Andi Haas

I study changes in coral reef ecosystems as a consequence of human influence. The infamous bleaching of coral, due to the loss of symbiotic algae under warm seawater conditions is well known. A lesser-known threat for corals comes from other algae that can emerge if there is an excess of nutrients in the water – for example from wastewater or pollution. Most algae release sugars that provide a ‘fast-food’ source for bacteria. Subsequently, the entire balance shifts and ultimately, algae and other non-calcifying organisms like sponges emerge that can decompose the calcium carbonate of the corals. In a comparative study of coral reefs across the pacific we could see clear evidence of this fast-food effect.