BIOFILM DYNAMICS AND SUCCESSION ON ARTIFICIAL REEFS

Primary microbial settlement on ECOncrete® tiles in Red sea was studied. ECOncrete® Company produces concrete which is designed to enhance settlement of native sessile organisms in order to reduce negative ecological impact of foreign materials introduced to the marine environment such as artificial reefs. The present study tracks the dynamics and succession of biofouling and biofilm formation. Samples were measured after 24 hours, a week, month and three months. 16S rRNA libraries were sequenced using the Illumina MiSeq platform and data were analyzed using Qiime. Each sample (~ 20,000 OTUs) displayed few dominant groups. Vibrio was found to compose approximately 5% of observed OTUs during the first stages of microbial adhesion. Samples from one week to three months revealed substitution of Vibrios by Cyanobacteria. Pseudoaltromonas which is known as resident of many coral species was observed at the beginning of adhesion up to 24 hours and decreased with a time. Red algae of class Florideophycea, which are well known as a sign for healthy reef development, was dominant after three months. These results will allow a better understanding of the biofouling and biofilm dynamics among primary microbial settlers that provide the foundation for sessile native organisms to inhabit this environment.