Using Data-Limited Methods to Assess the Status of Bartail Flathead Platycephalus indicus Stocks in the Bohai and Yellow Seas

We applied Catch and Maximum Sustainable Yield (CMSY), Bayesian Schaefer model (BSM), and Abundance Maximum Sustainable Yield (AMSY) methods to estimate the status of Platycephalus indicus stocks in the Bohai and Yellow Seas, assessed model performance, and determined the impact of priors derived from expert knowledge on the performance of each model. Results showed that P. indicus stock in the Bohai Sea had collapsed, while that in the Yellow Sea stock was recovering. With the input of an expert prior derived from the length-based Bayesian biomass (LBB) estimation method, the CIs of each model narrowed, but the changes in biomass trajectory were not significant, and the estimates of B/B-MSY were differed compared with model results using default rules. These three models can be used to evaluate data-limited stocks to reflect stock dynamics when reliable inputs are available. However, the ranges of priors, which are preferably obtained from other stock assessment tools, should be carefully established.

Automated summary

In this study, we applied CMSY, BSM, and AMSY methods to assess the status of Platycephalus indicus stocks in the Bohai and Yellow Seas. The results showed that the stock in the Bohai Sea has collapsed, while the stock in the Yellow Sea is recovering. The input of expert priors narrowed the confidence intervals of each model, but the changes in biomass trajectory were not significant and the estimates differed from the default rules. These models can be useful for data-limited stocks, but the range of priors should be carefully established.