采样频次对渔业资源调查物种丰富度估计的影响

合理的调查采样设计可有效降低调查成本、获取高质量的调查数据。为深入理解采样频次对渔业生物物种丰富度估计的影响,本文基于2009—2010年胶州湾近岸水域逐月张网的渔业调查数据,采用计算机模拟重抽样方法,比较了简单随机抽样和两种分层随机抽样方案下不同采样频次在物种丰富度估计方面的表现。研究表明,三种采样方案下的物种丰富度的相对估计误差(REE)和相对偏差(RB)绝对值均随采样频次的增加而降低;简单随机抽样的REE值和RB值的绝对值略高于分层随机抽样;物种丰富度探测率达到90%、80%和70%时分别需要进行10、8和6次调查。对于胶州湾等温带半封闭海湾渔业生物多样性的调查,调查频次应尽可能覆盖全年以保证调查数据的代表性。

Effect of Sampling Frequency on Species Richness Estimation in Fishery-Independent Surveys

The optimal sampling design can effectively reduce the survey cost and obtain high quality data.In order to ascertain the effect of sampling frequency on the estimation of species richness,the performances of simple random sampling and stratified random sampling designs with different sampling frequencies were compared using resampling approach based on the data collected from the setnet survey in the coastal waters of Jiaozhou Bay from 2009 to 2010 in this computer simulation study.Relative estimation error(REE)and relative bias(RB)were used to measure the precision and accuracy of estimates of species richness in different situations.The results showed that both REE and absolute value of RB of species richness estimates decreased with the increase of sampling frequency in all sampling designs.The REE and absolute RB values in simple random sampling designs were slightly higher than those in stratified random sampling designs.The detectability of species richness at 90%,80%and 70%needs to survey 10,8,and 6 times one year,respectively.For the fishery biodiversity monitoring survey in the temperate semi-closed shallow bay,the sampling frequency should be high enough to cover as many months as possible throughout the year to ensure the representativeness of survey data.