魚礁効果の表現について

スポンサーリンク

概要

• 論文の詳細を見る

• The numerical estimation of stock capacity in the fishing ground affected by “Gyosho”, which is a kind of artificial reef being use to increase the stock of fish, is supposed to be essential studies on its structure and setting. For this subject the author tried to analyse the catch data in the fishing ground by the mathematical method originated in its fundamental observations, and a following differential equation on the stock and fishing effort was assumed. dS/dt=kN(C-S)=fS, df/dt=a-h(C-S)f, where, C-capacity of “Gyosho”. S-stock remained in “Gyosho”. N-density of population migrated in this ground. f-fishing coefficient. a-the most strong level of the increasing tendency of fishing. others-coefficients. But, in the state of equilibrium between stock and fishing effort, the coefficient ?? may be shown by the function of catch ??, as follows: ?? ( ?? )=a/hC+ ?? /C, Furthermore, it was recognized that the point f*, near by ?? showed the vibrating change in relation to catch, therefore, the equilibrium was instability. Conversely, by the application of moving average for this vibrating change, it was recognized too, that the equilibrium equation approximatelyequalled to ?? ( ?? ) was drawn from ?? ( ?? ) and from this equation the capacity of “Gyosho” was calculated. By application of this method for the data obtained from Aio Fishing Guild, Yamaguchi Pref., it was supposed the effect was appeared from two to four years after setting.

• 公益社団法人 日本水産学会の論文

著者

• 岡 正雄

  長崎大学水産学部

関連論文

• コウライエビの研究-VIII : リンパ様未知器官の構造
• 魚礁効果の表現について
• マダイ人工放流魚と天然当歳魚の外部形態の比較〔外部形態によるマダイ人工放流魚と天然当歳魚の比較と識別-1-〕
• 判別関数を用いた外部形態によるマダイ人工放流魚と天然当歳魚の識別〔外部形態によるマダイ人工放流魚と天然当歳魚の比較と識別-2-〕
• Studies on a Dietary Disease in Cultured Yellw Tails.

スポンサーリンク