Project Maps Location and Coral Cover of Florida Keys’ Patch Reefs

To learn more about their status, researchers are mapping patch reefs in the Upper, Middle and Lower Florida Keys to determine their coral cover.

Patch reefAround the world, a vital habitat for marine life is in peril. Coral reefs are declining in health and dwindling in size, clouding the future for the countless species that rely on reef habitat. Large-scale die-offs of coral species can occur after bleaching, typically a consequence of above-normal water temperatures. Poor water quality, algae overgrowth, and disease also threaten one of the most diverse and highly productive ecosystems on the planet.

The Florida Keys represent the southern extent of the Florida Reef Tract, which is the largest coral structure in North America and faces an uncertain future. Prevalent in the Keys are patch reefs—small, often circular formations separate from larger reef structures. To paint a better picture of the current state of those reefs, FWRI Center for Spatial Analysis researchers began a project to map patch reefs in the Upper, Middle, and Lower Florida Keys and determine their coral cover.

The researchers used satellite data to map the number, location, and size of patch reefs in the region. Project scientists then performed field checks at random locations to verify the satellite data and record the percentage of coral cover for each reef. They further divided the Upper, Middle, and Lower Keys into zones based on depth and distance from shore. Within those zones, scuba divers measured coral cover at randomly selected sites. Throughout the Florida Keys, researchers have found significantly higher numbers of patch reefs than they expected: 1,242 in the Upper Keys (not including Biscayne Bay National Park), 351 in the Middle Keys, and 1,975 in the Lower Keys. Average live coral cover is 18.5 percent but varies greatly by location.

To allow open access to their field and satellite information, as well as data from other sources, project scientists are creating a Web site to display the geospatial data. Once the project is complete, it will provide the most comprehensive map available of Florida Keys patch reef habitat. Making this collection of data openly accessible assures its value to coral reef researchers and resource managers.

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