Effects of Penaeus japonicus stocking density on water quality and bacterial community structure in water in an integrated multi-trophic aquaculture (IMTA) system

Abstract

The relationship between water quality and bacterial composition may determine the sustainability level in an integrated multi-trophic aquaculture (IMTA) system. In this study, the effects of different shrimp stocking densities on water quality and bacterial community structure were studied in a sea cucumber-shrimp-crab-fish IMTA system. The results showed correlations between bacterial community structure and water quality parameters (dissolved oxygen, salinity, pH, ammonia nitrogen, nitrite nitrogen, and phosphate phosphorus) under different stocking densities of Penaeus japonicus. Temperature, salinity, nitrite nitrogen, ammonia nitrogen, and phosphate phosphorus were significant factors (p < 0.05) influencing the bacterial community in the samples. Nitrite nitrogen showed the greatest effect on bacterial community diversity and richness. Flavobacteriaceae and Cryomorphaceae play important roles in the denitrification process, and these bacteria were significantly more abundant in low-density ponds than in high-density ponds. This study provides practical knowledge on shrimp stocking density management and its effect on IMTA system biosecurity.