A mesocosm experiment was conducted to determine the effects of nutrient enrichment on competitive interactions between a hard coral, a green alga, and a sea anemone. In the low‐nutrient controls, abundances of the green alga, Codium edule , and a sea anemone, Mesactinia genesis , remained low, and they coexisted with the live or dead scleractinian coral, Acropora muricata . Combined nitrogen and phosphorus additions markedly...