Monitoring the Impact of Offshore Aquaculture on Ambient Water Quality in the Red Sea

The Saudi Arabian government has announced an economic development plan (Vision 2030) to invest in a range of industries across the Kingdom, one of which is aquaculture. In the face of a likely increase in Red Sea fish... [ view full abstract ]

The Saudi Arabian government has announced an economic development plan (Vision 2030) to invest in a range of industries across the Kingdom, one of which is aquaculture. In the face of a likely increase in Red Sea fish farming, we investigated the impacts of offshore aquaculture on the coastal water quality of the Red Sea by monitoring the water column surrounding a Saudi Arabian offshore fish farm on the southcentral coast of the Red Sea. Water quality parameters around the fish farm as well as organic loading on a nearby coral reef were measured seasonally to determine the impacts of fish farm effluent on the surrounding environment. Water column properties differed up-current and down-current from the fish farm, with bacteria and dissolved inorganic phosphorous and nitrogen concentrations showing patterns of enrichment, and dissolved oxygen concentrations being lowered, close to and down-current of the fish farm. These signals of enrichment were mainly observed close to the farm (within several hundred meters), and decreased with distance from the farm. We are in the process of using the data from our sampling efforts as input parameters for an aquaculture modeling software to model the fate and transport of fish farm effluent. Through this field study, we assess the spatial extent and magnitude of organic enrichment caused by a Red Sea fish farm, with the goal of understanding and predicting the potential impacts of future offshore aquaculture development in Saudi Arabia on the water quality of this tropical, oligotrophic environment.