Page 26 - 《水产学报》2026年第04期

4 期 水 产 学 报 50 卷

Population dynamics and its driving factors of small yellow croaker
(Larimichthys polyactis) in the Yellow and Bohai Seas

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1,2*
1,2
1,2
HAN Qingpeng , SHAN Xiujuan , WU Qiang , JIN Xianshi ,
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TENG Guangliang , WANG Leyan 1
(1. State Key Laboratory of Mariculture Biobreeding and Sustainable Goods,
Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs,
Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China;
2. Shandong Changdao Fishery Resources National Field Observation and Research Station, Yantai 265800, China)

Abstract: Accurate assessment of fishery population dynamics and their driving factors is fundamental to the scientific man-
agement of fishery resources. The Yellow and Bohai Seas serve as crucial habitats for numerous fishery organisms, underpin-
ning the sustainable productivity of the ‘marine granary’ in northern China. The small yellow croaker (Larimichthys polyactis)
is an economically important fish species in the Yellow and Bohai Seas, and has long been a primary target for fishing. This
study aims to accurately assess the spatio-temporal dynamics of the L. polyactis population in the Yellow and Bohai Seas,
thereby providing a scientific basis for the management of the fishery resources. Based on survey data of L. polyactis in the
Yellow and Bohai Seas and publicly available information from 2001 to 2025, this study employed spatiotemporal modelling
and spatial clustering analyses to characterize the spatiotemporal distribution patterns and long-term changes in stock abund-
ance of L. polyactis. In addition, population dynamics were systematically evaluated using a data-rich stock assessment model,
and the driving mechanisms underlying stock fluctuations were further elucidated through structural equation modelling. The
results showed that the L. polyactis mainly overwinters in waters deeper than 50 m, with a small number distributed in the 30-
50 m water range and very few in waters shallower than 30 m. In addition to the central and southeastern Yellow Sea, the
waters deeper than 50 m in the northern Yellow Sea also serve as an important overwintering ground. The interannual distribu-
tion of L. polyactis population density exhibits significant spatial heterogeneity. In the winter of 2001, L. polyactis displayed
extensive and continuous high-density distribution areas, followed by a decline in resource abundance and contraction of distri-
bution hotspots. By 2025, the center of gravity of L. polyactis population had shifted westward, and the distribution hotspots in
the central and southern Yellow Sea had achieved a certain degree of recovery. Interannual variability in population density fur-
ther revealed an uneven and spatially unbalanced recovery across regions. Results from the stock assessment model indicated
that L. polyactis recruitment exhibited high interannual variability. Fishing pressure on this species remained low during 2001-
2005, with its stock status in a healthy condition. After 2005, high fishing pressure led to a decline in the spawning stock bio-
mass and impaired recruitment potential. However, with the reduction in fishing pressure in recent years, the population has
shown signs of recovery. From 2023 to 2025, the fishing mortality coefficient (F) and spawning potential ratio (SPR) of L.
polyactis performed better than their respective target reference points. Structural equation modelling clearly revealed the dom-
inant drivers of stock dynamics. Fishing pressure is the primary cause of the decline in L. polyactis resources in the Yellow and
Bohai Seas, with its impact far exceeding other factors (path coefficient of F: –1.26). Nevertheless, existing management meas-
ures (path coefficient: 0.30) and climatic conditions (path coefficient: 0.27) have supported resource conservation and recovery.
The stock recovery of L. polyactis is constrained by the characteristics of unstable recruitment and spatial imbalance. The
impacts of fishing pressure and climatic factors on the stock dynamics of L. polyactis are often exerted through their spatial dis-
tribution pattern. As a non-spatial approach, the stock assessment model used in this study is only capable of characterizing the
temporal variations of stock status indicators of L. polyactis in the Yellow and Bohai Seas, and cannot reflect the spatial differ-
ences in stock status. Integrating spatiotemporal distribution patterns with stock status indicators suggests that relying solely on

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