National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, PR China.
Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, United States of America.
PLoS One. 2020 Dec 29;15(12):e0244495. doi: 10.1371/journal.pone.0244495. eCollection 2020.
Species distribution monitoring and biomass assessment are crucial for fishery management and resource conservation. However, traditional methods such as motor trawling are costly and less effective than the novel environmental DNA (eDNA) approach. This study employs eDNA approach to investigate horizontal and vertical distributions of small yellow croaker (Larimichthys polyactis), an economically important species, in the East China Sea. The analysis of 171 eDNA samples collected from 44 stations using the species-specific primers and Taqman probe suggests a presence of small yellow croaker at 28 sampling layers in 44 stations. Significant differences in croaker eDNA concentrations were revealed among sampling stations and layers, consistent with previous findings through motor-trawl capture offshore and nearshore ichthyoplakton surveys, indicating small yellow croaker exhibits strong regional distribution and layer preference. In addition, we found a high eDNA concentration of small yellow croaker in the surface waters beyond the motor-trawl prohibition line, which confirms spawning grounds have been expanded from nearshore to offshore areas. Such expansion of spawning grounds could be a response by small yellow croaker to stressors such as overfishing, climate change, and nearshore environment contamination. To identify environmental variables potentially associated with small yellow croaker presence and absence, we conducted a correlation analysis between eDNA concentration and environmental variables, and the results provide a guideline for further investigation of fishery resources in the future. In conclusion, this study demonstrates the power of the eDNA approach in monitoring small yellow croaker at extensive geographic scales. The developed protocols and the findings are expected to assist in long-term monitoring and protection programs and benefit sustainable fishery in small yellow croaker.
物种分布监测和生物量评估对于渔业管理和资源保护至关重要。然而，传统方法（如机动拖网）成本高，效果不如新型环境 DNA（eDNA）方法。本研究采用 eDNA 方法调查了东海小黄鱼（Larimichthys polyactis）的水平和垂直分布，小黄鱼是一种经济上重要的物种。使用物种特异性引物和 Taqman 探针对从 44 个站位采集的 171 个 eDNA 样本进行分析，结果表明在 44 个站位的 28 个采样层中存在小黄鱼。在采样站位和层之间，小黄鱼 eDNA 浓度存在显著差异，与通过近海和近岸浮游生物拖网捕获的先前研究结果一致，表明小黄鱼表现出强烈的区域性分布和层偏好。此外，我们发现禁渔线以外的表层水中小黄鱼的 eDNA 浓度很高，这证实了产卵场已经从近岸扩展到了近海区域。这种产卵场的扩展可能是小黄鱼对过度捕捞、气候变化和近岸环境污染等压力的一种反应。为了确定与小黄鱼存在和不存在相关的环境变量，我们对 eDNA 浓度与环境变量之间进行了相关性分析，结果为今后渔业资源的进一步调查提供了指导。总之，本研究展示了 eDNA 方法在广泛地理尺度上监测小黄鱼的能力。所开发的方案和研究结果有望有助于长期监测和保护计划，并促进小黄鱼的可持续渔业。
