Abstract

Due to both natural and anthropogenic disturbances, coral reefs worldwide have undergone drastic degradation. The Florida Keys Reef Tract (FKRT) has suffered exceptionally steep declines in coral cover, biodiversity, and ecosystem function. To abate this decline and restore ecosystem structure to these invaluable habitats, practitioners are increasingly implementing coral restoration strategies. The functional roles of reef fishes in mediating coral reef restoration success have received limited attention, yet interactions such as herbivory and nutrient deposition are integral to reef health. In particular, herbivorous groups such as parrotfishes provide reefs with an influx of key nutrients and top-down control on harmful algae. The ability to predict the spatial distribution of these interactions could aid in the development of ecosystem-based restoration strategies. Using reef and mangrove visual census data for fishes, and environmental predictors including bathymetry, habitat type, and indices of water quality, we construct habitat suitability models (HSMs) for species within a functional group of herbivores that undergo ontogenetic habitat shifts across the FKRT: blue (Scarus coeruleus), midnight (Scarus coelestinus), and rainbow parrotfish (Scarus guacamaia). We illustrate how the resulting HSMs can be used to derive cost surfaces, across which least-cost paths are determined using connectivity modeling, leading to ecologically realistic predictions of the species’ distributions and movements throughout this heterogenous seascape. Finally, we highlight how metrics of connectivity generated from this modeling framework can be used to identify candidate reefs for coral restoration that are most likely to benefit from ecological interactions with these herbivorous, multi-habitat reef fishes.