Effects of pearl gentian grouper stocking density on bacterial communities in marine aquaculture sediments
This study investigated how pearl gentian grouper stocking density alters bacterial communities in surface sediments of a fed marine aquaculture system. Outdoor enclosures were stocked with 0, 10, 15, 30, 60, or 120 fish per enclosure, with three independent enclosures per treatment. The experiment lasted 75 days; the 120-fish treatment was terminated on day 45, whereas the other treatments continued to day 75. Integrated 0-2 cm surface-sediment samples were collected with a sediment corer. Six homogenized common baseline samples were collected before treatment differentiation, followed by treatment-level samples on day 30 and on day 60; for the 120-fish treatment, the last microbial sampling was conducted on day 45. The V3-V4 region of the bacterial 16S rRNA gene was amplified using primers 338F and 806R and sequenced as paired-end 300-bp reads on an Illumina platform. These data support evaluation of density- and time-dependent changes in sediment bacterial community composition and their relationships with nitrogen cycling and nitrous oxide dynamics.