The Shandong Peninsula as a geographical barrier: Divergence of the bartail flathead Platycephalus indicus resources and associated environmental factors in the Bohai Sea and Yellow Sea

Abstract

Appropriate resources and environmental conditions are essential for the survival and development of living organisms. The Shandong Peninsula is situated between the Bohai Sea and Yellow Sea, offering a complex geographical environment with rich fisheries. This study aims to explore the divergent impact of the Shandong Peninsula on resource dynamics by analyzing the differences in environmental factors and distribution patterns of an important fishery resource, the bartail flathead Platycephalus indicus, between the Bohai Sea and Yellow Sea. We depicted the spatial driving effects of environmental factors on the bartail flathead resources using the generalized additive model (GAM). The results indicate that the surface temperature, as well as the surface and bottom salinity, of the Yellow Sea, are generally higher than those of the Bohai Sea. Conversely, the bottom temperature and Chlorophyll A concentration of the Bohai Sea are higher than those of the Yellow Sea. A distinct seasonal pattern was illustrated in the surface temperature, bottom temperature, and Chlorophyll A concentration. The surface and bottom temperatures displayed coherence, contrary to the Chlorophyll A concentration, which exhibited an inverse trend to temperature. And the bottom temperature exhibits a two-month delay relative to the surface temperature. The salinity levels at the surface and bottom remained fairly constant over the year. The abundance of bartail flathead varies seasonally and reaches its lowest point in spring. It thrives in the Bohai Sea during summer, while it predominates in the Yellow Sea during winter. In autumn, it is plentiful in both seas, with different distribution centers. The generalized additive model indicates that the optimal distribution area for bartail flathead is located between 120°E and 122°E. Bartail flathead abundance has a significant positive correlation with surface temperature, bottom temperature, and surface salinity, however, it has a significant negative correlation with bottom salinity and Chlorophyll A concentration. Depth does not show any significant correlation with bartail flathead abundance. These findings can serve as the basis for developing measures to protect crucial marine fishery resources and enhance fishery management practices.