Bulletin of the Japanese Society of Fisheries Oceanography
Online ISSN : 2435-2888
Print ISSN : 0916-1562
Volume 81 , Issue 4
Showing 1-3 articles out of 3 articles from the selected issue
Original Papers
  • Akihiko YATSU, Atsushi KAWABATA
    2017 Volume 81 Issue 4 Pages 271-280
    Published: November 10, 2017
    Released: February 26, 2021
    JOURNALS FREE ACCESS

    The causes of Trans-Pacific synchrony and asynchrony in sardine populations were evaluated by examining commercial catch, fishing mortality, spawning stock biomass, and productivity, defined as ln-transformed recruitment residuals (LNRR). Anomalies of basin-scale and regional sea-surface temperatures (SSTs) are key environmental drivers of population dynamics of some stocks of sardines. Key results were: 1) productivity was synchronized between the Humboldt sardine (Sardinops sagax sagax) and the Japanese sardine (S. melanostictus) (Pacific stock) during the period for which data were available (1970–99), 2) sudden recoveries in recruitment and productivity of the Humboldt and Japanese sardines during the early 1970s were associated with favorable regional SST anomalies that were enhanced under the favorable PDO regime that followed after 1977, 3) recruitment failures coincided with a climate regime shift in 1988/89 (Humboldt and Japanese sardines and probably California sardine (S. sagax caeruleus) in the Gulf of California) and negative anomalies of PDO and CalCOFI SST during 2008–12 (the northern subpopulation of California sardine) caused natural stock declines, and 4) high fishing mortalities coupled with generally unfavorable regional SST anomalies during the 1990s and 2000s prevented recoveries of the Humboldt and Japanese sardines, under a generally favorable PDO regime for sardines. Finally, implications for fisheries management, such as longterm management coping with mismatch between economic and ecological scales of variability, were discussed.

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  • Hiroaki OMI, Masaki SANO, Takayuki KUSAKABE
    2017 Volume 81 Issue 4 Pages 284-292
    Published: November 10, 2017
    Released: February 26, 2021
    JOURNALS FREE ACCESS

    Morphology and distribution of juveniles of cynoglossid fishes were investigated in Osaka Bay during August–October in 2012–2014. Three cynoglossid (Cynoglossus robustus, C. joyneri and C. interruptus) juveniles were collected by a sledge net. C. robustus were distinguished from the other two species by the number of dorsal and anal fin rays. C. joyneri and C. interruptus have similar numbers of dorsal and anal fin rays, but could be distinguished by the relative position of the left eye and the mouth, the pigmentation pattern of the ocular side, and left eye diameter. From the minimum observed standard length at metamorphosis in each species, (C. robustus 9.6 mmSL, C. joyneri 7.2 mmSL, C. interruptus 11.0 mmSL) it was inferred that C. joyneri completed metamorphosis at a smaller size (<10 mmSL) than the other two species. Patterns of distribution of the three cynoglossid juveniles differed: C. robustus mainly at 20–30 m depth in the middle of Osaka Bay in August and September, C. joyneri mainly at 10–20 m depth in the northern part of Osaka Bay in October, C. interruptus widely distributed at 10–30 m depth in Osaka Bay mainly in October.

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  • Juri HORI, Izumi TSURITA, Hidetomo TAJIMA, Mitsutaku MAKINO
    2017 Volume 81 Issue 4 Pages 293-299
    Published: November 10, 2017
    Released: February 26, 2021
    JOURNALS FREE ACCESS

    In order to visualize the structure of human well-being derived from the marine ecosystem services of coastal areas, a comparative analysis was conducted between two region (Hinase, Okayama and Ishigaki, Okinawa) where different utilization patterns of the ecosystem services are expected. Satisfaction level and interactions of the five components of human well-being (Security, Basic materials for a good life, Health, Good social relations, and Freedom of choice and action), as defined by the Millennium Ecosystem Assessment of the United Nations, were investigated based on a questionnaire survey. Structure Equation Modeling (SEM) analysis demonstrated a common hierarchical structure of human well-being in two regions. The SEM analysis showed that the satisfaction level for ‘Security’ and ‘Basic materials for a good life’ worked as explanatory variables among five components, affecting ‘Freedom of choice and action’ as dependent variables through the effects on ‘Health’ and ‘Good social relations’ as intermediate variables in both regions. However, the intensities of the interactions among five components differed between the two regions. In Hinase, a significant effect on ‘Health’ consequently affected satisfaction with ‘Security’ which in turn increased ‘Freedom of choice and action’. In contrast, in Ishigaki, a significant effect on ‘Good social relations’ affected satisfaction with ‘Basic materials for a good life’ which in turn increased ‘Freedom of choice and action’. These results suggest that the differences observed in the structure of human wellbeing originate from the different utilization patterns of the marine ecosystem services between the two regions.

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