||機船底曳網の漁具と漁獲性能に関する研究II : 曳船の曳網力と以東底曳網の漁獲量との関係について
Studies on the Relationship between the Gear-types and the Fishing Efficiencies in the Trawl Nets II : Relationship between the Towing Force of the Trawler and the Catch of the Eastern Net
キセン ソコビキアミ ノ ギョグ ト ギョカク セイノウ ニ カンスル ケンキュウ II : エイセン ノ エイモウリョク ト イトウ ソコビキアミ ノ ギョカクリョウ トノ カンケイ ニツイテ
鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University
67 , 鹿児島大学
In the fishing operated with the use of the towing nets of the same construction, the yielded catch-differentials may, reasonably, be attributed to the difference in the towing-forse of the trawlers. Basing on the materials obtained by the subsidiary trawlers belonging to the Fish-meal fleets operating on the Bering Sea in 1963 and in 1965, the possible relationship between the catches of the eastern net and the towing-force of the trawler which is to be denoted by the resultant of the Gross tonnage and the Horse Power of the main engine was put under investigation, with the following results obtained : 1) The increase of the Horse Power of the main engine of the trawler seemed to have been coincided with the responsive increase of the catch per one unit of the towing net, which was to be observed most remarkably at the good-catching period. 2) Each increase in the total tonnage seemed to have been accompanied by the increase in the catch per one unit of the towing net, though this was not so remarkable as in the above mentioned case. 3) The towing speed might be regarded as one of the chief factors in the formation of this relationship between the catch and the Horse Power of the main engine, but the versatility of the towing speed, easily influenced by the net-size, sea-condition and the catches make necessary the execution of the spot investigations.