A TRIAL TO ESTIMATE THE INSTANTANEOUS RATE OF NATURAL MORTALITY OF ADULT SALMON (Oncorhynchus sp.) AND THE CONSIDERATION OF RATIONALITY OF OFFSHORE FISHING-II
サケ成魚 (Oncorhynchus sp.) の自然死亡係数を推定する一つの試み,ならびにこれに基づく沖取漁業の合理性の検討-II

Kisaburo TAGUCHI
1961 Nippon Suisan Gakkaishi  
As to the consideration about the rationality of offshore fishing for chum salmon, it has been tried in the previous paper (1) of this report on the basis of the estimation of the ins tantaneous rate of natural mortality. Also in red salmon, since the same kinds of data have been given, the same estimation and consideration for red salmon were tried with the same purpose and method. Adopting the symbols as bellow equally in the case of chum salmon, next formulas are given. R0¥¥¥¥Size of mature
more » ... ¥¥¥¥Size of mature salmon run in number of fish in offshore waters. R¥¥¥¥Size of mature salmon run in number of fish in coastal areas. C¥¥¥¥Catch of offshore fishing. C1¥¥¥¥ Catch of coastal fishing. M0¥¥¥¥Instantaneous rate of natural mortality. M1¥¥¥¥Instantaneous rate of mortality by net-mark. F0¥¥¥¥Instantaneous rate of fishing mortality. F1¥¥¥¥Instantaneous rate of occurrence of net-mark. t0¥¥¥¥Term of offshore fishing (Number of day). t1¥¥¥¥Term of migration from offshore to coast (Number of day).
doi:10.2331/suisan.27.972 fatcat:32xj2ob2tjbiphos3fqvesiida