环境DNA技术在象山港水域鱼类多样性调查中的应用与评估

通过对象山港水域环境 DNA (eDNA)样品的采集和高通量测序分析, 并结合渔业资源调查数据, 阐述象山港主要鱼类群落的种类组成和多样性特征, 探讨了环境 DNA 技术在典型海域鱼类多样性研究中的应用前景。结果显示, 共从象山港水域环境 DNA 样品中检测到 26 个常见鱼类物种, 隶属于辐鳍鱼纲(Actinopterygii)的 7 个目中的 21 个属。其中, 丰度最高的两个目为鲱形目(Clupeiformes)、鲈形目(Perciformes), 其相对丰度合计占到总鱼类物种丰度的 92.5%。在所有鱼类中, 象山港海域渔获物中资源量较高的斑鰶(Konosirus punctatus)和黑棘鲷(Acanthopagrus schlegelii)在环境 DNA 调查中序列丰度最大, 分别占到鱼类总丰度的 45.85%和 17.69%, 其次是髭缟虾虎鱼 (Tridentiger barbatus)和花鲈(Lateolabrax japonicus), 几个门类序列丰度与渔获物种资源量组成变化趋势相似。与传统调查方法相比, 环境 DNA 测定灵敏性高、数据准确性高且成本低, 适用于相关海域的鱼类多样性研究。本研究不仅可以丰富象山港水域生态系统的结构功能信息, 还可以为系统开展该水域海洋生态系统管理与修复工作提供基础信息支持。

Application and evaluation of environmental DNA technology in fish diversity research in Xiangshan Bay

Fish are one of the key groups of organisms in marine ecosystems and are also the main object of marine fisheries. Knowledge of their diversity and distribution not only provides basic data for the sustainable development and utilization of marine ecosystems but also set up a theoretical basis for evaluating the influence of human disturbance factors (such as marine development and fishing) on these ecosystems. With the rapid development of biotechnology in recent years, environmental DNA (eDNA) technology has been gradually applied in the field of ecology owing to its advantages in sensitivity, accuracy, and cost, but there have been few local surveys of marine fish resources and their diversity using eDNA, especially in the local marine areas and fishing grounds. Xiangshan Bay is a semi-closed narrow harbor that is located on the north coast of the central Zhejiang Province, China. For years, overfishing, environmental pollution, and large-scale marine development activities have caused the ecological environment to deteriorate, and fishery resources have declined. Biological resource studies in Xiangshan Bay are still insufficient, and research on fish community structure and diversity are lacking. However, owing to the existence of many artificial and natural reefs, fish trawling surveys cannot be carried out in the area, which also limits the routine detection of fish biodiversity (especially for reef-dwelling fish) in the area. Therefore, the application of eDNA technology is of great significance to the assessment of fish biodiversity in Xiangshan Bay. In the present study, by eDNA sample collection and high-throughput sequencing analysis, combined with survey data of fishery resources in the same region, the fish species composition and diversity characteristics of the main fish communities in Xiangshan Bay were expounded. The prospect of applying eDNA technology in fish diversity studies of typical sea areas was also discussed. The results showed that 26 common fish species (belonging to seven orders of Actinopterygii and from 21 genera) were detected from the aquatic eDNA samples from Xiangshan Bay. Two orders with the highest abundance were Clupeiformes and Perciformes, whose relative abundance accounted for 92.5% of the total fish species abundance. Among all the fish species identified from eDNA analysis, Konosirus punctatus and Acanthopagrus schlegelii had the highest abundance, which accounted for 45.85% and 17.69% of the total fish abundance, respectively. Both species also contributed the most to fisheries resources in Xiangshan Bay. The next most abundant species were Tridentiger barbatus and Lateolabrax japonicus. The sequence abundances of such taxa were similar to the trends in the fisheries catch data. Compared with traditional survey methods, the eDNA analysis had high sensitivity, high accuracy, and low cost and was suitable for studying the fish diversity of relevant sea areas. The present research not only enriched the structural and functional information of the Xiangshan Bay aquatic ecosystem but also provided basic information to support the management and restoration of marine ecosystems in this marine area.