Effects of submerged macrophytes (Elodea nuttallii) on water quality and microbial communities of largemouth bass (Micropterus salmoides) ponds

Abstract

Traditional aquaculture ponds are one of the most vulnerable ecosystems; thus, ecological aquaculture is increasingly valued for its beneficial ecological properties and ecosystem services. However, little is known about ecological aquaculture of largemouth bass with submerged vegetation. Here, we designed three ecological ponds of cultured largemouth bass with submerged macrophytes (the EM group) and three ponds with traditional aquaculture (the M group) to reveal the response of water quality, and phytoplankton and bacterial communities, to submerged macrophyte bioremediation during a 90-day culture period. We observed that Cyanobacterial outbreak occurred in the M group ponds from day 7 to the end of the experiment; however, there were no Cyanobacterial blooms in the EM group ponds throughout the culture period. Compared with the M group ponds, the EM group ponds, which had submerged hydrophytes, had significantly decreased concentrations of TP, TN, and CODMn, but significantly increased DO concentrations throughout the experimental period. Moreover, ecological aquaculture with submerged macrophytes showed strong effects on the phytoplankton and bacterial community compositions. In particular, the M group ponds had higher phytoplankton density and mainly included Cyanobacteria, whereas the EM group had lower phytoplankton density and mainly included Chlorophyta. Moreover, higher alpha diversity, as determined by Ace and Simpson index values, was detected for bacterial communities in the EM group ponds. Furthermore, PCoA clearly grouped the bacterial communities according to the two culture modes throughout the culture period. These results indicate that ecological aquaculture with submerged macrophytes can improve water quality, control Cyanobacterial blooms, and affect the diversity and composition of bacterial communities. These valuable effects seem to be beneficial and consistent to maintaining aquaculture ecosystem stability.

Effectiveness of a novel compound microbial agent for water quality and the gut microbiota of Micropterus salmoides

“…In this study, a-diversity and b-diversity analysis of the microbiota showed that compared to the control and SMA treatment group, CMA treatment group exhibited higher diversity among the microbial community, particularly of chao1 index at 32 d (17.58% higher than that of the control group), indicating the effectiveness of CMA treatment in improving species diversity of water microorganism and regulating the structure of water flora. There was a strong correlation between water quality and the species diversity of water microorganism, contributing to the stability of aquaculture ecosystem for M. salmoides (Nie et al, 2022). Simultaneously, LEFSe analysis demonstrated that the relative abundance of Bacteroides was higher in the control group at 32 d (p value < 0.05), indicating that compared to SMA and CMA treatment group, the aquatic environment of the control group has undergone severe eutrophication (Wagner and Loy, 2002).…”

Effects of Different Submerged Macrophytes on the Water and Sediment in Aquaculture Ponds with Enrofloxacin Residues

“…The data were analyzed on the free online platform of Majorbio I-Sanger Cloud Platform (cloud.majorbio.com (accessed on 20 November 2019)). The detailed analysis methods in this section were introduced in Nie et al [21].…”