Recovery of the benthic bacterial community in coastal abandoned saltern requires over 35 years: A comparative case study in the Yellow Sea

[Display omitted] •Bacterial communities in abandoned salterns did not fully recover after 35 years.•Proteobacteria was a crucial taxon in the microbial community during the recovery period.•A time lag between the recovery of the sediment environment and bacterial community was observed.•Factors affecting the bacterial community during saltern recovery are complex and unclear.•Sediment bacterial communities served as a sensitive index for evaluating the solar saltern restoration. Salt is an essential nutrient for humans, and salterns exist worldwide. Although the construction of salterns has stopped and typical salterns are now mostly abandoned, there has been no research on the ecological recovery of the abandoned salterns. Here, we analyzed the bacterial diversity and community structure in three pairs of abandoned salterns that have undergone 1–35 years of natural restoration and tidal flats to determine the recovery time and process. Partial 16S rRNA sequences were amplified and sequenced to investigate the biodiversity and structure of the bacterial community in sediments collected from abandoned salterns and adjacent natural tidal flats (viz., controls) in the Yellow Sea. The most abundant microorganisms across locations were found to be members of Proteobacteria, ranging from 45 to 72%, which was also a crucial taxon in the bacterial recovery process. The benthic bacterial community of the salterns showed time-dependent recovery, as demonstrated by the similarity between the salterns and controls. Indeed, dissimilarities between bacterial communities were significant for the saltern that had been abandoned for one year, according to ANOSIM (R = 1.0, p