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浅海域における海況変動と漁況に関する研究
https://fra.repo.nii.ac.jp/records/2011490
https://fra.repo.nii.ac.jp/records/20114901109c981-e727-4d9a-a812-8e2bb64957a2
| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2024-10-11 | |||||
| タイトル | ||||||
| タイトル | 浅海域における海況変動と漁況に関する研究 | |||||
| 言語 | ja | |||||
| タイトル | ||||||
| タイトル | Studies on the characteristics of oceanographic condition in relation to fishing condition in the shallow coastal waters | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | jpn | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | departmental bulletin paper | |||||
| アクセス権 | ||||||
| アクセス権 | open access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||
| 著者 |
俵, 悟
× 俵, 悟 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The major aim of the present study was to find out a new method of the catch prediction by analysing the catch statistics, oceanographic and weather data in the shallow coastal waters. Therefore, the characteristics of seasonal changes of constant flow and oceanographic structure were studied, using the available data in the Seto Inland Sea. In summer, in the layer shallower than 5 m, the westward current which had mean velocity of 1-3 cm/s was recognized in the western region of Bisan Seto. And in the eastern region of Bisan Seto the eastward current with mean velocity of 2-3 cm/s was recognized. Further, in the layer deeper than 10 m or in the bottom layer, the eastward current existed in the western region of Bisan Seto and the westward current existed from the eastern region of Bisan Seto to western region of Harima Nada. From these facts, it is suggested that the gravitational circulations due to density current should be formed in both regions of Bisan Seto and come into contact with each other near Bisan Seto. In the region from Bisan Seto to Harima Nada, eastward current was stronger in winter than in summer and its velocity was about 5 cm/s in the eastern region of Harima Nada. In the region from Bingo Nada to Iyo Nada, westward current velocity tended to become smaller than 1 cm/s, but a little different current pattern was seen in summer. These suggest that a constant flow pattern in summer is not the same as that in winter, because in summer the density current develops due to the increase of discharged water from rivers and in winter the wind driven current develops due to monsoon. Sea surface water temperature in the western region tends to be higher than that of the eastern region in winter, and vice versa in summer. The yearly means of sea surface temperature of Bungo strait, Iyo Nada and Kii strait near open sea, are higher than inner region. Annual ranges of temperature in the same regions are smaller than inner region. As to the yearly heat budget between sea and air of each region of Seto Inland Sea, it was clarified in this study that heat flux from sea to air exists and that heat flux which keeps balance of heat budget between sea and air flows into the Seto Inland Sea from the open sea. The yearly means of sea surface temperature of Bisan Seto and western part of Harima Nada are the lowest in Seto Inland Sea, because advective heat flux from the open sea is small. Sea surface salinity of the eastern region is relatively lower than that of the western region. Salinity of each region varies corresponding to the amount of discharged water from rivers before one to three months salinity observation. Relative horizontal distribution of salinity doesn't change seasonally, because relative fluctuation of monthly discharge water volume from each river is similar to one another. As results of the classification of the seasonal variation types of oceanographic condition in Seto Inland Sea on the basis of the characteristics of seasonal variation of temperature and salinity at each sector, six types are found which are recognized in Suo Nada, Bungo strait and Iyo Nada, Aki and Hiuchi Nada, Bisan Seto, Harima Nada and Osaka Bay, Kii strait, respectively. It is clarified that the seasonal variation of oceanographic condition in Seto Inland Sea is fundamentally controlled by seasonal variation of salinity. Fishing condition in relation to temperature and salinity which are the fundamental factors of characteristics of oceanographic condition, and to discharged waters from rivers and to factors of weather, are investigated by means of a multiple regression analysis. Fish and cephalopod species selected for this study are Japanese anchovy, sand lance, common seabass, horse mackerel, cuttlefish, octopus, and gray mullet. Landing by months of good catch are set up as the dependent variables. Water temperature, salinity, transparency, discharge water volume, air temperature, solar radiation, precipitation, east and north component of wind vector in one and two months before fishing catch, are set up as the independent variables. In order to get the multiple regression equation for catch prediction, relationship between dependent and independents is calculated by a foward selection method. Results of these relationships in most species are almost significant at 5 % level statistically. Therefore, it is possible to predict the catch of those objective fish species by using the above-mentioned environment factors. In early June 1977, duration of abundant occurrence of anchovy, current of sea surface water, water temperature and salinity were continuously observed for 15 days and simultaneously, echo survey of anchovy was done twice a day in Yuya Bay. Fluctuation of standing crop of anchovy corresponded with current pattern of open sea water flowing into the Bay. It is estimated that the fish schools drift along the anticlockwise circulation in the Bay and exchange with one after another at a few days interval. Synthetically, on the basis of the data up to the present in Seto Inland Sea, the characteristics of seasonal variation of oceanographic structure, and also the relation between fishing condition of the useful fish species and factors of oceanographic condition are clarified. Furthermore, a new method of quantitative prediction of catch is find out, of which little information has been obtained. On the other hand, through the continuous observation at the field in Yuya Bay, it is supposed that a possible factor which causes immigration of anchovy fly or emigration seems to be movements of water body of the Bay on meso-scale which are the phenomena in time scale examined scarecely. | |||||
| 言語 | en | |||||
| 書誌情報 |
ja : 水産大学校研究報告 en : The Journal of the Shimonoseki University of Fisheries 巻 34, 号 1, p. 1-103, ページ数 103, 発行日 1986-01-31 |
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| 出版者 | ||||||
| 出版者 | 水産大学校 | |||||
| 言語 | ja | |||||
| 出版者 | ||||||
| 出版者 | the Shimonoseki University of Fisheries | |||||
| 言語 | en | |||||
| ISSN | ||||||
| 収録物識別子タイプ | PISSN | |||||
| 収録物識別子 | 0370-9361 | |||||
| 書誌レコードID | ||||||
| 収録物識別子タイプ | NCID | |||||
| 収録物識別子 | AN00124678 | |||||
| 情報源 | ||||||
| 識別子タイプ | Local | |||||
| 関連識別子 | fishu_k_34_1 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://agriknowledge.affrc.go.jp/RN/2010343538 | |||||
| 言語 | ja | |||||
| 関連名称 | 日本農学文献記事索引(agriknowledge) | |||||
