Planktonic bacteria in white shrimp (Litopenaeus vannamei) and channel catfish (Letalurus punetaus) aquaculture ponds in a salt-alkaline region.

Aquaculture in salt-alkaline regions is encouraged in China, and culture of many aquatic species has been introduced into these areas. In this study, we cultured two species, white shrimp (Litopenaeus vannamei) and channel catfish (Letalurus punetaus) separately in aquaculture ponds in a salt-alkaline region in northwest China and assessed the impacts of the aquaculture operations on the planktonic bacterial community in the culture ponds. Culture of both species decreased the planktonic bacterial diversity and altered the bacterial community structure in the aquaculture ponds compared with the source water. Among the 10 dominant bacterial phyla, 8 were significantly correlated with environmental parameters; the exception was Actinobacteriota, the most dominant phylum, and Firmicutes. Proteobacteria and Bacteroidota abundances showed significant positive correlations with alkalinity, whereas Patescibacteria, Cyanobacteria, Planctomycetota, and Verrucomicrobiota abundance were positively correlated with salinity. Linear regression analysis showed that alkalinity was positively correlated with bacterial beta diversity and salinity was negatively correlated with that. In addition, white shrimp aquaculture significantly lowered the alkalinity, which suggests that culture of this species in inland salt-alkaline regions is a potential dealkalization solution.