汕头大学学报（自然科学版）

鱼类堵塞滨海电厂循环水通道滤网或大规模进入循环水通道，将对滨海电厂的运行造成严重的影响，导致重大经济损失.为了解滨海电厂循环水通道中鱼类群落的生物多样性及其时空演变规律，发现循环水通道中的潜在致灾物种，我们在夏季（6、7月）、秋季（9、10月）、冬季（1月）分别利用环境DNA(Environmental DNA,eDNA)宏条形码技术对汕头海门电厂循环水通道5个位点的鱼类生物多样性进行分析.我们从69份eDNA样品中一共检测出32目，71科，138属，149种鱼类，其中鲱形目鱼类丰度最高，占鱼类read总数的24.85%.此外，相对丰度较高的物种为花莲沙丁鱼、褐菖鲉、斯氏凡鲻、白点蓝子鱼、褐篮子鱼、长头小沙丁鱼、裴济小沙丁鱼、平鲷、鲻鱼、岛侧带小公鱼等.各月份的鱼类Alpha多样性差异较大，9月份的Shannon指数、Simpson指数、物种数量和Chao1指数均是各个月份中最低的，前两者从夏季到冬季大体呈现V型变化，先下降再提升；后两者则在1月份再次下降.每个月份的优势物种组成呈现明显变化，在夏季，多种鲱科鱼类成为优势物种，这是一种常见的滨海电厂致灾鱼类物种，应当引起关注.本研究证明了eDNA技术用于监测滨海电厂鱼类多样性及其时空演变规律的可行性，揭示了滨海电厂冷却循环水系统中鲱科鱼类带来的风险，为控制和管理海洋鱼类对滨海电厂安全运行的影响提供基础数据支持和科学依据.

When fish get into the circulating water channel or clog the filter, it will seriously affect the functioning of coastal power plants and result in large financial losses. In order to understand the biodiversity of fish communities and their spatio-temporal variation in the circulating water system of coastal power plant and identify the species that cause disasters, the environmental DNA(eDNA)metabarcoding technique is used to investigate the fish biodiversity in summer(June and July), autumn(September and October), and winter(January)at five loci in the circulating water of the Haimen Power Plant in Shantou, China. The study identified a total of 32 orders, 71 families, 138 genera, and149 species of fish from 69 eDNA samples. Among them, the Clupeidae fish exhibited the highest abundance, making up 24.85% of the total fish seen. In addition, the species with high relative abundance were Sardinella hualiensis、 Sebastiscus marmoratus、 Valamugil speigleri、 Siganus sutor、 Siganus fuscescens、 Sardinella longiceps、 Sardinella fijiensis、 Rhabdosargus sarba、Mugil cephalus and Stolephorus insularis. The Alpha diversity exhibited significant variation over the months, with September displaying the lowest values for the Shannon index, Simpson index,Observed species index, and Chao1 index compared to all other months. The initial two indexes had a V-shaped fluctuation from summer to winter, initially declining and subsequently rising, but the last two experienced a subsequent decline in January. The composition of the dominating species exhibits significant variability among months. It is important to focus on the prevalence of herring fish throughout the summer, as they are typically species that cause disasters in coastal power plants. The study demonstrated the viability of using eDNA technology for monitoring fish diversity in the coastal power plant and analysing their temporal and spatial variations. It also identified the risks associated with Clupeidae fishes in the cooling circulating water system of the power plant. Furthermore, the study provided essential data and a scientific foundation for controlling and managing the impact of marine fishes on the safe operation of the coastal power plant.