Microbial community shift on artificial biological reef structures (ABRs) deployed in the South China Sea

Abstract

Many Artificial Reefs (ARs) have been used worldwide for marine habitat and coral reef restoration. However, the microbial community structure that colonize the ARs and their progressive development have been seldom investigated. In this study, the successive development of the microbial communities on environmentally friendly Artificial Biological Reef structures (ABRs)R made of special concrete supported with bioactive materials collected from marine algal sources were studied. Three seasons (spring, summer and autumn), three coral reef localities and control models (SCE) without bioactive material and (NCE) made of normal cement were compared. The structure of the microbial pattern exhibited successive shifts from the natural environment to the ABRs supported with bioactive materials (ABAM). Cyanobacteria, Proteobacteria, and Planctomycetota were shown to be the most three dominant phyla. Their relative abundances pointedly increased on ABAM and SCE models compared to the environment. Amplicon Sequence Variant (ASV) Richness and Shannon index were obviously higher on ABAM models and showed significant positive relationship with that of macrobenthos than those on the controls and the natural reef (XR). Our results offer successful establishment of healthy microbial films on the ABR surfaces enhanced the restoration of macrobenthic community in the damaged coral reefs which better understands the ecological role of the ABRs.

Biodeterioration and Chemical Corrosion of Concrete in the Marine Environment: Too Complex for Prediction

“…The lower microbial diversity on its surface indicates the slightly toxic nature of this cement to marine bacteria, as previously shown for bacteria in groundwater stored in concrete or earthen ponds, the former being lower in diversity and abundance [114]. Indeed, concrete has been described as having especially deleterious consequences on biodiversity in all aquatic ecosystems [115]; this concords with research suggesting that a relatively mature microbial biofilm on concrete in the marine environment is somewhat generic, differing little from normal structural concrete composition [39][40][41].…”

“…is unknown, although there is no evidence of this from studies on the better-studied sewer pipe corrosion. Recently, however, there have been publications indicating that the initial microbial population attaching to concrete in the marine environment changes with time to produce a common "generic" concrete biofilm [39][40][41]. Earlier results had indicated this possibility.…”

“…Ref. [41] used metagenomics to study the bacterial colonization of three types of cement for use in artificial reefs around the coral reefs off Weizhou Island, China, sampling over three concurrent seasons. Initially, Cyanobacteria dominated all the concrete samples, with Proteobacteria also common.…”

“…Ref. [41] found that the standard, unmodified cement in artificial reefs showed lower biodiversity than the other two types of cement, which contained bioactive materials. The lower microbial diversity on its surface indicates the slightly toxic nature of this cement to marine bacteria, as previously shown for bacteria in groundwater stored in concrete or earthen ponds, the former being lower in diversity and abundance [114].…”