温台渔场3种经济鱼类体长频次分布与采样量间关系的比较

鱼类种群的体长分布能够反映该种群的资源变动状况,但能够有效描述体长结构信息的采样量难以确定。通过使用重采样方法计算了基于实际采样量下体长频次分布和基于模拟采样量下体长频次分布之间的均方差异值,并以温台渔场几种经济鱼类为例,比较了不同鱼种间体长频次精度和采样量间的关系,研究表明：(1)鱼种间的生物学差异、季节变化等因素对体长频次精度与采样量间关系有一定影响；(2)迭代计算中体长组数量的改变会影响体长频次精度估计的准确性；(3)为避免采样努力量的浪费,体长频次精度的大小可作为采样量优化的理论依据。由于目前国内缺乏估计体长频次精度一类的研究,本文的研究结果可对相关资源调查的设计提供一定的科学理论基础。

Comparison of the relation between the length frequency distribution and sample size for several commercial fish species in the Wentai fishing ground

Length distribution data provide insight into the dynamics of fish populations. However, it is hard to determine the sample size required to describe size structure. In order to compare the relation between the precision of frequency distributions and sample size for several commercial fish species in the Wentai fishing ground, a resampling approach was used to calculate the mean square difference of length distributions based on actual sampling size and various simulated sampling sizes. The results showed that: (1) Factors such as biological difference and seasonal variation would affect the relation of the precision of frequency distributions and sample size. (2) The accuracy for estimating the precision of length frequency distributions would be impacted by the numbers of length intervals in iteration calculation. (3) The precision of length frequency distributions could be considered as a theoretical basis to optimize sample size. For the reason of lacking domestic researches on sampling design and optimization, the results of this study could provide certain technical reference.