Abstract Fisheries management and resource conservation rely upon accurate information on the distribution and abundance of major species. The large yellow croaker (Larimichthys crocea) was once one of the most economically important marine fish in East Asia; however, its wild fishery resource has collapsed since the 1980s. Until recently, the natural resources of L. crocea started to increase due to the practice of stock enhancement and summer fishing moratorium. In this study, we developed the species-specific primers and probe and investigated the distribution and abundance of L. crocea using the environmental DNA (eDNA) approach. We collected 171 samples from 44 stations (190,467 km2 sea areas) in the East China Sea and detected 96 positive eDNA samples of L. crocea (56 %) at 29 stations (66 %). We found a significant difference in eDNA concentrations among different stations, indicating a regional distribution in L. crocea. We observed vertical variations in the eDNA concentrations of L. crocea among different water layers and detected the eDNA signals in water depths around 40 m and the bottom at multiple stations. We discovered eDNA hotspots with high concentrations in the Yushan fishing ground, which suggesting an offshore spawning ground might have been established possibly in response to nearshore environmental pollution and overfishing. We evaluated the effect of environmental variables on the distribution of L. crocea, found total depth and temperature were significantly correlated with the eDNA presence and concentration, and built a general linear model for the presence or absence prediction of L. crocea with environmental parameters. This study demonstrates the robustness of the eDNA approach in investigating and monitoring natural resources of a crucial marine fish and thus contributes to the long-term assessment of stocking and other strategies in fisheries enhancement.

中文翻译：

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利用环境DNA评估渔业资源：东海大黄鱼（Larimichthys crocea）

摘要 渔业管理和资源保护依赖于主要物种分布和丰度的准确信息。大黄鱼（Larimichthys crocea）曾经是东亚经济上最重要的海洋鱼类之一；然而，自 1980 年代以来，其野生渔业资源已经崩溃。直到最近，由于种群增加和夏季暂停捕捞的实践，大黄鱼的自然资源开始增加。在本研究中，我们开发了物种特异性引物和探针，并使用环境 DNA (eDNA) 方法研究了大黄鱼的分布和丰度。我们从东海的 44 个站点（190,467 平方公里海域）收集了 171 个样本，并在 29 个站点（66 %）检测到了 96 个大黄鱼 eDNA 阳性样本（56 %）。我们发现不同站点之间 eDNA 浓度存在显着差异，表明大黄鱼的区域分布。我们观察了不同水层中大黄鱼eDNA浓度的垂直变化，并在多个站点的40 m左右水深和底部检测到了eDNA信号。我们在玉山渔场发现了高浓度的eDNA热点，这表明可能是由于近岸环境污染和过度捕捞而建立了离岸产卵场。我们评估了环境变量对大黄鱼分布的影响，发现总深度和温度与 eDNA 的存在和浓度显着相关，并建立了大黄鱼存在与否预测的通用线性模型。crocea 与环境参数。这项研究证明了 eDNA 方法在调查和监测一种重要海洋鱼类的自然资源方面的稳健性，从而有助于长期评估放养和其他渔业增强战略。