This same coastal erosion also endangers the Paia Mantokuji Soto Mission, a temple built in 1906 to serve Japanese immigrant laborers. The temple, along with its associated buildings, is precariously close to the ocean, with fabric-covered sand-filled cages, known as geotechnical containers or revetments, being the only defense against the encroaching sea.

This situation at Mantokuji Bay is part of a larger problem affecting the Hawaiian Islands, where climate change-driven sea level rise and coastal erosion are threatening shoreline buildings and beaches. On Maui, where beaches are eroding faster than on other Hawaiian islands, the problem is particularly acute.

The temple's board of directors hired engineering firm Oceanit in 2018 to find a solution, but the process has been complicated. Options under consideration include ongoing erosion mitigation, coastal ecosystem restoration, or moving the temple and graveyard inland — a strategy known as managed retreat.

While no final decisions have been made, Oceanit's senior engineer, Michael Foley, believes that whatever strategy is ultimately chosen could serve as a model for other parts of Hawaii.

The state is already grappling with the loss of at least 13 miles of beach due to sea level rise, with 70% of its beaches threatened. A study by the University of Hawaii found that 40% of Oahu's beaches could be gone by mid-century, leading researchers to urge against further shoreline hardening.

The community at Mantokuji Soto Mission remains hopeful despite the uncertainty. In mid-July, scores of people gathered at the temple for the annual O-Bon Dance Festival, a time to honor ancestors and assure them that all is well. Before the festival, Oceanit staff gave a public presentation at the Paia Community Center, explaining the stakes if nothing is done to address the erosion at Mantokuji Bay.

Foley emphasized that the shoreline is moving inland at an average rate of 1.6 feet per year, a pace that is accelerating.

The possibility of moving the temple and graveyard inland has been largely ruled out due to the structural weakness of the buildings and the impracticality of relocating hundreds of gravesites. Instead, the temple's board of directors, led by Eric Moto, is exploring the viability of beach ecosystem restoration as a nature-based approach.

This effort involves extensive community outreach, fundraising, and grant-writing, as the project is expected to cost tens of millions of dollars.

Despite the challenges, the temple community remains committed to finding a solution. While some experts argue that beach nourishment is a costly and unsustainable approach, the temple sees it as a way to buy time and preserve their cultural and spiritual heritage.

As the situation unfolds, Mantokuji Soto Mission continues to serve as a reminder of the impact of climate change on vulnerable coastal communities and the difficult choices they face in adapting to an uncertain future.