Habitat-shifting predatory and herbivorous reef fishes exhibit spatial partitioning despite shared biophysical drivers of seascape use.

Abstract

Context: Climate change and anthropogenic stressors are degrading coastal biogenic habitats, disrupting the vital pathways fish use to shift from nearshore nurseries to offshore reef environments. Although fishes are critical for ecosystem health, spatial management rarely accounts for the interconnectedness of fish habitat needs across their life cycle.

Objectives: To examine and compare drivers of habitat use for subadult size classes of five habitat-shifting fishes from two feeding guilds: mesopredators and herbivores. To assess the multi-species suitability of existing management zones.

Methods: We used MaxEnt to model habitat suitability for our focal fishes across the Florida Keys, USA, and performed permutation analyses to compare habitat use patterns and drivers among species. We used predicted suitability maps to quantify suitability for 58 management zones.

Results: Benthic habitat type was the strongest driver, with patch- and aggregate-reefs emerging as the most suitable across species. Habitats were more moderately suitable for mesopredators across the nearshore-offshore gradient, while S. guacamaia stood out among the herbivores as preferring nearshore and mid-channel habitats over offshore habitats. We observed spatial partitioning, even among species with similar diets and preferred habitat types. All management zones were more suitable than the region-wide average, with restoration zones exhibiting higher predicted suitability than protection zones. Considering their high suitability for these species, patch reefs are underrepresented in current management practices.

Conclusions: Our findings highlight the need to preserve connected habitat corridors that span nearshore-offshore gradients, and we encourage practitioners to incorporate habitat suitability into site selection. To maximize ecosystem benefits, future work should consider the habitat and connectivity needs of a broader range of species and functional groups.

Supplementary information: The online version contains supplementary material available at https://doi.org/10.1007/s10980-026-02456-2.