Assessing Human-Induced Coral Reef Disturbances From Visitors at Hanamua Bay Nature Preserve

Abstract

It has been noted in many research papers that regions with high snorkeling and diving activity damages coral reef ecosystems. I investigated the effects of visitor snorkeling density, and the number of times snorkelers physically disturbed the reef. Four plots were designated for bimonthly monitoring, where the number of snorkelers entering each plot and their interaction with the reef was recorded. Coral health was qualitatively observed, and the surface area of the coral tissue was quantitatively measured. My results show a direct relationship between snorkeling density and the number of disturbances. However, there is no evidence of visitor density and coral health impairment. There was no coral breakage or abrasions from snorkelers during the data collection period, possibly a result of low coral cover across the bay, limited branching morphology, and/or species with high skeletal strength due to historical disturbances from higher water motion and extensive visitors. Corals in each of the plots experienced tissue loss mainly from preexisting lesions or tissue damage; the causation of the previous coral injury is unknown. Future management actions in Hanauma Bay could limit the number of visitors and occurrence of reef disturbances to potentially reduce tissue loss and promote coral recruitment.