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題 名 | 剩餘生產量模式應用於資源評估之檢討=Reconsideration of Assessing Fish Stocks with the Surplus Production Model |
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作 者 | 王健雄; | 書刊名 | 臺灣海洋學刊 |
卷 期 | 35:4 1996.12[民85.12] |
頁 次 | 頁375-394 |
分類號 | 439.2 |
關鍵詞 | 剩餘生產量模式; 改良式剩餘生產量模式; Surplus production model; Improved surplus production model; |
語 文 | 中文(Chinese) |
中文摘要 | 以剩餘生產量模式:dB/dt= rB(1-B/K)-Y,式中; B為資源量,t為時間,r為 潛在成長率,K為環境收容力,Y=FB= 漁獲量,F=qX=漁獲死亡率,q為漁獲率,X為努力 量,進行資源評估時.若設定資源變動旦為零(SP.M法)時,可求得,最適漁獲量 Y'op=r1K1/4,最適努力垃X1op= r1/2q1,最適資源量指數U1op =q'K'/2,最適漁獲死亡係 數F1op = r1/2,最適資源量B1op = K'/2。 資源量在漁業持續的影響之下,於Bm=(K/2)(1-F/r)時的再生產量最大。因此,漁業管 理的目標若設定在Y=FBm= 再生產量(IPM法),可同時達成資源永繽的平衡,漁業永續的經 營,以及資源有效的利用等三大目標。此時可求得:最適漁獲量Y op =rK/9,最適努力量X op = r/3q,最適資源量指數U op =qK/3,最適漁獲死亡係數F op =r/3,最適資源量B op =K/3。比之於SPM法,IPM法具有如下的優點:1.應用於漁業管理時.雖然IPM法的最 適漁獲量較小,但是可以用較小的努力量獲得較高的單位努力漁獲量。2.除非是所得高達成 本的三倍,否則業者將可由此獲得較高的利潤。3.最適漁獲死亡係數較低,最適資源量較 高,對於資源的保護較為有利。4﹒清楚的資源量、再生產量、漁獲量與漁獲死亡係數之間 互動關係,有助於檢視漁業管理的結果。 |
英文摘要 | In assessing fish stocks with the Surplus Production Model (SPM), the temporal (t) change in the biomass B is dB = rB (1-B/K)-Y, where r= the intrinsic growth rate, K= the carrying capacity, Y= the catch, F= qX = the fishing mortality rate, q = the catchability and X= the fishing effort. When applying SPM method in assessing fish stocks, some points are worth noting. Results revealed that the optimal catch Y1op=r1K1/4, the optimal effort X1op = r1/2q1, the optimal catch per unit of effort U1op = q1K1/2, the optimal fishing mortality rate F1op = r1 /2 and the optimal biomass B1op = K1/2. If human exploitation exists continuously, then the maximum production occurs as the biomass Bm = (K/2)(1-F/r). The management of fisheries should assume that the catch equals the maximum production, or Y = FBm (the improved SPM, or the IPM method). In this way, it was found that the optimal catch Yop =rK/9, the optimal effort Xop = r/3q, the optimal catch per unit of effort Uop = qK/3, the optimal fishing mortality rate Fop = r/3 and the optimal biomass Bop = K/3. Compared with the SPM method, the IPM method affords several advantages: (1) a higher catch per unit of effort (CPUE) can be obtained with less effort even if there is a lower optimal catch; (2) fishermen can expect a higher net revenue unless the revenue is greater than three times their costs; (3) a lower optimal fishing mortality rate and a higher optimal biomass imply that the IPM method is more appreciable for population conservation; and (4) the clear relationships among biomass, production, catch and fishing mortality rate are useful for examining the result of fishery management. |
本系統中英文摘要資訊取自各篇刊載內容。