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

Abstract:

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.