​TITLE: Multiple stressor interaction effects of nutrient enrichment and oil pollution on Red Sea     benthic recruitment

 ADVISOR:  Prof. Michael Berumen

 DATE:  Monday, 5 November

 TIME:  10 am

 LOCATION: Building 2 (seaside) · Level 5 · Room 5220

ABSTRACT: Increases in coastal development along the Saudi Arabian coast may increase eutrophication due to impacts of human population and also oil pollution from increased shipping traffic and refinery activity. The risk of oil pollution combined with increasing eutrophication due to coastal development provides a clear stressor interaction which is vastly understudied. Individually, these stressors are known to negatively impact coral reproduction, recruitment, and growth. This study focuses on reef settlement and recovery following experimentally-simulated disturbance scenarios. Carbonate recruitment tiles were placed on the reef and exposed to four treatments: control, nutrient enrichment with slow-release fertilizer, tiles soaked in crude oil, and a combination treatment of nutrient enrichment and oil-coated tiles. At periods of 3, 6, 9, 14, and 17 weeks, tiles were collected to classify the settled community and measure oxygen production. Oil, nitrate, and phosphate were the biggest determining factors predicting settlement and oxygen production of the different treatments. The oil treatment had the least overall settlement and oxygen production, whereas the nutrient treatment had the most turf algal recruitment and oxygen production. The combination treatment had an antagonistic effect on algal growth: the nutrients facilitated growth on the otherwise toxic oiled tiles.