Guangdong Provincial Key Laboratory of Fishery Ecology and Environment and Key Laboratory of Open-Sea Fishery Development, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou 510300, PR China. Electronic address: [Email]
Mariculture is known to contribute to oxygen depletion, pH decline and accumulation of nutrients and organic matter in sediments. However, studies on the bacterial vertical distribution of mariculture area are very limited. The bacterial abundance in the non-culture site (3.8 ± 0.8 × 109 copies g-1) was significantly higher than that in the three mariculture sites (1.2 ± 0.2 × 109 copies g-1), and bacterial diversity in the non-culture site was significantly higher than that in fish cage-TF (p < 0.05). The vertical distribution profiles of bacteria in non-culture and oyster culture sites were similar but very different from that of fish cage-TF. In addition, significant downward trends in bacterial abundance and diversity were observed as sediment depth increased (p < 0.05), and the most relevant environmental factors were moisture content, total nitrogen, total organic carbon and carbon/nitrogen. The dominant bacterial phyla in sediment were Proteobacteria, Chloroflexi and Bacteroidetes.