Perceptions of coastal change and adaptation: Beach use, values, and sea level rise at Pūpūkea–Paumalū, North Shore, Oahu, Hawaii

Abstract

Sea level rise (SLR) is accelerating due to ocean warming and melting ice, with global levels projected to rise, putting global coastal assets and livelihoods at risk. Hawaiʻi is projected to experience at least 1meter of vertical rise in mean sea level by the end of the century. Along the North Shore of Oʻahu, coastal communities such as Pūpūkea–Paumalū face increasing threats to infrastructure, beach access, and cultural relationships to place, posing significant challenges for shoreline management. The extent to which North Shore beach users - including residents, businesses, and community groups - understand SLR impacts and adaptation strategies remains unclear. These strategies include shoreline hardening, rebuilding or adapting in place, managed retreat, and ecosystem-based adaptation. This research examines how beach users understand coastal change, value the shoreline, and evaluate tradeoffs among these adaptation strategies. Data was collected through 85 intercept surveys with beach users between Sunset Point and Kapoʻo, conducted between Agusust 1st, 2025 and February 28th, 2026. In addition, 15 semi-structured interviews were conducted with selected survey respondents and additional recommended experts. Survey data was analyzed using descriptive statistics, while interview responses were analyzed using inductive thematic coding. Results show that beach users at Pūpūkea–Paumalū strongly value the beach for recreational and ecological reasons, broadly recognizing that sea-level rise will alter the shoreline. Willingness to support adaptation strategies varied with relationship to place: long-term non-beachfront residents and frequent users prioritized protecting access and cultural continuity, often expressing resistance to hard armoring, while beachfront homeowners were open to engineering solutions to protect their property, and visitors were more supportive of retreat-based or ecosystem-based approaches. Findings were shared with project team members of the North Shore Beach Management Plan (NSBMP) through this report, providing place-based insights into stakeholder values and adaptation tradeoffs. By grounding management recommendations in local knowledge and user priorities, this research supports the NSBMP’s goal of fostering community-supported, place-based adaptation pathways in the face of accelerating sea-level rise.