Thermal Tolerance in Tropical Versus Subtropical Pacific Reef Corals

Differences in coral thermal tolerances correspond to differenc es in the ambient temperature patterns between geographic areas, and laboratory determinations indicate that th e upper therm al limits of Hawaiian corals are 2° C less than that of tropical Pacific corals.

Abstract

Upper lethal temperature tolerances of reef corals in Hawaii and at
\nEnewetak, Marshall Islands, were determined in the field and under controlled
\nlaboratory conditions. Enewetak corals survived in situ temperatures of nearly
\n34° C, whereas 32° C was lethal to Hawaiian corals for similar short-term exposures.
\nLaboratory determinations indicate that the upper thermal limits of Hawaiian corals
\nare approximately 2° C less than congeners from the tropical Pacific. Differences in
\ncoral thermal tolerances correspond to differences in the ambient temperature
\npatterns between geographic areas.