NIPPON SUISAN GAKKAISHI
Online ISSN : 1349-998X
Print ISSN : 0021-5392
ISSN-L : 0021-5392
Current issue
Displaying 1-36 of 36 articles from this issue
Message of the President
Foreword
Technical Achievement Awards in Fisheries Science 2021
Originals
  • KOH HASEGAWA, MASATO SATO, TOSHIAKI SATO, YUTO SUZUKI, RYOSUKE YOSHIZA ...
    Article type: Originals
    2022 Volume 88 Issue 5 Pages 339-344
    Published: September 15, 2022
    Released on J-STAGE: September 29, 2022
    Advance online publication: August 06, 2022
    JOURNAL FREE ACCESS
    Supplementary material

     Since the 2000s, coastal catches of masu salmon have decreased on the Sea of Japan side of Hokkaido and Honshu but increased on the Okhotsk and Pacific sides of Hokkaido, while neither increasing nor decreasing on the Pacific side of Honshu. This result suggests that annual coastal catches are influenced by natural environmental factors which change temporally such as climate change, and that hatchery fish stocking does not significantly affect annual coastal catches. For the management of masu salmon resources, therefore, we recommend using wild fish which are subject to natural selection rather than stocking hatchery fish.

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  • EIJI TANAKA
    Article type: Originals
    2022 Volume 88 Issue 5 Pages 345-354
    Published: September 15, 2022
    Released on J-STAGE: September 29, 2022
    Advance online publication: August 10, 2022
    JOURNAL FREE ACCESS

     An age, sex and stage structured model of stock dynamics into which the effect of terminal molt of individual growth is incorporated was applied to Japanese data of the Sea of Japan stock of red snow crab in order to estimate stock sizes from 1978 to 2018. The model of the stock by sex consisted of an immature component in which growth of body length continued and a mature component in which the growth stopped by terminal molt. The data sets used for estimations were the series of catch over the years, that of abundance index, average body weight in catch over 2000-2018, series of index of body weight and some biological parameter values. Using a given fishing coefficient and stable age-composition in the first year of data, annual stock sizes in subsequent years were computed using those values, biological parameters and deterministic equations in the model. Unknown parameters were estimated using the least squares method, and the parametric bootstrap method was used to estimate variances of parameter estimates. The results of estimations showed that point estimates of spawning stock biomass in 2015 were 204 (CI: 184-224) thousand tons. Modifications and issues concerning the estimations in the future are discussed.

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  • SOICHIRO YAMAMOTO, HIROMICHI MITAMURA, KOUHEI KUROKAWA, TAKUYA KUNIMOR ...
    Article type: Originals
    2022 Volume 88 Issue 5 Pages 355-364
    Published: September 15, 2022
    Released on J-STAGE: September 29, 2022
    Advance online publication: August 20, 2022
    JOURNAL FREE ACCESS

     We released 30 adult marbled flounder Pseudopleuronectes yokohamae attached with temperature-depth data loggers off Himeshima Island at Suo Nada in the Seto Inland Sea, on July 3, 2017. Two loggers recorded data from the release day until December-January. In September, the hottest month of the year, the most frequently experienced water temperature and depth for marbled flounder were 24-25℃ (53.9-57.6%) and 0-5 m (44.3-73.9%), respectively. The experienced water temperature reached 27℃, but the proportion of the experienced water temperature over 26℃ was low at 3.9-4.5% for the two marbled flounder. We also noted vertical movements of the marbled flounder based on depth data. When marbled flounder experienced marked changes in water temperature, water depth and distribution area, they continued to move vertically. The results suggested that marbled flounder can survive in a water temperature lower than 26℃ in natural sea water. Moreover, vertical movements may be related to migration.

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  • YASUYUKI KANAMOTO, YUTA YAGI, SORATA TANAKA, MIYUKI KANAIWA, HIRONORI ...
    Article type: Originals
    2022 Volume 88 Issue 5 Pages 365-385
    Published: September 15, 2022
    Released on J-STAGE: September 29, 2022
    Advance online publication: September 02, 2022
    JOURNAL FREE ACCESS

     This study focused on blackthroat seaperch in the southwestern Japan Sea. An age-length key (ALK) was established based on transverse sections of otoliths. Catch in number by age was estimated using the ALK and catch information from Shimonoseki and Hamada fishing ports in Yamaguchi and Shimane prefectures, respectively. Standardized catch per unit effort (CPUE, kg/tow・vessel) was calculated after filtering the organized CPUE data of blackthroat seaperch from the fishery logbook data of offshore trawl fisheries. Stock in biomass, fishing mortality coefficient, and relationship between spawning stock biomass and recruitment in number were estimated using an adaptive framework virtual population analysis. A retrospective analysis confirmed the validity of the estimated results. Stock levels in biomass of blackthroat seaperch in the southwestern Japan Sea have been high and constant in recent years. We considered a management policy for protecting the small-sized blackthroat seaperch.

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  • TSUNEO MAEDA, ISAMU UCHIYAMA
    Article type: Originals
    2022 Volume 88 Issue 5 Pages 386-395
    Published: September 15, 2022
    Released on J-STAGE: September 29, 2022
    Advance online publication: August 10, 2022
    JOURNAL FREE ACCESS

     In order to clarify the growth of male beni-zuwai crab Chionoecetes japonicus, the mean carapace width at each instar was estimated by decomposing the polymodal size frequency distributions of male crabs collected from the central part of Toyama Bay at the depth of 1055-1270 m by beam trawls from 2006 to 2012 and by crab pots in 2004 and 2011. The mean sizes from the 3rd to 13th instar were estimated to be 6.3, 9.1, 12.9, 18.0, 25.5, 34.1, 44.6, 58.3, 74.0, 88.3, and 105.8 mm CW, respectively. The ratios of adult male crab with relatively large-sized chela were 2.8%, 11.4%, 34.9%, and 74.0% at the 10th to 13th instars, respectively, which indicated that the proportion of morphometrically mature male crabs increased greatly from the 12th to 13th instar.

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  • TAKASHI YANAGIMOTO, SEINEN CHOW, TAKESHI SAKAI, SHUHEI SAWAYAMA, YORIK ...
    Article type: Originals
    2022 Volume 88 Issue 5 Pages 396-406
    Published: September 15, 2022
    Released on J-STAGE: September 29, 2022
    Advance online publication: August 10, 2022
    JOURNAL FREE ACCESS
    Supplementary material

     Japanese top shell Turbo sazae were collected from 11 locations covering almost the entire distribution range in Japan, and nucleotide sequences of mitochondrial 16S rDNA and COI and shell spine types were analyzed. Nucleotide sequences were segregated into two haplogroups; the frequencies of these haplogroups substantially differed between the Japan Sea and Pacific populations. The mean nucleotide substitution rate between the haplogroups was 1.247% for 16S rDNA and 1.429% for COI. Significant genetic differentiation was also observed between local populations within each ocean basin. Large variations in the frequency of spined and spine-less types and the size of spine were observed even between close-neighboring local populations, for which environmental factors were considered to play a major role.

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Short Paper
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Nondestructive technologies for quality evaluation of seafood
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Mini-Symposium
Current status and prospects of studies on the biosynthesis and dynamics of tetrodotoxin and paralytic shellfish toxins
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