Work

Effects of Bellamya Stocking Density on Water Quality and Bacterial Community Responses in Aquaculture Effluent

Year: 2026

Type: article

Abstract: Aquaculture effluent commonly contains residual suspended solids, inorganic nitrogen, reactive phosphorus and algal biomass, creating a need for low-cost ecological treatment strategies. This study evaluated the effects of Bellamya stocking density on water quality and bacterial community responses in aquaculture effluent. A no-snail control (CON) and four Bellamya stocking-density treatments (LD, MD, MHD and HD) were established with three independent replicates per group. Suspended solids (SS), NH₄⁺-N, NO₂⁻-N, NO₃⁻-N, PO₄³⁻-P and chlorophyll-a (Chl-a) were measured, and bacterial communities were characterized by 16S rRNA gene sequencing of the V3–V4 region. Bellamya stocking-density treatments significantly reduced NH₄⁺-N and NO₃⁻-N, while the HD and MHD treatments also showed lower PO₄³⁻-P and Chl-a. SS showed a downward tendency, whereas NO₂⁻-N tended to increase, suggesting possible transient accumulation of a nitrogen-transformation intermediate. Alpha diversity differed among treatments, and Bray-Curtis NMDS demonstrated a marked treatment-related shift in bacterial community structure (PERMANOVA R² = 0.62, P = 0.001; stress = 0.0822). At the genus level, Rhodobacter, Ahniella, Novosphingobium, Sphingobacterium and Silanimonas displayed distinct treatment responses, consistent with LEfSe-based biomarker analysis. Spearman correlation and redundancy analysis further showed that selected bacterial genera were closely associated with nitrogen, phosphorus and Chl-a gradients. Overall, Bellamya stocking-density treatments improved several eutrophication-related water-quality indicators and reshaped the effluent bacterial community. The results support Bellamya stocking-density management as a potential ecological component of aquaculture effluent management, while the microbiome results should be interpreted as community-level associations rather than direct evidence of microbial causality.

Source: Microorganisms

DOI: 10.3390/microorganisms14081813

Authors: Hao Zhu, Huichao Shen, Fan Wu, Xuan Che, Jiahua Zhang

Institutions: China Fishery Machinery and Instrument Research Institute, Chinese Academy of Fishery Sciences, Nanjing Agricultural University, Ministry of Agriculture and Rural Affairs

Language: English

Topic: Wastewater Treatment and Nitrogen Removal

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life below water, Clean water and sanitation, Zero hunger

Open Access status: gold

Estimated APC paid: $3,258