New study demonstrates the impacts of multiple stressors on reef-building corals

In a new study, scientists at AOML and the University of Miami’s Cooperative Institute for Marine and Atmospheric Sciences (CIMAS) demonstrated how some genotypes of the reef-building coral Acropora cervicornis (Staghorn Coral), listed on the Endangered Species Act, proved resilient when exposed to high nutrient levels or disease, but not when the two stressors were combined.

In the Experimental Reef Lab, ten key Acropora cervicornis genotypes – corals of the same species with slightly different genetic makeups – were evenly distributed across independently-controlled tanks. Half of the tanks were exposed to elevated levels of nitrogen (specifically, in the form ammonium) for six weeks, while the other half served as a control group under normal conditions.

Initially collected from three coral nurseries at Florida’s Fish and Wildlife Conservation Commission (FWC), Coral Restoration Foundation (CRF), and the University of Miami, scientists at AOML monitored how these different genotypes responded to nutrient concentrations both typically seen on reef ecosystems and concentrations considered excessive – usually due to nutrient runoff and pollution.

After the six weeks, each coral was exposed to one of two treatments: one being a placebo and the other a coral tissue infected with a white disease found in coral outplants.

With each A. cervicornis genotype then exposed to all combinations of normal or heightened nutrient levels and disease or no disease simultaneously, scientists at AOML analyzed the fragments daily, examining any tissue loss, and overall survivorship. Continue reading

Related publications (Palacio-Castro et al., 2025).