The impact of different sampling designs on the estimation accuracy of fishery resources in the southern offshoreSof zhejiang province

Abstract:

In order to more accurately understand the status of fishery resources in the southern offshore waters of Zhejiang Province under the influence of multiple factors such as climate change, this study utilized the bottom trawl survey data in in 2019 to obtain the "true value" of fish stock size by the Kriging spatial interpolation method, and the estimation accuracy of three sampling methods, Simple Random Sampling (SRS), Systematic Sampling (SyS), and Stratified Sampling (StS) for the population mean under different numbers of sampling stations was evaluated through computer-simulated resampling.. The results showed that under small sample size conditions (sampling station size<35), the sampling accuracy of SyS method fluctuated greatly, especially in spring, while SRS and StS methods performed relatively stably. As the number of stations increases, the coefficient of variation (CV) and relative estimation error (REE) of the three methods significantly decrease; Under large sample size conditions, the StS method demonstrated the best performance and highest stability in terms of CV and REE.. Although the CV and REE of SyS are better than SRS, their relative bias (RB) fluctuates significantly and the stability is insufficient. Taking into account the station quality of current survey and estimation accuracy, it is recommended to prioritize the use of the StS method in the investigation of fishery resources in the southern offshore of Zhejiang, and gradually construct a seasonal differentiated investigation plan with StS as the core. This study provides theoretical reference for optimizing the resource survey plan in the study area.