Effects of three common pollutants on the gut microbiome and behaviour of freshwater fish

Globally freshwaters are the world?s most endangered habitats. Oman has relatively few freshwater ecosystems but they are biodiversity hot spots, home to complex communities of fishes, frogs and fish, and supporting diverse terrestrial species including migratory wading birds and many desert mammals and reptiles. Healthy wadis are also at the heart of Oman?s ambition to be a global leader in ecotourism. Oman?s wadis are also closely integrated with traditional Omani culture and agriculture. The close proximity between the freshwater ecosystems and human activities also poses risks to wadi inhabitants through the direct and indirect discharge of chemicals, pharmaceuticals and other wastes enters these aquatic habitats. Pharmaceuticals can contaminate surface and groundwater when they are excreted in human waste and discharged via the sewerage and septic systems. As these drugs contain potent bioactive ingredients they can pose serious hazards to animals they are incidentally exposed. Over 600 different pharmaceuticals have now been detected in surface waters worldwide. In recent years it has been demonstrated that a healthy gut flora of bacteria and fungi is essential for health in humans and depleted flora is associated with multiple chronic physical and psychological illnesses. We are only beginning to understand the importance of the gut microbiome in fish and how it relates to their overall health and behaviour. In this study we will investigate the effects of three pharmaceuticals commonly detected in surface waters on the intestinal flora of fish and correlate changes to effects on the fish?s physiology and behaviour. This study will show if pharmaceutical contamination in ground and surface waters pose a threat to the native wadi fauna and lead to recommendations for better management of sewerage disposal if hazards are discovered.