Indian River Lagoon — Facts and Figures

• The IRL is an “Estuary of National Significance,” one of 28 in the nation. The primary goal of the Indian River Lagoon National Estuary Program (IRLNEP) is to protect this ecologically significant estuary that is threatened by degradation caused by human activity. IRLNEP coordinates watershed management at the local level, building community-based processes to implement protection programs with specific actions to address environmental problems.
• The IRL is also designated as an aquatic preserve, an Outstanding Florida Waterway, and a Surface Water Improvement and Management (SWIM) Program Water Body.

• The Indian River Lagoon (IRL) is a 156-mile long estuary located on Florida’s East Coast. The lagoon is long and narrow, occurring between approximately 27 and 29 North latitude.
• The IRL system is comprised of three distinct water bodies, Mosquito Lagoon, Banana River, and the Indian River.
• The IRL is an estuary, not a river. Unlike true rivers, water flow in the IRL is not driven by gravity. Rather, it is the wind that primarily drives the circulation patterns within the lagoon.
• Six coastal Florida counties occur within the natural IRL watershed (Volusia, Brevard, Indian River, St. Lucie, Marin, and northern Palm Beach County).
• Like all estuaries, the IRL is a semi-confined water body characterized by mixing of saline oceanic water and freshwater from upland sources. Water is exchanged between the IRL and the Atlantic through five ocean inlets—cuts in the barrier island chain. Although natural in origin, the inlets have been artificially stabilized and are maintained through human manipulation.
• The salinity, tidal influence, and degree of flushing characteristic of a particular portion of the lagoon depend in large part on its proximity to an inlet and to freshwater inputs from streams, rivers, ditches, and canals.

• The IRL has been cited as among the most biologically diverse estuaries in North America.
• The IRL straddles a warm-temperate climate to the north and a subtropical climate to the south. The influence of these two distinct biogeographical provinces is one of the factors underlying the spectacular biodiversity found within the Lagoon.
• High biodiversity is also fostered by the presence of a number of distinct habitats that serve as home to the plants and animals of the IRL. Seagrass meadows, mangrove forests, and saltmarshes are foremost among IRL habitats whose continued health is essential for a healthy lagoon.
• The IRL watershed is home to more than 2,100 different species of plants and more than 2,200 animal species, including some 700 fish species and 310 bird species.
• Approximately 50 threatened or endangered species can be found in the IRL region, including 12 plants and 36 animals.