刺网渔具选择性研究进展

Research progress on size selectivity of gillnet

刺网选择性研究是渔具选择性研究领域中的重要部分,其对于渔业管理、资源调查和评估等都是至关重要的。本文以刺网渔具的4种渔获方式为研究基点,通过对刺网渔具选择性特点的描述,介绍各种刺网渔具选择性曲线的表示方法。根据国外多年来对刺网渔具选择性研究方法的发展进程,对当前几种常用的选择性曲线间接估算方法(SELECT模型、同时估算选择性曲线和种群资源的方法以及同时估算A类和B类曲线的方法)的原理和运用现状进行详细介绍。对间接估算法中常用的假设条件(几何相似原理、相同渔获能力等)、估算方法的缺陷和相互之间的关系以及在进行刺网渔具选择性研究时所要关注的问题等进行了讨论。

Size selectivity of gillnet, which is crucial to fisheries management, stock survey and assessment, is a main subject in research on selectivity of fishing gear. In this paper, the selective properties of gillnet are described based on information of fishing method of gillnet. In addition, different equations denoting the selectivity curves are summarized, including normal, log normal, skew normal, gamma and bimodal distribution. Many methods used to estimate size selectivity of gillnet were developed in the past several years. Principle and application of three novel indirect estimation methods are introduced in detail, including SELECT model, method of simutaneous estimation of selectivity and population and method of simutaneously estimat- ing types A and B curves as intermediaries. We doubt the assumptions in indirect estimation method, such as the geometrical similarity principle and the same fishing power of gillnets with different mesh sizes, discuss the shortages and merits of the estimation methods, as well as the relationship between each other and provide some suggestions for the further study on size selectivity of gillnet.