Lagrangian analysis of material transport around a shoal in Haizhou Bay

The interaction between tidal currents and the shoal topography in coastal ocean generates complex residual currents, which significantly affects material transport and ecological environments. This study examines a typical underwater shoal in Haizhou Bay, Yellow Sea, China, to explore the material transport patterns and their impact on the surrounding ecosystem. Using the Regional Ocean Modeling System (ROMS) coupled with a particle tracking model, we simulate the material transport processes and apply several Lagrangian analysis methods, including Lagrangian residual current (LRC), Lagrangian coherent structures (LCS), and average absolute dispersion (AD), to describe these patterns. The results show that the shoal contributes to the formation of local residual current vortices, resulting in the accumulation of materials and the annual aggregation of Acetes chinensis around the shoal. LCS and average AD further highlight material transport patterns including pathways and barriers around the edge of the shoal, closely aligning with the spatial distribution of A. chinensis. The present research enhances the understanding of material transport mechanisms in shoal regions and provides reference for fishery management in shallow shelf seas.