黄海中国对虾环境DNA(eDNA)的垂直分布规律及其影响因素初探

A preliminary study on the vertical distribution of Fenneropenaeus chinensis environmental DNA in the Yellow Sea and its influencing factors

中文关键词: 环境DNA  中国对虾  分布规律  表层沉积物  生物量评估

英文关键词: Environmental DNA  Chinese shrimp  Distribution  Surficial sediment  Biomass assessment

中文摘要:

      准确掌握物种分布和种群动态是渔业资源评估的基础。然而，对某些种群规模小或生活史复杂的物种进行监测的难度很大。近年来，环境DNA技术快速兴起，已被广泛应用于各类物种监测、生物多样性评估和生物量评价等领域。为了解冬季中国对虾(Fenneropenaeus chinensis)越冬洄游过程中的分布情况，2019年12月在黄海中南部采集表、中、底3个水层水样，检测其中中国对虾的eDNA，并对表层沉积物进行室内实验。结果显示，中国对虾eDNA在自然水体中呈现特殊的垂直分布规律：底层浓度高，表层浓度低，这一规律与中国对虾生活习性相关；表层沉积物会在外力作用下再悬浮，并向周围释放eDNA，对水体造成较大程度影响，本研究将采集到的表层沉积物分为3个实验组，3个实验组最大释放量分别为1624.06、3453.34和1143.24 copies/L，沉积物对水体的影响持续1周左右。

英文摘要:

      Accurate knowledge of species distributions and population dynamics is the basis for fishery resource assessments. However, it is difficult to monitor certain species with small populations or complex life histories. Recently, as a new monitoring technology, environmental DNA (eDNA) has been widely used in species monitoring, biodiversity assessments, and biomass assessments. In this study, eDNA technology was employed to understand the distribution of Chinese shrimp during its winter migration. In December 2019, we collected water samples from three water layers in the south-central Yellow Sea to test the eDNA of Chinese shrimp Fenneropenaeus chinensis. In addition, laboratory experiments were carried out on the surficial sediments of the seabed. First, it was found that the eDNA of Chinese shrimp exhibited a specific vertical distribution in the natural water, which was characterized by a high concentration in the bottom layer and low concentration in the surface layer. This distribution is related to the life habits of Chinese shrimp. Second, the surficial sediments would re-suspend and release eDNA to the surrounding areas under the action of external forces, causing a large impact on the water. In this study, the surficial sediments were divided into three experimental groups. The maximum amounts of eDNA released by the three experimental groups were 1624.06, 3453.34, and 1143.24 copies/L, the effects of which lasted for approximately a week. It is hoped that this study will assist with the eDNA sampling design in the future.