釣獲率よりするビンナガ魚群態の算定理論

概要

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1. The histogram of the frequency of fishing rates in long-line albacore fishing on the Pacific Ocean (N: 24°-45°, E : 130*-180°) shows some what significant modes. 2. The author interpreted the meaning of this modes by surmising that it may be caused by a long-line encountering with several albacore shoals. And he paid ome efforts to resolve the dimensions of shoals and its distributions under the consideration of the probability in the "Buffon's needle problem ". 3. By assuming that the shape of shoal is ellips (axes 2a, 2b) and the shoals are shifting on the parallel lines (intervals 2h) at the distances 2s, the probability of n-encounterings is given as Eq. (9). 4. In an example of the result of calculations (Jan. 1949, A-region), the values of 2a, 2b, 2s and 2h are obtained as 1.6 km, 1.0 km, 9.8 km and 4.5 km respectively. It is impossible or very difficult to resolve the under-water phenomena with such a large scope as these dimensions by optical or sounding apparatus. After all it is to be the best method to use the idea discrived in this paper. 5. About the theoretical methods to resolve the problems —the number of fish in one shoal (for example, 13000), the speed of shifting in the migration (for example, about 6 km/hr), how to set a long-line to secure good catches— another paper shall be published.
鹿児島大学,カゴシマダイガク,Kagoshima Universityの論文
1956-12-30