Interdecadal decrease in potential fishing areas for Pacific saury off the southeastern coast of Hokkaido,Japan          下载免费PDF全文

Hiroshi Kuroda  Katsumi Yokouchi 《Fisheries Oceanography》2017,26(4):439-454

We examined interdecadal variations in potential fishing grounds for the Pacific saury, Cololabis saira, off the southeastern coast of Hokkaido, Japan, for the early fishing season of August–September. We applied linear trend analysis to a time series of several oceanographic variables for 1993–2014. Trends in the appearance frequency of sea surface temperatures (SST) of 12–18 °C during August–September indicated an interdecadal reduction in the potential fishing area off the Hokkaido coast. There were localized significant increases of both SST and the sea level anomaly along the Kuril–Kamchatka Trench off the Hokkaido coast. The localized trends coincided with decadal decreases of satellite‐based chlorophyll concentrations after 2002. Analysis of mesoscale eddies revealed that the localized trends were related to clockwise (counterclockwise) eddies that appeared more frequently (less frequently) near the trench in recent years. Moreover, the Oyashio transport on the slope between the coast and the trench decreased significantly and completely disappeared in some recent summers. Interactions between the Oyashio and mesoscale eddies resulted in an interdecadal shift in the cold‐water intrusion along the main stream of the Oyashio from the along‐slope direction to the offshore direction in the upstream region of the Hokkaido coast, and large areas of favorable potential fishing grounds near the Hokkaido coast have disappeared in recent years.  相似文献   

Effect of dietary glucosylceramide from sea cucumber on plasma and liver lipids in cholesterol-fed mice     

Zakir Hossain  Tatsuya Sugawara  Kazuhiko Aida  Takashi Hirata 《Fisheries Science》2011,77(6):1081-1085

Various physiological functions of dietary glucosylceramides (GlcCer) have been reported, such as preventing colon cancer and improving skin barrier function. One potential GlcCer source used as a foodstuff is sea cucumber. In this study, our objective was to determine the effect of dietary GlcCer prepared from sea cucumber on plasma and liver lipids in cholesterol-fed mice. ICR mice were fed four different diets (control diet, sea cucumber GlcCer supplemented diet, high cholesterol supplemented diet, and high cholesterol + sea cucumber GlcCer supplemented diet). Dietary GlcCer decreased total cholesterol significantly in ICR mice. The mRNA expression of LDL receptor was increased significantly, while the expression of the gene CYP7A1, which is involved in bile acid formation, was decreased significantly compared with the control (diet without cholesterol). These results suggest that the expression of the cholesterol homeostasis gene in liver is modulated due to the cholesterol lowering effect of dietary GlcCer.  相似文献   

A new species of freshwater eel <Emphasis Type="Italic">Anguilla luzonensis</Emphasis> (Teleostei: Anguillidae) from Luzon Island of the Philippines     

Shun Watanabe  Jun Aoyama  Katsumi Tsukamoto 《Fisheries Science》2009,75(2):387-392

Anguilla luzonensis, a new species of freshwater eel, family Anguillidae, is described on the basis of 29 specimens collected from the Pinacanauan River system, which is a tributary of the Cagayan River on northern Luzon Island of the Philippines. The new species and A. celebesensis, which is distributed in the same region, both have variegated color marking and broad maxillary bands of teeth, but show statistically significant differences in the following characters of the new species: predorsal-fin length 28.6–33.1% of total length (TL); preanal length 39.6–44.8% of TL; trunk length 26.4–31.3% of TL; distance between the verticals through the anus and origin of the dorsal fin 9.3–13.9% of TL; length of gape 35.5–46.9% of head length; the total number of vertebrae 103–107; and number of abdominal vertebrae 40–42. These morphological differences, together with the present knowledge about anguillid eel taxonomy, genetics, and ecology, strongly support the presence of the new species A. luzonensis in the area of northern Luzon Island of the Philippines.  相似文献   

优质高产抗病小麦新品种镇麦6号的选育与栽培技术要点   总被引：1，自引：1，他引：0  

陈爱大  朱传统  岳绪国  景德道 《江苏农业科学》2006,(5):37-38

镇麦6号(原名镇99018)系江苏丘陵地区镇江农业科学研究所选育的优质高产抗病小麦新品种,2005年9月通过江苏省农作物品种审定委员会审定并定名。1选育经过1994年春,用高产稳产综合性状好的扬麦158作母本,分蘖性强易争穗、抗病性好的镇麦1号为父本,通过有性杂交,采用系谱法选育。于1997年夏收,将F3中的20株优良单株赴昆明加代,并将其中15个株系混收升级鉴定,在鉴定中有11个株系的主要农艺性状仍有分离,继续选取优良单株。1999年夏收,在F6中将综合农艺性状趋向一致的10个株系进行升级鉴定试验。其中,鉴定号为“99018”株系表现突出,提升参加本…  相似文献   

Strategies for improving fuel efficiency in the Portuguese trawl fishery     

Joaquim Parente  Paulo Fonseca  Victor Henriques  Aida Campos 《Fisheries Research》2008,93(1-2):117-124

The recent rise in oil prices has brought renewed attention to energy savings in the fishing industry, and particularly in trawling. Coastal trawlers spend most of their time on fishing grounds near the coast. In such cases, the most successful energy-saving modifications ought to result from changes in the fishing gear and towing conditions. The purpose of this study was to identify the energy-economy potential for Portuguese fish trawlers after altering a vessel's operating conditions and improving its trawl gear performance. Two trawlers, named Tricana de Aveiro and João Macedo were selected as subjects in this project. Both vessels work with gear of similar design and size. Experimental sea trials were carried out to elucidate the actual vessel and gear performance. A model trawl was then built and tested in a flume tank, which provided the basis for improving the gear design. Full-scale trials were then carried out with both vessels using the modified trawls in order to assess changes in gear performance. The new trawls maintained their previous ability to catch species of different ecological groups and consumed less fuel at the same commercial trawling speed. An economic study showed potential increases in the net cash flow (NCF) of up to 27% over the range of operational navigation and trawling speeds. Having demonstrated the performance of the new trawls, the skippers of both vessels subsequently adopted the new design for commercial fishing.  相似文献   

Phenotypic characterization and cultivation conditions of inhibitor-producing fungus isolated from marine sediment     

Katsuhisa Yamada  Chiaki Imada  Masataka Uchino  Takeshi Kobayashi  Naoko Hamada-Sato  Katsumi Takano 《Fisheries Science》2008,74(3):662-669

ABSTRACT:   Tyrosinase inhibitor-producing fungus of Trichoderma sp. strain H1-7, which was isolated from marine sediment, was investigated by phylogenetic analysis and physiological characteristics. Phylogenetic analyses of the strain were similar to Trichoderma atroviride or T. viride . Physiological characteristics of the strain were similar to T. viride , and based on these results, it was identified as T. viride . Characterization of tyrosinase inhibitory activity of a culture supernatant of the strain was investigated. The inhibitory activity of the supernatant of the strain decreased after cultivation for more than 3 days. Furthermore, sea water was not essential for the production of the tyrosinase inhibitor (TI). When TI production of the strain was compared to T. viride , the strain showed higher activity than T. viride . From this result, it seemed that the strain had characteristic features comparable to T. viride , which was isolated from the terrestrial environment. As TI production of the strain showed higher potential than that of T. viride , it is necessary to elucidate the chemical structure of TI exemplified in the present study.  相似文献   

Volatile compounds characterizing Tunisian Chemlali and Chétoui virgin olive oils     

Tena N  Lazzez A  Aparicio-Ruiz R  García-González DL 《Journal of agricultural and food chemistry》2007,55(19):7852-7858

A total of 33 virgin olive oil samples of the two main Tunisian cultivars, Chemlali and Chétoui, were characterized by their volatile compounds. The olive oil samples were obtained from olives harvested at four stages of ripeness in costal and inland farms of different geographical places. Major volatiles, mostly C6 and C5 compounds produced from linolenic and linoleic acids through the lipoxygenase cascade, were quantified by solid-phase microextraction-gas chromatography. Mathematical procedures allowed for the determination of the volatiles that not only are able to discriminate the olive oils by their olive cultivar (hexanal, E-2-hexenal, and total ketones) and ripeness (pentanal and 1-penten-3-one) but also contribute to their distinctive aroma. Finally, an electronic nose based on metal oxide sensors was checked for a rapid and at-line implementation of Tunisian olive oil varietal traceability. The classification of the samples by the sensors was explained by their sensitivity to volatiles E-2-hexanal, hexanal, 1-penten-3-one, ethanol, and Z-3-hexenol. Multivariate procedures of discriminant analysis and principal component analysis were used in the study.  相似文献