Xu Guoqiang, Zhang Hongliang, Zhou Yongdong
Zhejiang Marine Fisheries Research Institute, Zhoushan, 316021, China.
Scientific Observing and Experimental Station of Fishery Resources for Key Fishing Grounds, Ministry of Agriculture and Rural Affairs, Zhoushan, 316021, China.
Sci Rep. 2025 Jul 1;15(1):22429. doi: 10.1038/s41598-025-02748-8.
The marine ecological environment of Hangzhou Bay and its adjacent waters ( 30°-31° N, 121.5-123.5° E ) shaped by various factors, serves as a spawning and feeding ground for diverse species of fish, shrimp and crabs, including a traditional gillnet fishing area for the gazami crab, Portunus trituberculatus. The study investigates spatiotemporal distribution and the mechanisms underlying the formation of these fishing grounds of P. trituberculatus using single bottom trawl survey data from 31 stations in Hangzhou Bay and its adjacent waters across four seasons in 2014, gillnet survey data during the period 25-29 July 2019 to 2021 and gillnet vessel fishing logs from September 2020 to January 2021. Seasonal variations and spatiotemporal distributions of P. trituberculatus abundance and body mass were analysed. A generalised additive model was applied to assess the influence of external factors identifying key drivers of fishing ground formation. Gillnet monitoring and fishing log data were used to explore inter-annual trends in population characteristics and catch per unit effort (CPUE). The findings revealed pronounced seasonal patterns in P. trituberculatus abundance and distribution, with notable seasonal differences in spatial and temporal dynamics. The primary external factors affecting abundance were season and bottom salinity, followed by latitude and surface chlorophyll a content. Bottom salinity emerged as the critical environmental factor driving the formation of the gillnet fishing grounds. Significant inter-annual differences were observed in P. trituberculatus carapace length (P < 0.05), although no significant differences were found between sexes within the same year. Monthly variation in CPUE 0.49-1.38 kg/net and carapace length 75.6-82.1 mm were also significant (P < 0.05). This study elucidates the spatiotemporal distribution patterns and environmental drivers shaping P. trituberculatus fishing grounds in Hangzhou Bay and its adjacent waters, providing insights for sustainable management and conservation of these fishery resources.
杭州湾及其邻近海域（北纬30° - 31°，东经121.5 - 123.5°）的海洋生态环境受多种因素影响，是多种鱼类、虾类和蟹类的产卵和觅食地，其中包括三疣梭子蟹的传统刺网捕捞区域。本研究利用2014年杭州湾及其邻近海域31个站点四个季节的单底拖网调查数据、2019年7月25日至2021年期间的刺网调查数据以及2020年9月至2021年1月的刺网渔船捕捞日志，调查了三疣梭子蟹渔场的时空分布及其形成机制。分析了三疣梭子蟹丰度和体重的季节变化以及时空分布。应用广义相加模型评估外部因素的影响，确定渔场形成的关键驱动因素。利用刺网监测和捕捞日志数据探索种群特征和单位捕捞努力量（CPUE）的年际趋势。研究结果显示，三疣梭子蟹的丰度和分布呈现出明显的季节性模式，时空动态存在显著的季节差异。影响丰度的主要外部因素是季节和底层盐度，其次是纬度和表层叶绿素a含量。底层盐度是驱动刺网渔场形成的关键环境因素。三疣梭子蟹的甲长存在显著的年际差异（P < 0.05），尽管同一年份内雌雄之间没有显著差异。CPUE在0.49 - 1.38千克/网之间的月度变化以及甲长在75.6 - 82.1毫米之间的月度变化也很显著（P < 0.05）。本研究阐明了杭州湾及其邻近海域三疣梭子蟹渔场的时空分布模式和环境驱动因素，为这些渔业资源的可持续管理和保护提供了见解。
