Effect of river discharge on spawning grounds around the Yellow River Estuary

The Yellow River discharge is unevenly distributed on a time scale, and the river discharge into the sea reached its peak in the past 20 years in 2021. River discharge has a great impact on the temperature and salinity distribution and fish spawning grounds around the Yellow River estuary and Laizhou Bay. This paper analyzes the variation trend of the Yellow River discharge in the past 20 years, and simulates the temperature and salinity distribution around the Yellow River estuary from 2020 to 2022 through a numerical model. The effects of river discharge on the distribution of ocean temperature, salinity and spawning grounds were studied. According to the temperature and salinity of the sampling location, the temperature of main spawning grounds is about 16 degree celsius, and the salinity range is 30 to 30.5 psu (practical salinity scale). Key spawning grounds are more distributed in the peripheral areas where the Yellow River water is mixed and has less impact. Meanwhile, the key spawning grounds are far away from the main axis of the freshwater diffusion. The key spawning grounds will change with the Yellow River discharge diffusion structure, and moved westward in 2022.