Numerical Simulation on the Diffusion of Alien Phytoplankton in Bohai Bay

Beibei Zhang,Wenhao Tang,Qinggai Wang,Amin Pu,Chenglong Xu,Peng Jia

doi:10.3389/fevo.2021.719844

Abstract

In order to investigate the motion feature of alien phytoplankton in the Bohai Bay area, this manuscript builds a two-dimensional tide hydrodynamic model coupled with a particle tracking model to simulate the alien phytoplankton movement trajectory and the diffusion processes with different specific growth rates in three major ports of Bohai Bay (Caofeidian port, Tianjin port, and Huanghua port). The results show that the movement of alien phytoplankton is mainly affected by the tidal circulation near the port, and the diffusion trend is basically consistent with the residual flow in Bohai Bay. The distribution density of alien phytoplankton is directly affected by the specific growth rate of the population and is positively related to specific growth rate. The released alien phytoplankton in the three major ports are all concentrated around the ports area. The largest distribution density is in Tianjin port, and the possibility of red tide disasters is also greatest here compared with the other two major ports. It is necessary to strengthen the monitoring of alien organisms in the port area and actively prevent alien phytoplankton from entering Bohai Bay through ship ballast water.

Highlights

Bohai Bay is an important economic belt in China, and it is located in the west of Bohai Sea, with unique geographical and important strategic position
In order to conduct a numerical simulation of the tidal current field in Bohai Bay, this study intends to build a tidal hydrodynamic numerical model of Bohai Sea with a wider coverage and provide water level for the CD open boundary required by the numerical model of Bohai Bay
Through the simulation and analysis of particle diffusion trajectory, particle number, diffusion range, and diffusion trend in Caofeidian port, Tianjin port, and Huanghua port, the following information can be obtained: the movement of alien phytoplankton is mainly affected by the tidal circulation in the port area; for different release quantities, the diffusion trend and diffusion range of alien phytoplankton in the same area are basically the same, that is, the number of alien phytoplankton will not have a significant impact on the diffusion range in the study area, but the release quantity will have a direct impact on Condition 1 Condition 2 Condition 3

Summary

Introduction

Bohai Bay is an important economic belt in China, and it is located in the west of Bohai Sea, with unique geographical and important strategic position. There are many ports in Bohai Bay, and some non-inactivated alien phytoplankton (sporangia) may be carried in with ships arriving at the port. Up to 2019, 17 species of alien phytoplankton have been found in Bohai Bay, among which 16 species belong to red tide organisms (Pu et al, 2020). Many scholars studied the ecological environment of Bohai Bay, and phytoplankton has become the focus of research. In July 2003, Cao et al (2004, 2006) detected 31 species of phytoplankton belonging to 19 genera and found red tide organisms in five sites near Luju River in Tianjin port. Wu et al (2006), by constructing a three-dimensional dynamic ecological coupling model, found that tidal current has an impact on the vertical distribution of phytoplankton and can promote In July 2003, Cao et al (2004, 2006) detected 31 species of phytoplankton belonging to 19 genera and found red tide organisms in five sites near Luju River in Tianjin port. Wu et al (2006), by constructing a three-dimensional dynamic ecological coupling model, found that tidal current has an impact on the vertical distribution of phytoplankton and can promote

Methods

Results

Conclusion