaf wrasse (Pseudolabrus japonicus) whose target length (TL) ranged between 13.7 and 21.3 cm were estimated theoretically using the Kirchhoff-ray mode model, and the TS values for 18 live fish samples were additionally measured at ~0º tilt angle to the swimming aspect using a tethered method at a frequency of 120 kHz to verify the theoretical values. The digitizing intervals used to extract the fish body and swim bladder morphology in the X-ray photographs significantly affected the calculated TS patterns, but variations based on the speed of sound and density ratio values for the general range of fish flesh were relatively small (within 1 dB). Close agreement was observed between the measured and theoretical TS values, and the correlation between the average TS and body length of the fish could be calculated accurately as = 20logTL (cm) -71.6 using the theoretical method.

show abstract

Section: Resultsmentioning

confidence: 99%

Determining the target strength bambood wrasse (Pseudolabrus japonicus) using Kirchhoff-ray mode

Kusdinar¹,

Hwang²,

Shin³

2014

Journal of the Korean society of Fisheries Technology

View full text Add to dashboard Cite

show abstract

“…Following Boswell et al (2007), we recognize that the calculation of biomass is inherently biased because S v is a measure of all of the scattering within a volume of water-not that specific to individual fish or size ranges-and is dependent on TS, which can vary with orientation and fish condition (Ona 1990;Simmonds and MacLennan 2005). The conversion of TS into an appropriate estimate of SL relies on the proper scaling between TS and SL.…”

Section: Discussionmentioning

confidence: 99%

Seasonal Estimates of Fish Biomass and Length Distributions Using Acoustics and Traditional Nets to Identify Estuarine Habitat Preferences in Barataria Bay, Louisiana

Boswell

Wilson²,

Macrae

et al. 2010

Mar Coast Fish

View full text Add to dashboard Cite

We conducted hydroacoustic, gill‐net, and push trawl surveys to quantify changes in habitat‐specific fish size and biomass in shallow (<2‐m) estuarine waters of Barataria Bay, Louisiana, in order to evaluate essential fish habitat. Surveys were conducted monthly between June 2003 and May 2004 among regions located along a north—south salinity gradient. The fish length distributions derived from the gill‐net and push trawl catches showed moderate concordance with the measured target strength distributions, indicating that our integrated approach more effectively characterized the fish community than using only a single gear type would have. Acoustic estimates showed that biomass was highest during fall (mean ± SE; 2.30 ± 0.27 g/m3) and next highest in spring (1.49 ± 0.20 g/m3), with relatively low biomass during summer (0.70 ± 0.14 g/m3) and winter (0.86 ± 0.14 g/m3); pelagic fish biomass from nets was low during winter (53.9 ± 14.9 grams per unit effort [gpue]) but relatively high in fall (846.1 ± 207.2 gpue), spring (774.3 ± 175.5 gpue), and summer (620.3 ± 140.7 gpue). Oyster habitat supported a greater biomass of pelagic fish (acoustic survey: 1.54 ± 0.15 g/m3; gill‐net survey: 467.3 ± 81.0 gpue) than soft‐bottom habitat (acoustic: 0.94 ± 0.11 g/m3; gill‐net: 315.2 ± 54.8 gpue). Among regions, the greatest biomass of pelagic fish was observed at polyhaline stations (acoustic: 1.78 ± 0.19 g/m3; gill‐net: 654.3 ± 136.5 gpue), followed by mesohaline (acoustic: 1.18 ± 0.15 g/m3; gill‐net: 378.5 ± 79.1 gpue) and oligohaline stations (acoustic: 0.82 ± 0.12 g/m3; gill‐net: 228.3 ± 50.2 gpue). Gill‐net biomass was linearly related to the acoustic biomass estimates of small pelagic fish. The complementary, multigear approach proved to be useful in evaluating habitat use and may be particularly helpful in identifying and monitoring ecosystem reference points to evaluate change and in standardizing ecosystem‐based assessment approaches.

show abstract

“…Japanese eel Anguilla japonica (Yamada et al 2004). Furthermore, Ona (1990) found for several fish species that changes in swimbladder volume are inversely related to changes in the size of various visceral organs, including the gonads. Thus, for fish in which the swimbladder serves as a hydrostatic organ and changes in the size of visceral organs may affect swimbladder volume, an abrupt increase in the size of an organ, e.g.…”

Section: Discussionmentioning

confidence: 99%

Bathymetric segregation of spawning stages in the Atlantic sardine Sardina pilchardus

Ganias¹,

Nunes²

2011

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The present study analyzed the spatio-temporal pattern of spawning aggregations of the Atlantic sardine Sardina pilchardus using a large set of reproductive data derived from 5 daily egg production method (DEPM) surveys conducted off Portugal and the Gulf of Cadiz. Similar to previous results for the Mediterranean sardine, sardines in the Atlantic were shown to form ephemeral spawning aggregations in which actively spawning females separated spatially from the remaining population, taking with them a large proportion of males. These aggregations were shown to take place at depth; specifically, bathymetric positioning of reproductively active individuals changed during the spawning cycle in such a way that imminent spawners were located at greater depths compared to recent spawners or non-spawning females. This pattern of bathymetric segregation of sardine spawning stages is in agreement with previously published evidence that sardines spawn at depth, either from indirect acoustic sampling data or from the occurrence of early embryonic stages at greater depths. A number of physiological mechanisms that may explain changes in the bathymetric positioning of actively spawning individuals are also suggested. KEY WORDS: Spawning aggregations · Reproductive behavior · Spawning frequency · Sardine · AtlanticResale or republication not permitted without written consent of the publisher

show abstract

Physiological factors causing natural variations in acoustic target strength of fish

Cited by 231 publications

References 16 publications

Determining the target strength bambood wrasse (Pseudolabrus japonicus) using Kirchhoff-ray mode

Determining the target strength bambood wrasse (Pseudolabrus japonicus) using Kirchhoff-ray mode

Seasonal Estimates of Fish Biomass and Length Distributions Using Acoustics and Traditional Nets to Identify Estuarine Habitat Preferences in Barataria Bay, Louisiana

Bathymetric segregation of spawning stages in the Atlantic sardine Sardina pilchardus

Contact Info

Product

Resources

About