Seasonal Succession of Bacterial Communities in the Land-Based Container with Recycling Water Aquaculture System

Abstract

The land-based container with recycling water aquaculture system (C-RAS) has gained popularity in China due to its water conservation and pollution reduction capabilities. However, there is a dearth of theoretical research on this subject. In this study, water from Koi-cultured container and three-stage eco-ponds was sampled over three seasons and then the bacterial communities were analyzed. The findings of this study indicate that the implementation of three-stage eco-ponds significantly enhances water quality. Specifically, during the summer season, eco-ponds exhibit the highest removal efficiencies of total nitrogen and total phosphorus in comparison to other seasons. During winter, the bacterial communities' operational taxonomic units, diversity, and richness experience a substantial decline. The system was dominated by Proteobacteria, Bacteroidota, and Actinobacteriota phyla. The lower relative abundance of Actinobacteriota and Cyanobacteria elucidated the reason for the lower off-flavor compounds in container-cultured fish compared to pond-cultured fish. The bacterial community was significantly influenced by water temperature and pH, as revealed by canonical correspondence analysis. These findings establish a fundamental basis for the development of a healthy and sustainable C-RAS technology.