Trophic response of corals to large amplitude internal waves

The trophic response of the scleractinian coral Pocillopora meandrina (Dana, 1846) to large amplitude internal waves (LAIW) was investigated in the Andaman Sea. Corals living on the western sides of the Similan Islands (Thailand) exposed to LAIW showed significantly higher biomass and protein content than sheltered corals on the eastern sides. LAIW-exposed corals were also more heterotrophic, displaying lower delta C-13 ratios in their tissues and higher rates of survival in artificial darkness compared to sheltered counterparts. Heterotrophic nutrition in concert with photosynthesis leads to higher energy reserves in corals from LAIW-exposed reefs, making them more resilient to disturbance. As these differences in trophic status are due to LAIW-enhanced fluxes of organic matter, LAIW may play an important role in supporting coral metabolism and survival in these monsoon beaten reefs.