体長組成推定に際して現われる統計量の生物學的意味について(豫報)
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概要
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The variance of the simple estimates of the number belonging to a certain body length class is rather large and is composed of three components, i.e., between-day variance, between boat one and within boat one. As an example, the drift net fisheries of Japanese Sardine was taken. The second and the third one are at their maximum near the modes of body length composition, while at their tails they are comparatively low. When we use the ratio estimation in order to separate the variance which dues to the variation of the size of shoals from that due to the heterogenuity within the shoals, we find that the correlation coefficients between the total catch of a sample boat and that in a certain length class are, in generally, largest at the modes of the body length compositions, while at the larger tails, they are low. This fact is considered to be caused because the main year class and the younger ones build up shoals with the individuals of the same size, while the older ones migrate independently.
- 公益社団法人 日本水産学会の論文