The mission of preserving the reef ecosystem at Hanauma Bay was the reason, 56 years ago, for creating the state’s first marine life conservation district in the first place.

And now research by the Hawaii Institute of Marine Biology at the University of Hawaii-Manoa appears to underscore both the wisdom of establishing the Hanauma Bay Nature Preserve, and the realization that environmental impacts of climate change will be severe and require adaptation.

Research was conducted over five years, including the period when the shutdown of tourism provided a stark comparison of the pre-pandemic period of high shoreline traffic and a rare time when there was hardly any use at all.

Broadly, conservation has largely succeeded in allowing the colorful reef species populations to recover over time, resulting in the bay becoming a favorite spot for snorkelers who can easily see the colorful array of living creatures just below the surface.

The future doesn’t look quite so sunny. Most startling was the projection that by 2030, most of the bay’s sandy beach would be underwater, as a result of rising seas.

The full compilation of this “biological carrying capacity” data won’t be released until the end of this month, according to one of the principal authors from the institute, Ku‘ulei Rodgers.

But it’s already clear that some contingencies are needed, and soon, if the resource is to be enjoyed, sustainably, in perpetuity.

What has been released are projections that sea levels will rise a half-foot at a minimum. Compounded by the highest tide predicted, that would result in 88% of the bay’s sandy beach being submerged in seven years.

Part of the research, a “social carrying capacity study,” was published in April in the journal Tourism Recreation Research.

The social study was conducted following a nine-month closure forced by COVID-19 travel restrictions, measuring the impact of the human traffic in one of Oahu’s most popular natural attractions. It evaluates how visitors interact with each other, using surveys to gauge crowding perceptions and reactions to recreational activities, and it assesses the impact on the ecosystem itself.

Questions about crowding showed that most visitors did not find the area so crowded as to affect their experience, but just over half did say that the preserve can’t accommodate any increase. Many said the online reservation system prevented crowding.

In terms of visitor behavior, “Look but do not touch” apparently was not a rule they observed. Of those surveyed, 74% reported witnessing other visitors making contact with the reef. Some saw visitors kicking, grasping and sitting on coral.

That may seem to suggest that reducing the number of visitors would help in curbing potential damage to the ecosystem. But the survey results indicate that most visitors responded well to the mandatory educational video that was instituted in 2002, a step up from the previous use of mere signs, displays and an information booth.

The social capacity challenge, then, should be less about reducing crowds and more about ensuring that those on site understand the environment. “Increasing visitor educational opportunities in contrast to reducing capacity limits was determined to be effective in addressing management concerns,” according to the study.

That said, the release of details on the prospect of an inundated beachfront certainly bear watching. Such changing conditions will demand coping strategies such as reconfiguring the public areas — or the calendar, setting when the park should be open.

It’s imperative to start making those plans now: 2030 is not far away.