Aquaculture drives distinct patterns of planktonic and sedimentary bacterial communities: insights into co-occurrence...

Aquaculture would change the environmental condition in the lake ecosystem, affecting the structure and function of the aquatic ecosystem. However, little is known about the underlying mechanisms controlling the distribution patterns of bacterial community respond to aquaculture in water column and sediment. Here, we investigated the composition, co-occurrence patterns, and assembly processes of planktonic and sedimentary bacterial communities (PBC vs. SBC) from an aquaculture-influenced zone of the Eastern Lake Taihu, China. We found that aquaculture activity greatly influenced the diversity and composition of SBC by inducing excess nitrogen into the sediments. Meanwhile, network analysis revealed that aquaculture activity strengthened species interactions within the SBC network but weakened the species interactions within the PBC network. Aquaculture activity also increased the importance of deterministic processes governing the assembly of SBC by heightening the importance of environmental filtering, whereas it decreased the relative importance of deterministic processes within the assembly of PBC. In addition, ecological restoration with macrophytes increased the diversity of PBC and formed a more stable PBC network by increasing the number of network keystones. Overall, our results indicated that aquaculture drove distinct co-occurrence patterns and assembly mechanisms of PBC and SBC. This study has fundamental implications in the lake ecosystem for evaluating the microbially mediated ecological consequences of aquaculture.