NIPPON SUISAN GAKKAISHI
Online ISSN : 1349-998X
Print ISSN : 0021-5392
ISSN-L : 0021-5392
Search
Advanced search
OR
Browse
Search
Volume 81, Issue 1
Displaying 1-34 of 34 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Foreword
Originals
  • Pacific saury fishing forecasting by using random forest
    SHINYA BABA, TAKASHI MATSUISHI
    2015 Volume 81 Issue 1 Pages 2-9
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.2
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      In Japan, Pacific saury fishing forecasts are indispensable information for fisheries. In this study, the abundance of Pacific saury in fishing grounds was predicted by using random forest and the forecast was evaluated by the Monte Carlo re-sampling method. A Pacific saury abundance index with three categories was used for the response variables. A total of 186 explanatory variables from 22 indices of marine environments from 1972 to 2011 were used. After variable selection by random forest, only four kinds of variable were chosen as explanatory variables. The hitting ratio became approximately 62% and exceeded the accuracy of present posted forecasts. By using random forest, the explanatory variables can be compressed and accurate forecasts can be made by using many explanatory variables.
    View full abstract
    Download PDF (889K)
  • Fish behavior around a trap-net with the leader-net lit by a low-power underwater lamp
    DAISAKU MASUDA, MASAHIRO MAEDA, SHUYA KAI, YOSHIHARU SASAMOTO, YOICHI ...
    2015 Volume 81 Issue 1 Pages 10-16
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.10
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      A 55 W underwater discharge lamp was set in front of the leader-net of a trap-net in Hirado Island, Nagasaki. The light was left on for 4 hours during the nighttime. We observed fish schools around the trap-net by using a scanning sonar. Fish schools were frequently observed around the lamp when lit and tended to move to the entrance of the trap-net when the lamp was turned off. We also released tagged jack mackerels before, during and after illumination from three locations in front of the leader-net to assess the effect of illumination on the catch performance of the trap-net. The recapture rate of the jack mackerels during illumination was higher than that during other time periods. Thus, the underwater illumination helps by making fish remain around the trap-net and consequently improving the catch performance of trap-net fishing.
    View full abstract
    Download PDF (1357K)
  • Estimate of number of Honmoroko Gnathopogon caerulescens caught by recreational anglers around Ibanaiko Lagoon, adjacent to Lake Biwa
    TAKESHI KIKKO, TOSHIHIDE KITAKADO, DAISUKE ISHIZAKI, MUNEJI UJIIE, NOR ...
    2015 Volume 81 Issue 1 Pages 17-26
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.17
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      To estimate the catch of Honmoroko Gnathopogon caerulescens by recreational anglers around Ibanaiko lagoon, which is adjacent to Laka Biwa, for effective fisheries management, we randomly interviewed anglers from March to May 2012 and 2013. The number of Honmoroko caught by anglers was estimated using a two-stage sampling design; fishing days were samples for the first stage, anglers for the second stage, and we conducted a creel census of anglers. The estimated number of Honmoroko caught by anglers around Ibanaiko Lagoon was 272,275 (coefficient of variation=14%) in 2012 and 85,489 (CV=13%) in 2013. This study yielded useful information for the assessment and management of Honmoroko in Lake Biwa.
    View full abstract
    Download PDF (1380K)
  • Seasonal migration of North Pacific giant octopus Enteroctopus dofleini in the Soya/La Pérouse Strait
    MINORU SANO, TADAO BANDO
    2015 Volume 81 Issue 1 Pages 27-42
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.27
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      The seasonal migration of North Pacific giant octopus Enteroctopus dofleini in the Soya/La Pérouse Strait was investigated using GPS location information of octopus catches by drift fishery boats. Body weight and stage of maturity of the collected octopuses were recorded. Immature octopuses were found at depths of 40 to 60 m in summer and 10 to 30 m in autumn to spring. Although mature octopuses were observed at the same depths as juveniles in most months, in June and July, mature males and females migrated to deeper areas immediately before death and spawning, respectively. Based on bottom water temperatures in areas where the octopus was distributed, it appears that this species migrates to deeper areas to avoid water temperatures above 18℃.
    View full abstract
    Download PDF (5316K)
  • Species composition of crabs and change in abundance of portunid crabs in the East China Sea and the Yellow Sea from the 1990s to 2000s
    KEISUKE YAMAMOTO, KAZUYA NAGASAWA
    2015 Volume 81 Issue 1 Pages 43-51
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.43
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      Both the East China Sea (ECS) and the Yellow Sea (YS) are important fishing grounds for demersal fishes and macroinvertebrates. Trawl surveys were conducted during winter to clarify the species composition of crabs and describe changes in abundance of portunid crabs in ECS in 1991-2007 and in YS in 1991-1996 with the exception of several years. In total, 34 and 11 species of crabs were collected in ECS and YS, respectively. Species richness of portunid crabs decreased in both seas. Densities of portunid crabs decreased from 686 inds./km2 in 1992 to 32 inds./km2 in 1996 in YS. However, their densities fluctuated annually between 290 and 1,807 inds./km2 and did not decline in 1991-2007 in ECS. Ovalipes punctatus was the most predominant species with its relative dominance in density of portunid crabs increasing from 76% to 98% in 1991-2007 in ECS and from 56% to 100% in 1991-1996 in YS. This predominance of O. punctatus in ECS is likely to have been caused by the decline of predators due to high fishing pressure and the occurrence of its adults in offshore waters with less fishing pressure than in coastal waters.
    View full abstract
    Download PDF (2075K)
  • Onset of individual growth difference and its hereditary factors from broodstocks in larviculture of leopard coral grouper Plectropomus leopardus
    TAKAYUKI TAKEBE, SUSUMU UJI, AKIYUKI OZAKI, KOICHI OKUZAWA, HIDEAKI YA ...
    2015 Volume 81 Issue 1 Pages 52-61
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.52
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      We conducted a rearing experiment of leopard coral grouper (LCG) Plectropomus leopardus larvae, and determined the growth history of larvae in order to clarify when the growth difference occurs. We also examined whether hereditary factors from broodstocks affect the growth difference of larvae. The otolith microstructure of LCG larvae was investigated to examine the individual growth history and to predict the age and body size at onset of individual growth difference. Since the total length (TL) of fish can be back-calculated from otolith radius (OR), we backc-alculated TLs of 50 fish at 50 days post hatching (dph) divided into three size groups (small, intermediate, large). Growth difference was recognized from 24 dph coinciding with the conversion of feeding regime, and the difference became larger thereafter. Growth difference was assumed to be promoted by completion of metamorphosis of LCG larvae. Furthermore, chi-square randomization tests (Monte Carlo Technique) of genotype variation for the three size groups of 50 dph suggested that the hereditary influence from the broodstocks on the growth difference was not significant.
    View full abstract
    Download PDF (1456K)
  • Initial food of freshwater clam Corbicula sandai and suitable diet size
    MASATAKA HATANO, DAISUKE ISHIZAKI, HIROTO KUME, KAZUTAKA SAKIYAMA
    2015 Volume 81 Issue 1 Pages 62-67
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.62
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      We investigated the growth and survival rate as well as the size composition of stomach contents of newly hatched plantigrade of Corbicula sandai by feeding 3 species of micro alga (Chlorella homosphaera, C. vulgaris, Skeletonema potamos). The highest survival rate was for C. homosphaera, while C. homosphaera and C. vulgaris supported high growth rates. It was found that newly hatched plantigrade could ingest only C. homosphaera, but based on the size composition of stomach content, with growth larger dietary species (C. vulgaris and S. potamos) could be eaten.
    View full abstract
    Download PDF (786K)
  • Zoning of Osaka Bay based on principal component analysis of sediment parameters and comparison between the 2013 and previous surveys
    HISASHI YOKOYAMA, MASAKI SANO
    2015 Volume 81 Issue 1 Pages 68-80
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.68
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      In order to clarify the spatial and temporal variations of the bottom environments in Osaka Bay, surface sediments (0-1 cm) were collected at 31 stations in August, 2013. Physico-chemical parameters of the sediment such as grain size distribution, TOC, TN, δ13C, δ15N and AVS were analyzed and DO from the bottom of the sea was measured at the sediment sampling stations. The survey yielded the following results: (1) Five zones were recognized based on the principal component analysis of nine sediment parameters; (2) sedimentary organic matter at all stations, except for stations located along the coast in the innermost part of the bay, was mainly composed of autochthonous marine organic matter (>80%); (3) there was no noticeable change in the area where high contents of TOC, TN and AVS were found; and (4) a drastic decrease in the grain size was observed in the north of Kitan Channel.
    View full abstract
    Download PDF (5108K)
  • Development of a soil bioreactor for efficiently degrading organic matter
    WEN LIU, YUTA NISHIGAITO, YOSHIYUKI ARAKI, XUEGUANG LI, TETSUHIRO WATA ...
    2015 Volume 81 Issue 1 Pages 81-89
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.81
    JOURNAL FREE ACCESS
    Supplementary material
    Show abstractHide abstract
      Amylase and protease-producing bacteria isolated from gapi (a traditional fermented Thai food) were used to develop an efficient bioreactor by immobilizing their enzymes with various soils and filter materials. The bioreactor would efficiently degrade excess organic matter originating from overloaded food in culture ponds, thereby improving water quality. Amylase- and protease-producing bacteria were detected in all gapi samples tested. The enzyme extract of gapi was immobilized with soils and filter materials to compare the ability to adsorb these materials. As a result, the amylase and protease adsorption ability significantly differed among the soils and filter materials. In particular, soil collected from Shibecha (Hokkaido) demonstrated a high ability to adsorb amylase and protease of gapi. This ability was possibly ascribed to the high concentration of amorphous aluminum according to an analysis of soil components. Therefore, aluminum oxide was tested as a candidate immobilization carrier for the bioreactor and was found to have high ability to adsorb amylase and protease of gapi as expected. These results suggest that a bioreactor that can efficiently degrade organic matter in culture ponds could be developed by immobilizing gapi enzymes with soils with a high content of amorphous aluminum or pure aluminum oxide.
    View full abstract
    Download PDF (962K)
  • Modeling of competitive adsorption process for removing cadmium from squid viscera
    HIDESHI SEKI, HIDEO MARUYAMA, MASAO KAWABE
    2015 Volume 81 Issue 1 Pages 90-96
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.90
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      A model for the system design and optimum operation control of our system for removing cadmium from squid viscera by means of the competitive adsorption method is proposed. The adsorption and desorption data of cadmium on chelating resin and squid viscera fit an ion exchange model. However, in the competitive adsorption process, the cadmium adsorption constant of the chelating resin was significantly lowered by divalent metals contained in squid viscera. The competitive adsorption model was derived by correcting the cadmium adsorption constant as a function of the solid concentration of squid viscera. The model could determine the optimum dosage of chelating resin corresponding to the cadmium content and water content of squid viscera.
    View full abstract
    Download PDF (1097K)
  • Isolation and identification of the causative bacterium of histamine accumulation during fish sauce fermentation and the suppression effect of inoculation with starter culture of lactic acid bacterium on the histamine accumulation in fish sauce processing
    MEIKO KIMURA, AYUMI FURUTANI, YOUHEI FUKUI, YUKI SHIBATA, DAISUKE NEI, ...
    2015 Volume 81 Issue 1 Pages 97-106
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.97
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      A total of 12 strains of histamine-producing bacteria harboring a pyruvoyl-dependent histidine decarboxylase gene, identified as Tetragenococcus halophilus, were isolated from a fish sauce mash accumulating over 40 mg/100 g of histamine. To confirm that the strain can produce histamine in fish sauce mashes, the representative histamine-producing strain, FS-4, was inoculated into a fish sauce mash. The histamine content of the fish sauce mash inoculated with FS-4 accumulated over 100 mg/100 g of histamine after 7 days at 30℃. In contrast, histamine accumulation was not observed in sterile fish sauce mashes irradiated with over 10.0 kGy of gamma-rays, indicating that the causative agent of histamine accumulation in fish sauce mashes was microorganisms. The addition of starter culture consisting of T. halophilus NBRC12172 (isolated from soy sauce mash), which does not harbor the histidine decarboxylase gene, to the fish sauce mashes effectively suppressed histamine accumulation. According to the result of a competitive growth test between strain FS-4 and starter culture in fish sauce mashes, it is necessary to suppress histamine accumulation during fish sauce fermentation by adding to fish sauce mashes a starter culture with a total biomass more than one thousand times that of the histamine-producing bacterial cells.
    View full abstract
    Download PDF (1558K)
  • The relationships between nutrient concentration in the coastal area of Okayama prefecture, the color tone of fresh thalli (Pyropia) and the unit price of dried nori
    FUMIYASU MURAYAMA, YASUKO SHIMIZU, SHUZO TAKAGI
    2015 Volume 81 Issue 1 Pages 107-114
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.107
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      The relationships between the nutrient concentration in the seawater, the color tones (L∗ and a∗ values) of fresh thalli and dried nori using a color difference meter, and the unit prices of dried nori were investigated in the coastal area of Okayama prefecture. The limiting factor for discoloration of nori in this ocean area was dissolved inorganic nitrogen (DIN). If its concentration fell to 3 μM or below, the color tone of fresh thalli was found to deteriorate sharply. Close correlations were observed between the DIN concentration (a) and fresh thalli L∗ (b) and a∗ values (b′) (b=−7.7 log (a)+64.1 and b′=3.0 log (a)+2.2); between fresh thalli L∗ and a∗ values and dried nori L∗ values (c) (c=11.5e0.01b and c=34.4e−0.04b′); and between dried nori L∗ values and unit prices of dried nori in 2011 (z1), in 2012 (z2) (z1=4.2×103×c−1.8 and z2=9.6×102×c−1.7).
    View full abstract
    Download PDF (2099K)
  • Changes in lipid characteristics of mullet Mugil cephalus roe during processing to Karasumi product
    DAISUKE ITO, KIGEN TAKAHASHI, EMIKO OKAZAKI, ASADA JIARPINIJNUN, HIROA ...
    2015 Volume 81 Issue 1 Pages 115-123
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.115
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      The changes in lipid characteristics of mullet Mugil cephalus roe during processing to Karasumi product were investigated. The Karasumi was prepared according to the conventional process of salting, desalting, and sun-drying. The unprocessed roe contained wax esters (WE), triacylglycerols (TAG), free fatty acids (FFA), and phosphatidylcholines (PC) as major lipids, which accounted for 69.2, 13.2, 4.0, and 5.6% of total lipids, respectively. WE contained saturated fatty alcohols and monoenoic and polyenoic fatty acids as main components, whereas saturated fatty acids and monoenoic fatty acids were dominant in TAG. The WE level and its fatty alcohol composition and fatty acid composition did not show significant changes during the whole process. The level of TAG showed a slight decrease during the sun-drying process, while no changes were observed in its fatty acid composition. The FFA level, especially the free-total saturated fatty acids level, increased during the whole process, indicating that FFA were mainly supplied from degradation of TAG during the processing. There were no statistical changes in PC level or its fatty acid composition. These results suggest that the lipid profiles of mullet roe remain unchanged during processing to Karasumi product, compared with other dried seafood products.
    View full abstract
    Download PDF (382K)
  • Effects of freshness on thawing drip and ice crystal formation in frozen spotted mackerel Scomber australasicus
    KANAKO HASHIMOTO, TOKIFUSA KAWASHIMA, NOBUYUKI YOSHINO, TAKAAKI SHIRAI ...
    2015 Volume 81 Issue 1 Pages 124-129
    Published: 2015
    Released on J-STAGE: February 02, 2015
    DOIhttps://doi.org/10.2331/suisan.81.124
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      The effects of freezing and thawing on the meat of spotted mackerel Scomber australasicus were studied. The fish meat was kept in iced water for different time intervals before being frozen at −20℃ for one month. The ice crystals in muscle tissue of fish meat stored in iced water for a short time (pre-rigor mortis) before being frozen were small and were observed mainly in the intracellular spaces, while those of the fish kept for a long time (post-rigor mortis) before being frozen, e.g. for 4 days, were large and were observed mostly around the connective tissues. The amount of thawing drip of the latter was larger than that of the former. In this drip free amino acid, probably derived from decomposition of the protein, was detected. These findings suggest that the protein degrades along with the decline in freshness, and that the degraded tissue causes the formation of large ice crystals, resulting in a large amount of thawing drip. This phenomenon may be one of the dominant factors causing the deterioration in quality of frozen spotted mackerel.
    View full abstract
    Download PDF (1556K)
Short Paper
Mini-Symposium
Creation of cephalopodology with direction of fundamental research applicable for fisheries science
News
Highlights in Fisheries Science Research
Topics
Dynamic Women@Fisheries Science 27
Abstracts of Original Papers
Errata
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top