Mapping the Hidden Mosaic: How High-Resolution Satellites Help Us Understand Seagrass and Reef Dynamics in the Florida Keys

 When most people think of the Florida Keys, they picture clear blue water, white sand, and vibrant coral reefs. But beneath the surface lies a far more intricate and dynamic landscape built from the shifting balance among coral reefs, seagrass meadows, sand flats, and hard-bottom communities. Together, these habitats form a mosaic that sustains the rich biodiversity of the Keys—from sea turtles and manatees to the small forage fish that fuel coastal food webs.

In the Seascape Ecology Lab, we investigate how this mosaic is arranged across the seafloor and how its spatial structure influences ecological processes. A central objective is to produce science that supports ecosystem-based management in the region. This includes contributing scientific guidance to the Florida Keys National Marine Sanctuary, where updated spatial data are crucial to inform decisions about expanding marine protected areas, particularly in seagrass-rich areas that play key roles in coastal resilience and connectivity.

Our project maps and quantifies this benthic “patchwork” across the Upper, Middle, and Lower Keys, regions that differ in tidal energy, disturbance history, water clarity, and the degree of Everglades influence. Despite their ecological importance, these seascapes have historically lacked fine-scale mapping that captures seagrass-patch reef arrangement patterns and their temporal dynamics. To address this, we applied remote sensing techniques by integrating satellite imagery with field surveys to classify seagrass, coral reef structures, and hardbottom habitats using a machine-learning Random Forest model tailored to each region.

Once mapped, we measured spatial pattern metrics to quantify the arrangement, fragmentation, contiguity, and connectivity of seagrass relative to adjacent reef features, and revealed crucial regional contrasts. In the Upper Keys, seagrass and reef habitats form a highly contiguous landscape that likely enhances nursery function and supports greater cross-habitat fish movement. In contrast, the Middle Keys exhibit lower habitat contiguity, where reef patches are often isolated from seagrass beds, with reduced ecological connectivity and resilience. The Lower Keys display both high contiguity and pronounced spatial heterogeneity, producing a complex and well-connected mosaic that appears especially well suited for effective conservation measures.

These results matter for the Florida Coastal Everglades (FCE) LTER because the Florida Keys sit downstream of the Everglades and are shaped by the same freshwater, climate, and disturbance processes that FCE monitors across the coastal gradient. The habitat metrics developed through this project provide a valuable baseline for detecting long-term change, linking benthic structure to ecosystem function, and identifying areas that may be particularly vulnerable or resilient to future environmental pressures.

This work demonstrates how the integration of remote sensing, seascape ecology, and spatial analysis can reveal the hidden architecture of South Florida’s coastal ecosystems. As restoration planning evolves, spatial tools like benthic maps will be essential for guiding adaptive management and ensuring that the ecological integrity of Florida's delicate ecosystems endures for generations to come.