English abstract
The Arabian Gulf offers a unique environment to study the attributes that shape up the spatiotemporal distribution of marine biofouling microbial communities. The growth of biofouling community relies on complex interactions of biological, chemical and physical factors, which are yet to be comprehensively studied. This research compared the spatial and temporal variations of biofouling microbial communities in four onshore marinas located at the Arabian Gulf; Al Mouj and Bandar Rowdha in Oman and Salmiya and Fintas in Kuwait. Acrylic panels were deployed for a total period of 6 months and biofilms were collected once every month. The macrofoulers were identified and their coverage was estimated using ImageJ software. The bacterial densities were numerated by DAPI staining and chlorophyll a content was quantified to account for the abundance of total phototrophs. Bacterial community compositions on all panels and at all time-points were analysed using high throughput sequencing technology (i.e. Illumina MiSeq) for 16s rRNA. The results suggested that the Omani locations had a much higher diversity of macrofouling communities than the Kuwaiti locations. In contrary to Kuwaiti marinas, the Omani marinas had a higher total biomass and bacterial counts, but lesser Chlorophyll a. Cluster analysis showed a strong spatial partitioning of bacterial community datasets at a large-scale between Oman and Kuwait, and at a small-scale between Al Mouj and Bandar Rowdha. Aphaproteobacteria was the most dominant class in Omani locations whereas Gammaproteobacteria were found as the dominant group in the Kuwaiti marinas. The bacterial communities had a dynamic structure with significant temporal shifts affiliated to seasonality as well as, environmental perturbations. The data supports the statement that biofouling is a "hot spot" for ecologically threatening species. Therefore, optimizing management strategies to control biofouling could rely on seasonality and in-situ attributes of the targeted location.
