ECOLOGICAL IMPACTS OF A RESILIENT CORAL IN HONOLULU HARBOR

Harbor Porites is an unusually resilient coral species of uncertain origin and taxonomy found in high abundance in Honolulu Harbor. The harbor is an inhospitable environment for most corals, with high levels of pollution and human activity. Harbor Porites is of particular interest to conservationists, both for its ability to colonize hostile environments and encourage reef growth as a pioneer species, and for the threats it may pose as a dominant species that may invade reefs beyond the harbor. This project aims to investigate the ecological impacts of this species by characterizing its competitive abilities. Fragments of harbor Porites were placed in direct contact with fragments of five other coral species and were observed for signs of aggression along the zone of contact, noting mesenterial filaments, sweeper tentacles, and tissue mortality. Preliminary results categorize harbor Porites as moderately aggressive, dominating over some species but subordinate to others. Further experiments and field surveys will investigate whether the presence of this species may promote reef growth by encouraging larval settlement of other corals, and whether its dominance in the harbor may limit the growth of algae and sponges that may otherwise prevent coral growth. Corals form the basis of some of the most ecologically, culturally, and economically significant ecosystems on Earth, valued at over $2 trillion. With coral reefs degrading under anthropogenic sources of stress, factors underlying reef resilience are of particular interest to managers and policymakers.

Primary Presenter: Madelief Schelvis, University of Hawaiʻi at Mānoa (madelief@hawaii.edu)

Authors:

Madelief Schelvis, University of Hawaiʻi at Mānoa  (madelief@hawaii.edu)

Robert Richmond, University of Hawaiʻi at Mānoa  (richmond@hawaii.edu)