Persisting, emerging and contracting: The dynamic nature of non‐native hotspots and their implications for management

Non‐native species threaten coral reefs by altering ecosystem structure and resilience, particularly on isolated tropical islands experiencing strong local and global stressors. In Hawaiʻi, native reef communities face cumulative impacts from the incursions of multiple non‐native fishes.

We combined species distribution models and hotspot analyses to identify potential high‐risk areas where environmental conditions favour co‐occurrences of non‐native species under present and future scenarios.

While predicted non‐native richness was similar across islands, sub‐island patterns were highly heterogeneous, with areas near ports and developed shorelines consistently exhibiting elevated co‐occurrence risk. Baseline hotspot analyses indicated that Oʻahu and Hawaiʻi Island host the majority of high‐risk areas, followed by Kauaʻi and Molokaʻi.

Crucially, we identified three hotspot trajectories across time and emission scenarios: persisting hotspots remaining high‐risk (e.g. Pearl Harbour on Oʻahu; western Molokaʻi), emerging hotspots developing by mid‐ to late‐century (e.g. Poʻipū on Kauaʻi) and contracting hotspots disappearing under future ocean conditions (e.g. Kailua‐Kona on Hawaiʻi Island).

These patterns demand differentiated management strategies: (i) early detection and rapid response (also including biosecurity measures) in emerging hotspots, (ii) a combined approach that encompasses removal, monitoring and targeted outreach when non‐native threats remain and (iii) habitat restoration or rehabilitation where invasion risk contracts.

Synthesis and applications . By linking explicit hotspot projections to distinct management phases, this study provides a proactive framework for non‐native species control, transitioning from reactive eradication efforts to future‐oriented planning that optimizes managers' often limited resources. This predictive framework is readily adaptable to other tropical island ecosystems facing similar biological and environmental pressures.