スケソウ漁業中の以東底曳船の作業時間-IV. : 深度の影響より漁獲の深度差の影響を除去

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The influence of the depth on working times of the Danish seiners after removal of the influence of the bathymetric difference of catch, was examined by estimating the regressive relation of working time on depth observable among the hauls with the same grades of catch and by estimating the bathymetric difference of the regressive relation of the working time on catch. And the results obtained are summarized as follows: 1. The influence of depth on working time was faint, because a depth of 150m was still shallow fishable without adjustment of the warp length. 2. In the hauls with ordinary catch (1 to 5 tons), the time to complete a haul increased with depth at a rate of 3.5 to 5 min. per 100m, because of the same trend of the time expended on other steps of works than hauling-brailing step, probably sinkingpulling step. 3. In the hauls with good catch (6 to 8 tons), the hauling-brailing time decreased with depth, but this was offset by the increase in the sinking-pulling time; as the consequence, the time to complete a haul did not show significant difference according to depth. 4. The regressive coefficients of the hauling-brailing times on catch took the similar values throughout the depth zones. This suggested such a possibility that the increase in the time with catch was due to the same trend in the step having no direct relation to depth. The same could be said to the time to complete a haul.
公益社団法人日本水産学会の論文