Balancing visitor enjoyment, marine conservation at Hanauma Bay

Recently implemented management policies at the Hanauma Bay Nature Preserve have improved marine conservation efforts and visitor enjoyment, and drawn more Hawai‘i residents to this popular O‘ahu snorkeling spot, according to a new study published by a University of Hawai‘i (UH) at Mānoa researcher and students. 

Ku‘ulei Rodgers, a researcher at the Hawai‘i Institute of Marine Biology (HIMB) in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), led a social carrying capacity study upon reopening of Hanauma Bay, following a nine-month COVID-19 closure due to travel restrictions. 

Social carrying capacity is defined as the type and level of visitor use that can be accommodated while sustaining acceptable resources and social conditions that complement the purpose of the park. To assess this, Rodgers and study co-authors distributed surveys to Hanauma Bay visitors that included questions about demographics, recreational activities, crowding perceptions, and educational availability. Additionally, visitor activity photos and counts were evaluated in context with survey responses. 

More Hawai‘i residents, positive experiences

Local resident use of the Hanauma Bay Nature Preserve in the previous social carrying capacity surveys in 2005 reported 3% of visitors were Hawai‘i residents. This latest research established a significant increase–13% of all visitors were local. 

“It was a gratifying revelation that the presence of Hawai‘i residents at Hanauma Bay has increased so substantially,” said Rodgers. “The number of locals visiting the park had been declining for decades since the 1990s when over 4 million visitors per year deterred residents from enjoying the marine park.”

The authors suggest the increase can be partially attributed to early entry hours, an entry fee waiver, and the bypassing of the mandatory viewing of the video when previously viewed. Other recent administrative changes include an online registration and payment system, which has greatly reduced the lines and wait times throughout most of the day.

Further, the survey revealed overwhelmingly positive responses regarding visitor satisfaction. Over 95% of all respondents, residents and tourists, were highly satisfied with their experience and did not perceive crowded conditions.

Conserving ecosystem health

Previous research on the ecological effects of people visiting Hanauma Bay has shown increased visitors can cause shifts in fish and coral distribution, fish density can decrease in areas of high snorkeling activity, and reef trampling can have widespread negative effects on ecosystem health. To address these human impacts on marine life, a mandatory educational video detailing proper reef etiquette was introduced to the Nature Preserve in 2002.

As part of the recent study, perceived visitor contact on the reef from surveys was compared to observed tracks of snorkelers. Reef contact was perceived by the majority of visitors responding to the surveys (74%), while in water observations recorded reef contact 53% of the time. There was an average of one disturbance for every two visitors tracked. However only 3% of interactions were with coral since coral cover is extremely low in high traffic areas.

Balancing economics, marine health, visitor experience

Tourism is the number one contributor to the state’s economy. Over 220,000 local jobs are generated within the tourism industry and over two billion dollars in State of Hawai‘i tax revenues are generated by visitors. 

“Successful management policies that include social carrying capacities should align with biological carrying capacities to balance the health of the ecosystem with a positive experience for visitors,” said Rodgers. “Information derived from this study will assist management in developing adaptive strategies that can incorporate that balance to assure visitor enjoyment and marine conservation.”  

In addition to the extensive biological and social carrying capacity studies that Rodgers and her team have conducted, they are currently incorporating physical carrying studies to understand efficiency and spatial components of Hanauma Bay. They also plan to continue environmental and biological monitoring of marine life, including coral bleaching surveys and changes in fish communities, to inform conservation efforts.