Page 149 - 《水产学报》2026年第04期

4 期 毛梦琦，等：基于环境 DNA 的浙江中北部海域三疣梭子蟹时空分布 50 卷

Spatiotemporal distribution of Portunus trituberculatus in north-central
Zhejiang coastal waters based on environmental DNA (eDNA)

2
2
2
1
2
MAO Mengqi , ZHOU Yongdong , ZHANG Hongliang , XU Kaida , JIANG Rijin ,
1
2
1
WANG Haoxue , YUAN Xia , ZHAO Yunhao , WANG Xiaoyan 1*
(1. National Engineering Research Center of Marine Facilities Aquaculture,
Zhejiang Ocean University, Zhoushan 316022, China;
2. Zhoushan Field Comprehensive Scientific Observation and Research Station, Zhejiang Marine Fisheries Research Institute,
Ministry of Agriculture and Rural Affairs, Zhoushan 316022, China)
Abstract: Portunus trituberculatus is one of the most important marine economic crab species in China, supporting coastal
fisheries and regional economies. However, wild populations have experienced persistent declines in recent decades due to
overfishing, habitat degradation, and environmental change, highlighting the urgent need for efficient and reliable approaches to
assess its spatial and seasonal distribution. Conventional fishery-dependent surveys, such as bottom trawl investigations, are
often constrained by sampling selectivity, labor intensity, and spatial coverage, which may limit their ability to resolve fine-
scale population dynamics; in this context, environmental DNA (eDNA) has emerged as a promising, non-invasive tool,
although its applicability to benthic crustaceans in open marine environments remains insufficiently evaluated. Here, an eDNA-
based quantitative detection framework for P. trituberculatus was established and applied to the north-central coastal waters of
Zhejiang Province during the summer and autumn of 2024. Species-specific primers and a TaqMan probe targeting P. trituber-
culatus were designed and validated, and a quantitative real-time PCR (qPCR) assay was developed for sensitive and specific
detection in environmental samples. A total of 157 seawater samples were collected from 29 stations across two seasons, cover-
ing surface, middle, and bottom water layers, and bottom trawl surveys were conducted concurrently to provide fishery-inde-
pendent reference data. The developed primers and probe exhibited high specificity, with no cross-amplification detected in
closely related crustacean species. Horizontally, P. trituberculatus eDNA displayed pronounced spatial heterogeneity in both
seasons, with consistently elevated concentrations in the Yushan Fishing Ground, indicating this area as a key habitat and
aggregation zone. Vertically, distribution patterns differed between seasons: in summer, eDNA concentrations did not differ
significantly among layers, suggesting strong vertical mixing and rapid dispersion, whereas in autumn, eDNA concentrations
were significantly enriched in the middle layer and clear stratification was observed, reflecting seasonal changes in water-
column stability and species behavior. Furthermore, both the mean eDNA concentration and detection rate in autumn were sig-
nificantly higher than those in summer, consistent with seasonal migration and increased population aggregation. Compared
with bottom trawl surveys, eDNA analysis provided a more comprehensive indication of species presence and distribution, par-
ticularly where trawl efficiency may be limited; the combined application of eDNA monitoring and trawl surveys enabled a
refined assessment of the spatial and seasonal distribution patterns of P. trituberculatus. Overall, this study demonstrates the
effectiveness and sensitivity of eDNA techniques for monitoring benthic crab resources in open marine systems and provides a
robust scientific basis for resource assessment, ecological conservation, and the sustainable management of P. trituberculatus
fisheries.

Key words: Portunus trituberculatus; environmental DNA (eDNA); traditional survey methods; distribution characteristics;
biomass; north-central Zhejiang

Corresponding author: WANG Xiaoyan. E-mail: wangxiaoyan@zjou.edu.cn
Funding projects: National Key Research and Development Program of China (2023YFD2401901, 2020YFD0900804);
Project of the Zhoushan Science and Technology Bureau (2025C31034); Survey and Habitat Environment Monitoring Project
for the Hairtail Germplasm Resource Conservation Zone of the Zhoushan Municipal Bureau of Marine Economic Develop-
ment (SZGXZS2025091); National Natural Science Foundation of China (41806180)

中国水产学会主办 sponsored by China Society of Fisheries https://www.china-fishery.cn
11