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Kidokoro H.,Japan National Research Institute of Fisheries And Environment of Inland Sea | Shikata T.,Ishikawa Prefecture Fisheries Research Center | Kitagawa S.,Toyama Prefecture Fisheries Research Institute
Hidrobiologica | Year: 2014

The distribution of juveniles of Japanese common squid (Todarodes pacificus) autumn cohort and its relation to oceanographic conditions were analyzed to see if they can be used to accurately forecast the stock size. Research cruises was conducted using a total of 5 research vessels during 2001-2010 in April in the southern Sea of Japan. Juveniles were caught in 267 of 331 tows of a trawl net at approximately 0-10 m depth, and the numbers caught in each tow ranged from 0 to 1087. Samples were divided into the autumn and winter cohorts based on the dorsal mantle length (DML). The autumn cohort was abundant (40 inds / tow) where the sea surface temperature ranged from 10 to 11 °C and less abundant in warmer water. This cohort was more abundant in offshore areas, while the winter cohort was more abundant near shore. The mean catch of the autumn cohort was used as an index of the annual abundance of juveniles. This index and the stock size were significantly correlated. These results suggest that the stock size of the T. pacificus autumn cohort can be forecasted before the fishing season based on the abundance of juveniles, but this relationship is highly uncertain due to observational errors. Source

Fukudome K.-I.,Japan National Research Institute of Fisheries And Environment of Inland Sea | Igeta Y.,Japan National Research Institute of Fisheries And Environment of Inland Sea | Senjyu T.,Kyushu University | Okei N.,Ishikawa Prefecture Fisheries Research Center | Watanabe T.,Japan National Research Institute of Fisheries And Environment of Inland Sea
Continental Shelf Research | Year: 2016

Spatiotemporal current variations of coastal-trapped waves (CTWs) were investigated by using a current dataset obtained from daily fishing operations west of the Noto Peninsula (NTP), Japan. Cross-shore lines located in southern, middle, and northern parts of the west coast of the NTP were designed to detect characteristics of CTWs with a time interval of a few days and about 5-km resolution in the cross-shore direction. Accuracy validation by using moored current meter data and sea level data demonstrated that the established dataset expresses accurate variations with periods of several days. The generation and propagation of a CTW event associated with a low-pressure zone passing north of the study area in late May 2010 were analyzed. Along-shore currents with the coast on the right strengthened in every line simultaneously with the domination of the southerly wind, and then weakened in order from south to north simultaneously with weakening of the southerly wind. Although the along-shore currents of the CTWs linearly decreased heading offshore along the south and middle lines, these currents broadened within about 50 km from the coast along the north line, with small variations in the cross-shelf direction, with an increase in shelf width. These generation, propagation and current structure characteristics are clarified and interpreted by the characteristics of the estimated possible CTWs west of the NTP and numerical experiments, which reproduce wind-induced freely propagating CTWs. A change in the propagation characteristics and the structure of the CTWs associated with bottom topography indicates the possibility that adjustments can occur on the order of a few dozen kilometers. © 2016 Elsevier Ltd. Source

Kuda T.,Tokyo University of Marine Science and Technology | Kaneko N.,Ishikawa Prefectural University | Yano T.,Ishikawa Prefectural University | Mori M.,Ishikawa Prefecture Fisheries Research Center
Food Chemistry | Year: 2010

Aji-narezushi (salted and fermented horse mackerel with rice) and kaburazushi (salted and fermented turnip with yellowtail and malted rice) are traditional lactic acid-fermented foods in Japan. In this study, we screened lactose utilizable, acidophilic and antioxidative lactic acid bacteria (LAB) from aji-narezushi and kaburazushi for use as a starter of various fermented foods, as well as for probiotics. Of the 177 LAB isolated strains, 57 strains fermented lactose and among these, 28 grew in MRS broth adjusted to pH 4.5. All of these 28 strains were lactobacilli and produced lactic acid in 50% Japanese white radish (daikon) juice at 15 °C. The fermented daikon juice increased the superoxide radical (O2 -) scavenging capacity, but did not change clearly the DPPH- scavenging capacity and ferrous reducing power. The O2 - scavenging activity component was fractionated to <5 kDa by ultrafiltration. Three selected strains (two from aji-narezushi and three from kaburazushi) that showed high scavenging activity are identified to Lactobacillus plantarum by 16S rRNA sequence identity and carbohydrate utilization test (API-CHL50). These L. plantarum strains could ferment milk at 42 °C, like yogurt starters, and the O2 - scavenging activity was increased by fermentation. These results suggest that the L. plantarum strains can be used as profitable starter organisms and probiotics. © 2009 Elsevier Ltd. All rights reserved. Source

Shozen K.-I.,Forestry and Fisheries Research Center | Mori M.,Ishikawa Prefecture Fisheries Research Center | Harada Y.,Forestry and Fisheries Research Center | Yokoi K.,Forestry and Fisheries Research Center | And 2 more authors.
Nippon Shokuhin Kagaku Kogaku Kaishi | Year: 2012

The aim of this study is to investigate the use of bentonite to control histamine (Hm) in commercial fish sauce and model fish sauce. Addition of bentonite at 0.1 to 30% (w/v) to commercial fish sauce resulted in an increase in Hm adherence and adsorption followed by increasing amount of additive bentonite. In the commercial fish sauce, the adhered and absorbed Hm content began to increase immediately after the addition of bentonite, and equilibrium was not attained for Hm adherence and adsorption for about 3 h. The effect of temperature (10-100°C), pH (2.0-8.0) and NaCl concentration (5-25%) on Hm adherence and adsorption in model fish sauce with bentonite was investigated. The lower the temperature and pH, the higher the Hm adherence and adsorption. However, there was no significant difference (p>0.05) in the adhered and adsorbed Hm content in the range of 5 to 25% NaCl. These results suggest that Hm level in fish sauce can be effectively reduced with bentonite. Source

Shikata T.,Ishikawa Prefecture Fisheries Research Center | Mochihira J.,Ishikawa Prefecture Fisheries Research Center | Miki T.,Towa Denki Seisakusho Co. | Watanabe T.,Japan National Research Institute of Fisheries Engineering
Nippon Suisan Gakkaishi (Japanese Edition) | Year: 2014

The behavior of Japanese common squid Todarodes pacificus around a squid jigging boat during night-time operation was investigated. Eighty-nine operations were conducted by R/V Hakusan-Maru (167 gross tons) equipped with 78 metal halide lamps (234 kW in total) in offshore fishing grounds in the Sea of Japan, and sonar images and squid catch were continuously recorded (logged). The positions of squid schools before they were caught were tracked from sonar image recordings using digitizer software. Squid schools moved around the boat, gradually approached the boat and then tended to locate in fore and aft areas just before they were caught. More squid were caught by jigging machines near the bow or stern than by those near the center of the boat. Underwater irradiance was lower in fore and aft areas than in port and starboard areas. These results indicate that squid schools tended to enter under the boat through fore and aft areas. Namely, fore and aft areas with low irradiance are thought to function as an entrance to the shaded area under the boat for the squid. Source

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