Plankton community diversity-driven mutualism in medium-salinity ponds enhances growth of pacific white shrimp Penaeus vannamei

Abstract

The high-salinity pond aquaculture model has been widely accepted for its advantages in utilizing saline-alkali soil and enhancing shrimp quality. Plankton communities play critical roles in aquaculture ecosystems, but their responses to salinity gradients and impacts on Penaeus vannamei growth remain underexplored. This study investigated plankton dynamics, environmental drivers, and shrimp performance across three salinities in Binzhou, China. Throughout the aquaculture process, phytoplankton community composition showed a clear succession pattern, shifting from diverse species to a Skeletonema-dominated structure with gradually increasing species abundance. In contrast, zooplankton diversity and abundance decreased over time. Redundancy Analysis (RDA) and Variance Partitioning Analysis (VPA) revealed that salinity, temperature, and dissolved inorganic nitrogen (DIN) were closely linked to dominant species. The study elucidated the functional traits of plankton communities mediated by salinity, showing that medium salinity (38 ± 3.58 ‰) fostered a mutualistic diatom-copepod relationship. This mutualism enhanced dissolved oxygen and supported 80.2 % higher shrimp biomass compared to high-salinity systems. These findings provide insights into the ecological interactions between plankton and environmental factors in aquaculture systems and offer guidance for optimizing shrimp farming practices, such as maintaining medium salinity levels to foster a balanced plankton community, which can enhance water quality and support healthy shrimp growth.

Keywords: Aquaculture ponds; Environmental factors; Pacific white shrimp Penaeus vannamei; Plankton community; Salinity.