During an unusual cold-water event in January 2010, reefs along the Florida Reef Tract suffered extensive coral mortality, especially in shallow reef habitats in close proximity to shore and with connections to coastal bays. The threatened staghorn coral, Acropora cervicornis, is the focus of propagation and restoration activities in Florida and one of the species that exhibited high susceptibility to low temperatures. Complete mortality of wild staghorn colonies was documented at 42.9% of donor sites surveyed after the cold event. Remarkably, 72.7% of sites with complete A. cervicornis mortality had fragments surviving within in situ coral nurseries. Thus, coral nurseries served as repositories for genetic material that would have otherwise been completely lost from donor sites. The location of the coral nurseries at deeper habitats and distanced from shallow nearshore habitats that experienced extreme temperature conditions buffered the impacts of the cold-water event and preserved essential local genotypes for future Acropora restoration activities.