Wang Sifan, Wu Fengxia, Gong Xiuyu, Liu Huaxue, Rao Yiyong, Zhang Shufei, Hou Gang, Huang Honghui
Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.
College of Fisheries, Guangdong Ocean University, Zhanjiang, China.
Mar Environ Res. 2025 Oct;211:107339. doi: 10.1016/j.marenvres.2025.107339. Epub 2025 Jul 14.
Hydrographic characteristics and water mass changes are essential for understanding fish egg distribution and for the protection and management of marine ecosystems. In this study, four cruises were conducted in May (spring), July (summer), September (fall), and December (winter) of 2022 to investigate early fish resources and environmental characteristics in Daya Bay waters. The K-means clustering algorithm was employed to classify water masses in Daya Bay, and the distribution patterns of temperature and salinity, along with their seasonal variations, were systematically analyzed. Additionally, based on the classification of water masses, we compared fish egg communities between seasons and water mass regions to examine the structure of fish egg communities under different hydrographic conditions. The main findings of this study were as follows: in the present study, 51 fish egg species were identified, belonging to six orders, 22 families and 35 genera. The number of fish egg species ranged from high to low was spring, summer, autumn and winter, while the average abundance ranged from high to low was spring, summer, winter and autumn. The K-means clustering method was utilized to classify Daya Bay into coastal water mass (CWM), nuclear power plant warming water mass (NWWM), high salinity water mass (HSW) outside Daya Bay, mixed water mass (MWM) and Pearl River dilution water mass (PRDWM). By integrating salinity and water temperature data, we identified associations between fish eggs and specific water masses. The mean abundance of fish eggs was highest in thermal discharge from nuclear power plants during spring and autumn; in seasonally mixed water during summer; and in littoral water of the Bay during winter. These results indicate that the thermal discharge from nuclear power plants has had specific effects on the water masses in the adjacent sea areas, forming a distinct oceanic water temperature fronts. This may played a positive impact on the spawning and nursing of some fish species, facilitating the recruitment of fish resources in Daya Bay.
水文特征和水体变化对于理解鱼卵分布以及海洋生态系统的保护和管理至关重要。在本研究中，于2022年5月（春季）、7月（夏季）、9月（秋季）和12月（冬季）进行了四次巡航，以调查大亚湾水域的早期鱼类资源和环境特征。采用K均值聚类算法对大亚湾的水体进行分类，并系统分析了温度和盐度的分布模式及其季节变化。此外，基于水体分类，我们比较了不同季节和水体区域之间的鱼卵群落，以研究不同水文条件下鱼卵群落的结构。本研究的主要发现如下：在本研究中，共鉴定出51种鱼卵，隶属于6目、22科、35属。鱼卵种类数量从高到低依次为春季、夏季、秋季和冬季，而平均丰度从高到低依次为春季、夏季、冬季和秋季。利用K均值聚类方法将大亚湾分为沿岸水体（CWM）、核电站温排水体（NWWM）、大亚湾外高盐水体（HSW）、混合水体（MWM）和珠江冲淡水体（PRDWM）。通过整合盐度和水温数据，我们确定了鱼卵与特定水体之间的关联。鱼卵的平均丰度在春季和秋季核电站温排水中最高；夏季在季节性混合水体中最高；冬季在大亚湾沿岸水体中最高。这些结果表明，核电站温排水对邻近海域的水体产生了特定影响，形成了明显的海洋水温锋面。这可能对一些鱼类的产卵和育幼起到了积极作用，有利于大亚湾鱼类资源的补充。
