A multi-decadal assessment of social thresholds and outcomes in marine social-ecological systems in Hawaiʻi

Coastal communities and nearshore ecosystems comprise social-ecological systems (SESs) where ecological goods and services (EGS) help meet many social, economic, and cultural objectives. In an era of political and environmental change, acute and chronic stressors can induce regime shifts, transitioning systems from high-functioning states to less favorable ones with diminished EGS provisioning. Despite the inherent interdependence of human communities and resource ecosystems, and management’s ultimate goal to promote human well-being, social regime shifts within SESs are underexplored relative to ecological regime shifts. This case study uses social indicators to identify temporal trends and thresholds across fisheries, tourism, and coastal employment in the Hawaiian SES. Generalized Additive Models (GAM) identify periods of change and link them to regulatory and environmental drivers. Composite indices score social outcomes over time and across local communities using Data Envelopment Analysis (DEA). Trends and thresholds coincided with regulatory changes, economic conditions, and environmental perturbations. Together, threshold identification and outcome ranking assess social adaptability to resource changes and provide insight for adaptive management of regime shifts for marine ecosystems in Hawaiʻi.