By Julie Christian, Environmental Scientist 

Seagrass coverage is an important indicator for the overall health of the Tampa Bay estuary, and long-term monitoring allows scientists to track changes over time. Seagrasses are an important habitat in Tampa Bay that not only provide shelter and food for a variety of fish and invertebrate species, but also help stabilize sediments, which aids in improving water quality. 

Tampa Bay lost seagrass acreage in the 1970s and 1980s due to poor water quality. Subsequent improvements in wastewater treatment in the region resulted in seagrass acreage rebounding to 1950s levels despite increasing population and development. Coverage estimates as recently as 2018 were more than 40,000 acres of seagrass. According to data provided by the Southwest Florida Water Management District (SWFWMD), as of 2024, seagrass coverage in the Bay has decreased to 31,563 acres. The majority of those losses occurred in Old Tampa Bay, which is now at a historic low for seagrass coverage. The reasons for the recent losses are unclear but are being investigated by the Tampa Bay Estuary Program (TBEP), SWFWMD, and other regional partners.

EPC Water Division staff partner with the TBEP and other agencies to monitor 61 long-term seagrass transects throughout Tampa Bay. EPC monitors 10 transects within Old Tampa Bay, Middle Tampa Bay, and off Egmont Key. The transect monitoring occurs annually during the seagrass growing season between July and October. EPC staff recently completed the 2025 seagrass monitoring event.

Learn more about EPC's seagrass monitoring program