Coral community dynamics across anthropogenic and natural stressors in Portobelo National Park, Colon, Panama

Understanding how coral communities respond to overlapping local stressors is essential for identifying potentially resilient reef sites within marine protected areas. In Portobelo National Park, Caribbean Panama, coral assemblages occur under combinations of human and natural pressures. Using field-based stressor proxies (tourism, boat traffic, port activity, coastal settlements, river input, wave exposure, and elevated algal cover), we characterized stressor regimes across 16 sites and quantified coral community composition using genus-level surveys conducted during 2021–2022 to assess spatial variation across stress regimes. A PCA based on these proxies revealed different combinations of co-occurring anthropogenic pressures and environmental conditions, with the first two axes explaining 60.9% of the variation. K-means clustering in PCA space identified three stressor regimes: towns/boat traffic/port activity, tourism/wave exposure, and river input/wave exposure/algal cover, and an NMDS based on genus-level data showed that coral communities varied across these regimes, although groups overlapped substantially. PERMANOVA revealed significant differences in coral community composition among regimes (R² = 0.229, F = 1.93, p = 0.039), while PERMDISP indicated no significant differences in multivariate dispersion (p = 0.182). Genus richness, Shannon and Simpson diversity, and dominance did not differ significantly among regimes. Agaricia sp. was the dominant genus across the surveyed sites, accounting for approximately 48.6% of total genus-level coral cover. Unexpected patterns emerged, including diverse coral assemblages at sites experiencing multiple overlapping pressures. Our results provide one of the first spatially explicit assessments of local stressor regimes and their associations with coral community structure in Portobelo National Park. Several sites maintain diverse coral assemblages despite persistent human pressure, highlighting the importance of considering local environmental conditions alongside anthropogenic stressors. These spatial patterns offer a baseline for evaluating potential resilience and guiding future monitoring and management efforts in the park.