底拖网作业捕捞努力量标准化方法研究

An Approach to the Standardization of Fishing Effort of Bottom Trawl

本文从拖网网次渔获量的数学表达式入手,在假设捕捞效率与拖网作业宏观技术水平呈幂函数关系的情况下,推导出底拖网作业捕捞努力量和捕捞努力量指数的教学表达式。公式表明一个海域(或渔场)所投入(或所承受)的底拖网作业捕捞努力量不仅与单位渔船数量(决定渔具数量)和单位渔船主机功率有关,而且还与渔船类型(性能)、拖网网型、作业技术水平和作业时间有关。同时,作者还探讨了各有关参数的计算方法,可为底拖网作业的捕捞努力量标准化计算提供一条新的途径,而且在进行不同底拖网网型捕捞努力量标准化的同时,也完成了其年间的标准化。因此,该公式能较全面、较真实地反映底拖网作业的捕捞努力量面貌,有助于较合面地描述和理解捕捞努力量的基本概念。

Based on the relating formula, the expression of Fishing of Fishing Effort & Fishing Effort Index of the Bottom Trawl are induced on this paper. The methods used to standardize the Fishing Effort of the Bottom Trawl and to calculate every related factors are also developed here so that the standardization can be done. They are as following: 1) the total bottom trawl in an area or a fishing ground should be divided into different kinds according to the type & engine power level of boat and the type of trawl. Every variant in one kind of trawl operation can be substituted by its average or the data from sampling; 2) the factors of total yielding time and performance and efficiency of per unit trawl should be standardized simultaneously; 3) the average total yielding time of per unit trawl can be obtained from withstanding ability to wind and sea wave of every kind of boat and the statistics of climate in the area and the data from sample boat, the general performance of every kind trawl operation is given here according to the relating study and efficiency of every kind trawl operation can be substituted by the Level of Technology and Economics which can be calculated from the data of corresponding sampling boat.