Learn More: Seagrass

What does this mean?

Seagrass beds are important to estuarine productivity, providing a protective nursery area for juvenile fish, shrimp, crabs, and other invertebrates, and providing a substrate for growth of algal ephiphytes which serve as food for fish and crustaceans. Manatees feed directly on seagrasses. Seagrass roots also bind soils and reduce erosion and turbidity during strong tidal currents or storms, and by absorbing storm energy, they protect coastal habitats, property and human habitation.

Seagrass maps are found on the bay pages of coastal Water Atlas websites, and also can be viewed using the Advanced Mapping application.

How are the data collected? (Methods)

Seagrass is assessed in two different ways, through aerial surveying from aircraft, and by in-water data collection by environmental scientists working for state and local agencies.

For decades Florida's Water Management Districts have flown biannual aerial surveys, photographing seagrass beds. The flights typically are performed in winter when water clarity is at its maximum. Photo-interpretation is then used to identify seagrass beds from 1:24,000 and 1:10,000 scale natural color aerial photography. The final results are processed in a geographic information system (GIS) that allows for the location of seagrass beds to be displayed in digital maps, such as those found in the Water Atlas Mapping Application. Until recently the photo-interpretation was entirely manual by subject matter experts, but computer software is now being used to help facilitate the seagrass bed delineation and characterization process, making it quicker and less labor-intensive. This video from the Southwest Florida Water Management District discusses the change in method.

The Florida Fish & Wildlife Conservation Commission's (FWC) Seagrass Integrated Mapping and Monitoring (SIMM) program was developed to protect and manage seagrass resources in Florida by providing a collaborative platform for reporting seagrass mapping, monitoring, and data sharing. Elements of the SIMM program include:

  1. Ensuring that all seagrasses in Florida waters are mapped at least every six years,
  2. Monitoring seagrasses throughout Florida annually,
  3. Updating and publishing online regional chapters continually as new information becomes available, and
  4. Publishing a comprehensive report every two years that combines site-intensive monitoring data and trends with statewide estimates of seagrass cover and maps showing seagrass gains and losses.

Source: Yarbro, L. A., and P. R. Carlson Jr. 2016. Executive Summary. pp. 1-28, in L. A. Yarbro and P. R. Carlson Jr., eds. Seagrass Integrated Mapping and Monitoring Report No. 2. Fish and Wildlife Research Institute Technical Report TR-17, version 2. Florida Fish and Wildlife Conservation Commission, St. Petersburg. 281 p. DOI: 10.13140/ RG.2.2.12366.05445.

In-water monitoring is performed by biologists working for FWC, as well for the Florida Department of Environmental Protection Districts and Aquatic Preserves, county governments and National Estuary Programs. The survey data collected is combined by FWC into a comprehensive statewide report with sections for each region of the state. Parameters monitored include percent coverage, species composition, presence/extent of epihytic algae, water quality and clarity, and water/seagrass bed depth.


Seagrass locations were analyzed using a geographic information system (GIS) in order to calculate the total acreage of patchy or continuous seagrass beds within the coastal waterbodies.

Caveats and Limitations

Although aerial photography is collected under cloud-free conditions, turbidity in some areas may reduce the accuracy of seagrass bed delineation, particularly around passes.

Additional Information