What will we do about Hawaiʻi’s disappearing shorelines?

HONOLULU (KHON2) — Shorelines are beginning to disappear around the world.

The University of Hawaiʻi and the Surfrider Foundation have both found some disturbing prospects for Hawaiʻi’s coveted beaches.

The Surfrider Foundation has identified five US areas that display the varying threats of our coastlines. One of those was Oahu’s North Shore.

In their study, Surfrider Foundation discovered that 75% of The North Shore’s beaches are rapidly eroding. The erosion is threatening homes, roads, peoples’ ability to enjoy the beaches/waves and the local economy. 

“In an effort to proactively protect accelerated beach loss and improve our beaches and coastlines, the Surfrider Foundation is advocating for nature-based solutions and working to address coastal resilience challenges,” said a spokesperson for Surfrider. 

In addition to these findings, UH did a five-year study in which a research team explored the impacts of sea-level rise on the Hanauma Bay Nature Preserve.

In evaluating the biological, physical, and social carrying capacities of this pristine natural destination, the team found that 88% of the preserve’s usable beach will be underwater by 2030.

“The predictions of the extent that sea level will impact the usable area at Hanauma Bay was eye-opening,” said Kuʻulei Rodgers, researcher at HIMB. “It will assist management in preparation and to develop recommendations, other alternatives and solutions.”

An aspect of the research that impacted findings was an examination of how tourism is impacting fish populations.

They found two significant points of data:

1. Some fish has less of a flight instinct when it comes to humans approaching them.
2. Fish became more diverse when there were no tourists (like during the pandemic), and fish become less diverse when there are copious amounts tourists, as with daily operations of HBNP.

They also found that tourism around HBNP is changing:

1. Tourism from Japan dropped from 25% in 2005 to less than 1% in 2022.
2. There was an increase in Hawaiʻi residents visiting from 3% in 2001 to 13% in 2022.

The team said that tourism at HBNP has decreases from 4 million annually to 500.,000 annually due to

1. closing HBNP two days per week.
2. a reservation system.
3. increased fees.
4. effective management strategies.

“During the pandemic closure, the water clarity was 56% clearer as compared to prior to the closure,” said a spokesperson for the team. “Following the reopening of HBNP at 25% visitor capacity, the water clarity decreased by 30%.

Another issue that is at our front door is the move to take sand from an ancient leeward side beach of Oahu to be take to replenish the beach in Waikīkī.

The issue with the Waikīkī Beach dates back over a century when businesses began building seawalls.

In a written report in July 2023 that was provided to board members for the Department of Land and Natural resources, the Office of Conservation and Coastal Lands stated the following information.

“Although seawalls were recognized by the Territorial government as the primary cause of beach erosion, and were prohibited in 1917, the ban was not enforced. Approximately 37 seawalls were constructed in Waikīkī, and by 1920 most of the shoreline was lined with walls. By the 1930s only a remnant strip of beach remained along much of the shoreline. Large-scale beach nourishment projects were initiated, creating, or greatly expanding what would become Kaimana, Queen’s Surf, Kapiʿolani, and Kūhiō Beaches. These beaches were built to follow the straight lines of the existing seawalls and roads rather than the natural contours of the original bay and were held in place by a series of groins and breakwaters.”

— Conservation and Coastal Lands

It has been through practices that do not take into account the long-term impacts to the environment and ecosystem that has led to the issues that are being dealt with today.

At the core of Hawaiʻi tourism is the environment and its ecosystem. So, what will we do to ensure that the very thing driving tourism will be protected and preserved and allowed to prosper?