Evaluation of fishing power for the purpose of standardizing fishing efforts between fisheries

为了减少过剩的捕捞能力，对捕捞方法和渔业的捕捞能力进行评估是必不可少的。然而，在评估渔具威力时没有区分渔具选择性和捕捞效率。本文从捕捞力的角度整理了相关术语，提出了单位努力渔获量（CPUE）的标准化方法，以及渔具选择性和相对捕捞强度的估算方法，包括可捕性、取样努力、捕捞努力等。首先，明确界定了捕捞效率、可捕性和渔获力。渔业科技工作者用来评价渔力的Tauchi渔力指数可以消除资源结构时空变化对CPUE的影响，有助于CPUE的标准化，类似于GLM的标准化。其次，利用打捞努力量数据进行SELECT模型分析，可以同时估计渔具选择性和可捕性参数。SELECT模型中的split参数表示为相对捕捞强度。我们成功地修改了SELECT模型来分析抽样努力变化的成对齿轮试验数据。第三，对SELECT模型进行放大，用于3个以上渔具的对比捕捞实验数据分析。最后，以刺网为代表的捕捞方式，研究了网目尺寸和线粗对渔具选择性和捕捞效率的影响。并以长鳝渔业为例，考察了多渔场（延绳钓、拖网、陷阱网和管锅）的捕捞方法和捕捞效果，讨论了渔业管理问题。

For the purpose of reduction in excess fishing capacity, it is indispensable to evaluate fishing power of fishing methods and fisheries. However, fishing power has been evaluated without distinguishing fishing gear selectivity from catching efficiency. This study arranged terminology in terms of fishing power, and presented methods for standardizing catch per unit effort (CPUE) and for estimating fishing gear selectivity and relative fishing intensity including catchability, sampling effort, fishing effort and so on.First, fishing efficiency, catchability and fishing effort were defined clearly. The Tauchi fishing power index that fishing scientists and technologists used to employ for evaluating fishing power can remove effects of temporal and spatial change in resources structure on CPUE, and is hence useful to standardize CPUE, which is similar to standardization by GLM.Second, the SELECT model analysis with fishing effort data can estimate parameters of fishing gear selectivity and catchability at the same time. The split parameter in' the SELECT model was expressed as relative fishing intensity. We successfully modified the SELECT model to analyze the data from paired gear tests with change in sampling effort.Third, the SELECT model was also enlarged for analyzing data in comparative fishing experiments with over-3 fishing gears.Finally, for gillnet as a representative fishing method, effect of mesh size and twine thickness on fishing gear selectivity and catching efficiency was studied. And fishing methods and performance were examined in conger-eel fisheries as an example of multi-fisheries (e.g. longline, trawl, trap-net and tube-pot) and the fisheries management was discussed.