In situ broadband acoustic measurements of age-0 walleye pollock and pointhead flounder in Funka Bay, Hokkaido, Japan

Abstract Acoustic measurements at 1.5–5 kHz on fish in the Gulf of Maine showed a swimbladder-resonance peak near 2.5 kHz at 160–190-m depth. Midwater trawls confirmed that the fish were likely to be Atlantic herring (Clupea harengus) of 19–29 cm length. Calculation using a model of swimbladder resonance gives swimbladder volumes of 1.2% of fish weight at 160–190 m. Extrapolation of this volume of gas using Boyle's Law suggests that at the sea surface, these herring would need to inflate their swimbladders by up to five to six times the volume required for neutral buoyancy. If these fish were to maintain this volume of gas with surface “gulping”, they would need to submerge from the sea surface with a 30% excess buoyancy. In general, swimbladders of the Clupeidae may have greater volumes of gas than if the fish were neutrally buoyant at the sea surface and the interpretation of HF-echosounder surveys may be additionally complex when the volume of gas and swimbladder volume are difficult to predict. Mechanisms of how herring obtain additional swimbladder gas are discussed.

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Comparing acoustic model estimations and in situ target strength measurements of juvenile walleye pollock (Theragra chalcogramma)

The Journal of the Acoustical Society of America ◽

10.1121/1.4787316 ◽

2006 ◽

Vol 120 (5) ◽

pp. 3060-3061

Author(s):

Kazuhiro Sadayasu ◽

Tohru Mukai ◽

Kohji Iida

Keyword(s):

Walleye Pollock ◽

Target Strength ◽

Theragra Chalcogramma ◽

Acoustic Model ◽

Walleye Pollock Theragra Chalcogramma

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Multifrequency target strength of northern krill (Meganyctiphanes norvegica) swimming horizontally

ICES Journal of Marine Science ◽

10.1093/icesjms/fsr170 ◽

2011 ◽

Vol 69 (1) ◽

pp. 119-130 ◽

Cited By ~ 5

Author(s):

Lucio Calise ◽

Tor Knutsen

Keyword(s):

Length Distribution ◽

Ex Situ ◽

Target Strength ◽

Acoustic Backscatter ◽

Acoustic Measurements ◽

Acoustic Beams ◽

Meganyctiphanes Norvegica ◽

Acoustic Identification ◽

Made In

Abstract Calise, L., and Knutsen, T. 2012. Multifrequency target strength of northern krill (Meganyctiphanes norvegica) swimming horizontally. – ICES Journal of Marine Science, 69: 119–130. Multifrequency acoustic measurements on ex situ horizontally swimming krill were made in a novel experimental setting. An ensemble of northern krill (Meganyctiphanes norvegica) was introduced to a large enclosure (a mesocosm), and acoustic backscatter was sampled using a multifrequency (70, 120, and 200 kHz) echosounder (Simrad EK60). Two submerged lamps were placed at opposite sides of the mesocosm and switched on and off to induce the krill, by light attraction, to swim horizontally through the acoustic beams. By tracking echoes, animal displacement, swimming speed, and target strength (TS) by frequency were estimated. The dominant and secondary modes of the total-length distribution were 21.8 ± 3.0 and 27.8 ± 2.7 mm, respectively. Although krill orientation was assumed stable and the ping rate was high, the range and inter-ping variability of the average TS values were large, decreasing and increasing with frequency, respectively. The overall TS frequency response observed and concurrent measurements at 120 and 200 kHz confirm the theoretical expectation that the acoustic backscatter from the investigated organisms were confined to the Rayleigh and Geometric scattering regions, a finding that might both aid acoustic identification and size-group separation of in situ northern krill.

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Distribution and movement of walleye pollock larvae Theragra chalcogramma in Funka Bay and the adjacent waters, Hokkaido.

NIPPON SUISAN GAKKAISHI ◽

10.2331/suisan.53.1585 ◽

1987 ◽

Vol 53 (9) ◽

pp. 1585-1591 ◽

Cited By ~ 15

Author(s):

Toshikuni Nakatani ◽

Tatsuaki Maeda

Keyword(s):

Walleye Pollock ◽

Theragra Chalcogramma ◽

Funka Bay

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Effect of environmental factors and prey species on daytime and nighttime vertical distribution of juvenile walleye pollock in and around Funka Bay

Fisheries Science ◽

10.1007/s12562-014-0718-x ◽

2014 ◽

Vol 80 (2) ◽

pp. 139-149 ◽

Cited By ~ 4

Author(s):

Yohei Kawauchi ◽

Masayuki Chimura ◽

Takashi Mutoh ◽

Masamichi Watanobe ◽

Hokuto Shirakawa ◽

...

Keyword(s):

Environmental Factors ◽

Vertical Distribution ◽

Prey Species ◽

Walleye Pollock ◽

Funka Bay

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Development of a three-dimensional growth prediction model for the Japanese scallop in Funka Bay, Japan, using OGCM and MODIS

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv153 ◽

2015 ◽

Vol 72 (9) ◽

pp. 2684-2699 ◽

Cited By ~ 4

Author(s):

Yang Liu ◽

Sei-Ichi Saitoh ◽

Yu Ihara ◽

Satoshi Nakada ◽

Makoto Kanamori ◽

...

Keyword(s):

Prediction Model ◽

Three Dimensional ◽

Temperature Data ◽

Japanese Scallop ◽

Growth Prediction ◽

Chl A ◽

Funka Bay ◽

Dimensional Growth ◽

In Situ Observations

Abstract The Japanese scallop (Patinopecten (Mizuhopecten) yessoensis) is an important commercial species in Funka Bay, Japan, where it is farmed using the hanging culture method. Our study was based on 6 years (from 2006 to 2011) of monthly in situ observations of scallop growth at Yakumo station. To produce a basic spatial distribution dataset, we developed an interpolation solution for the shortage of Chl-a concentration data available from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite. Additionally, we integrated four-dimensional variational (4D-VAR) assimilation water temperature data from ocean general circulation models (OGCMs), with four vertical levels (6, 10, 14, and 18 m) from the sea surface. Statistical models, including generalized additive models (GAMs) and generalized linear models, were applied to in situ observation data, satellite data, and 4D-VAR data to identify the influence of environment factors (interpolated Chl-a, temperature, and depth) on the growth of scallops, and to develop a three-dimensional growth prediction model for the Japanese scallops in Funka Bay. We considered three methods to simulate the growth process of scallops (accumulation, summation, and product), and used them to select the most suitable model. All the interpolated Chl-a concentrations and 4D-VAR temperature data were verified by shipboard data. The results revealed that GAM, using an accumulation method that was based on a combination of integrated temperature, integrated log Chl-a, depth, and number of days, was best able to predict the vertical and spatial growth of the Japanese scallop. The predictions were verified by in situ observations from different depths (R2 = 0.83–0.94). From the distribution of three-dimensional predicted scallop growth maps at each depth, it was suggested that the growth of the Japanese scallop was most favourable at 6 m and least favourable at 18 m, although variations occurred in each aquaculture region in different years. These variations were probably due to the ocean environment and climate variation.

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