DSpace Collection: 2006-11
http://hdl.handle.net/2115/32479
2006-112024-03-28T14:35:21Zホタテ貝養殖漁船における漁労作業用係留装置の改良 : 緩衝材の利用とその効果
http://hdl.handle.net/2115/32482
Title: ホタテ貝養殖漁船における漁労作業用係留装置の改良 : 緩衝材の利用とその効果
Authors: 津村, 良祐; 木村, 暢夫; 藤森, 康澄; 岩森, 利弘
Abstract: Ship motions on the small fishing boats for scallop cultivation in Funka-Bay, Hokkaido, are usually influenced by the dynamic force of large scale cultivation facilities. On the rough sea condition, it would generate fatal ship motions like large amplitude rolling motion. To reduce such ship motions under fishing conditions, we designed a new type of mooring device with buffer materials used as absorber for ship motions. We carried out the tank experiment used the model in the wave conditions corresponded to the actual fishing operation to confirm the effect of reducing ship motion. For the waves in the long-period frequently generated under rough sea, the damping effect of the absorber was effective to reduce rolling motion, and accounting for nothing less than 10.0% compared with the normal mooring device without the absorber. As a result, the mooring device with absorber is effective for the improvement of seakeeping qualities of the fishing boats for scallop cultivation.2006-10-31T15:00:00Z津村, 良祐木村, 暢夫藤森, 康澄岩森, 利弘Ship motions on the small fishing boats for scallop cultivation in Funka-Bay, Hokkaido, are usually influenced by the dynamic force of large scale cultivation facilities. On the rough sea condition, it would generate fatal ship motions like large amplitude rolling motion. To reduce such ship motions under fishing conditions, we designed a new type of mooring device with buffer materials used as absorber for ship motions. We carried out the tank experiment used the model in the wave conditions corresponded to the actual fishing operation to confirm the effect of reducing ship motion. For the waves in the long-period frequently generated under rough sea, the damping effect of the absorber was effective to reduce rolling motion, and accounting for nothing less than 10.0% compared with the normal mooring device without the absorber. As a result, the mooring device with absorber is effective for the improvement of seakeeping qualities of the fishing boats for scallop cultivation.富山湾における数日周期の風強制流速変動
http://hdl.handle.net/2115/32481
Title: 富山湾における数日周期の風強制流速変動
Authors: 相木, 智一; 磯田, 豊; 小善, 圭一
Abstract: Two-layer current measurements were carried out at the bay-head over the shelf of the Toyama Bay,from 24 February to 13 March 2002. The upper was set at 100m and lower at 300 m below the sea surface. Current fluctuations caused by wind variation with several-day period are observed. It is found that the phase difference between upper and lower current variations shows about 90 degree. Such fluctuations cannot be explained by a single baroclinic coastal-trapped wave (out of phase) and barotropic one (in phase). So, the generation and propagation of several-day period fluctuations forced by wind were investigated by using the numerical two-layer model. In result, the observed current fluctuations can be reasonably explained by two-type coastal-trapped waves simultaneously excited mainly by north-south wind variations. One is internal Kelvin wave propagated in the upper layer with phase velocity of about 1ms-1 and the other is the bottom-trapped shelf wave slowly propagated with phase velocity of about 0.25 ms-1.2006-10-31T15:00:00Z相木, 智一磯田, 豊小善, 圭一Two-layer current measurements were carried out at the bay-head over the shelf of the Toyama Bay,from 24 February to 13 March 2002. The upper was set at 100m and lower at 300 m below the sea surface. Current fluctuations caused by wind variation with several-day period are observed. It is found that the phase difference between upper and lower current variations shows about 90 degree. Such fluctuations cannot be explained by a single baroclinic coastal-trapped wave (out of phase) and barotropic one (in phase). So, the generation and propagation of several-day period fluctuations forced by wind were investigated by using the numerical two-layer model. In result, the observed current fluctuations can be reasonably explained by two-type coastal-trapped waves simultaneously excited mainly by north-south wind variations. One is internal Kelvin wave propagated in the upper layer with phase velocity of about 1ms-1 and the other is the bottom-trapped shelf wave slowly propagated with phase velocity of about 0.25 ms-1.Molecular Phylogenetic Analysis of Euphausia pacifica, Thysanoessa longipes and T. inermis (Crustacea : Euphausiacea) in the Subarctic Pacific Region, with Notes on Non-Geographical Genetic Variations for E. pacifica
http://hdl.handle.net/2115/32480
Title: Molecular Phylogenetic Analysis of Euphausia pacifica, Thysanoessa longipes and T. inermis (Crustacea : Euphausiacea) in the Subarctic Pacific Region, with Notes on Non-Geographical Genetic Variations for E. pacifica
Authors: Takahashi, Tomokazu; Taniguchi, Marina; Sawabe, Tomoo; Christen, Richard; Ikeda, Tsutomu
Abstract: Nucleotide sequences of a 1,854 base pair region of the nuclear small subunit(18S)rDNA gene and of a 475 or 476 base pair region of the mitochondrial large subunit(mt16S)rRNA gene were determined for Euphausia pacifica collected from the western/eastern subarctic Pacific,Okhotsk Sea and Japan Sea, and Thysanoessa inermis from the Okhotsk Sea T.inermis from the Okhotsk Sea and Bering Sea. Interspecific differences were 0.16-0.86% for 18S rDNA gene and 2.3-9.3%for 16S rRNA gene. Intraspefic differences are of special interest of E.pacifica from geographically distant sites,but were very small(0.0-<0.1%for 18S rDNA, and 0.0-0.4%for 16S rRNA). The lack of the regional haplotype structure in E.pacifica suggests significant gene flow mediated by the ocean-scale circulation system for those living in the west-east subarctic Pacific and Bering Sea. For the Japan Sea population which has been isolated from populations in the Subarctic Current originating 8,000 years ago,the time scale is considered to be not long enough to observe variations. On the basis of phylogenetic trees established,the position of the three euphausiids was briefly discussed.2006-10-31T15:00:00ZTakahashi, TomokazuTaniguchi, MarinaSawabe, TomooChristen, RichardIkeda, TsutomuNucleotide sequences of a 1,854 base pair region of the nuclear small subunit(18S)rDNA gene and of a 475 or 476 base pair region of the mitochondrial large subunit(mt16S)rRNA gene were determined for Euphausia pacifica collected from the western/eastern subarctic Pacific,Okhotsk Sea and Japan Sea, and Thysanoessa inermis from the Okhotsk Sea T.inermis from the Okhotsk Sea and Bering Sea. Interspecific differences were 0.16-0.86% for 18S rDNA gene and 2.3-9.3%for 16S rRNA gene. Intraspefic differences are of special interest of E.pacifica from geographically distant sites,but were very small(0.0-<0.1%for 18S rDNA, and 0.0-0.4%for 16S rRNA). The lack of the regional haplotype structure in E.pacifica suggests significant gene flow mediated by the ocean-scale circulation system for those living in the west-east subarctic Pacific and Bering Sea. For the Japan Sea population which has been isolated from populations in the Subarctic Current originating 8,000 years ago,the time scale is considered to be not long enough to observe variations. On the basis of phylogenetic trees established,the position of the three euphausiids was briefly discussed.