ABSTRACT
The effects of salinity on reef corals and associated coral reef marine organisms have not been thoroughly studied, despite the importance of salinity to osmoregulation and other physiological processes necessary for reef organism survival. Reef corals and coral reefs can encounter a large range of salinities. Major coral growth and coral reef development occur in all these regions, which comprise the full range of surface salinities for the three major oceans. Coral reefs can occur where high evaporation and low precipitation and freshwater input produce normal salinities much higher than the world average. By 1968 the first recolonization of reef corals had occurred, but zoanthids occupied most of the exposed surfaces on the reef edges and flats. In reef corals the symbiotic relationship with zooxanthellae provides a convenient measure of the level of several environmental stresses, including salinity. Salinity increases or decrease within lethal tolerances can produce sublethal changes in coral reef metabolism.
