Page 103 - 《水产学报》2026年第04期

4 期 邹欣泰，等：基于体长数据的舟山渔场小黄鱼资源评估 50 卷

Length-based stock assessment of small yellow croaker (Larimichthys
polyactis) in the Zhoushan Fishing Ground

ZOU Xintai , MA Luyao , WANG Jing , XU Yongjiu , ZHANG Chang ,
LI Yuru , LIU Baogui , JU Peilong *
(Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China)

Abstract: Assessing the current stock status of the Larimichthys polyactis, a fish species of high ecological and economic
value, in the Zhoushan Fishing Ground is crucial for ensuring the sustainable utilization of its resources. In response to the
decline in L. polyactis resources and the long-term lack of systematic statistical data in the Zhoushan Fishing Ground, this study
employs stock assessment methods that require only short-term length-frequency data to clarify the current stock status and
exploitation level of this population, thereby providing a scientific basis for its management and conservation. Based on length
data from 772 individuals collected during four surveys from 2019 to 2024, growth parameters (the asymptotic length, L inf , and
the growth coefficient, K) were estimated using ELEFAN methods, while the natural mortality coefficient (M) was estimated
using six empirical formulas. Different parameter combination scenarios were set up, applying both the Length-Based Spawn-
ing Potential Ratio (LB-SPR) and the Length-Based Bayesian Biomass (LBB) assessment methods. Sensitivity analyses were
performed on input parameters, and results from both methods were integrated to evaluate stock status. The LB-SPR assess-
ment indicated that the average relative fishing mortality (F/M) was 6.70, while the average spawning potential ratio (SPR) was
only 0.05. The LBB assessment revealed that the average F/M was 9.97, the average relative biomass (B/B MSY ) was 0.09, and
the ratio of mean length at first capture to optimal length at first capture (L c /L c_opt ) was 0.70. Sensitivity analyses demonstrated
that while quantitative results varied with input parameters, the conclusion regarding the stock status remained robust. All indic-
ators consistently showed that the L. polyactis stock in the Zhoushan Fishing Ground is subject to extremely high fishing pres-
sure, with critically low spawning potential and biomass, alongside significant population miniaturization. L. polyactis resource
in the Zhoushan Fishing Ground has suffered severe overexploitation. Furthermore, the stock assessment methods and proced-
ure used in this study demonstrate strong applicability and robustness under data-limited conditions, providing a methodolo-
gical reference for stock assessment research in similarly data-limited fisheries.
Key words: Larimichthys polyactis; stock assessment; LB-SPR; LBB; Zhoushan Fishing Ground
Corresponding author: JU Peilong. E-mail: jupeilong@zjou.edu.cn

Funding projects: National Natural Science Foundation of China (42206203)

中国水产学会主办 sponsored by China Society of Fisheries https://www.china-fishery.cn
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