Bacterial community and environmental factors associated to rivers runoff and their possible impacts on coral reef conservation

Abstract

Rivers potentially conduct important components as result of anthropogenic stressors for coral reefs. Molecular techniques are increasingly being used for monitoring biological and chemical monitoring of rivers and reefs. Here, we use PhyloChips™ to process surface water samples collected along two rivers and associated reefs in an environmental protection area in northeastern Brazil. Our results indicate that a significant part of Operational Taxonomic Units (OTUs) identified were able to survive the transition from freshwater to seawater, several of them belonging to genera implicated in human pathogenesis. The BBC:A ratio and functional prediction suggests that both study rivers are subject to fecal contamination and xenobiotics input and that the bacterial communities were more homogeneous in these environments. We suggest that protection actions adopted for reefs should be broadly extended to the surrounding environment, and that other bacterial group (besides cultivable coliforms) should be included in routine water quality monitoring.