Indian River Lagoon
Species Inventory

Shoreline Development

Land use changes from the growing population and urbanization in Florida and throughout the world have altered coastal ecosystems. Along the Indian River Lagoon, many habitats have been altered or removed to accommodate booming population growth.

Photo credit: K. Roark, Flickr

Among the greatest impacts of this development are habitat loss and changes in water quality from runoff and other pollutants.

Habitat Impacts

Since the 1950s, an estimated 75 percent of the Indian River Lagoon’s mangroves and salt marshes have been destroyed, altered or functionally isolated. These marginal habitats have been removed and filled with dredged material to create roads, residential communities and businesses. Changes in mangrove and salt marsh areas have direct repercussions for bordering sand and mudflats.

The habitat fragmentation that results from this rapid development has fractured animal communities and left ecosystems more vulnerable to other habitat disturbances.

Preserved natural areas and various state permitting processes aim to minimize such habitat loss. Substantial mangroves and salt marshes lay within protected areas such as the Merritt Island National Wildlife Refuge and property managed by the Florida Department of Environmental Protection. Proper management provides conservation from further development and encourages restoration programs that work to increase habitat acreage.

Freshwater released from Lake Okeechobee creates a distinct boundary as it meets salty ocean water at the St. Lucie River inlet. Credit: E. Lippisch

Water Impacts

Development of the built human environment has greatly increased the amount of freshwater that drains to the Indian River Lagoon. This change in the natural volume and timing of freshwater inputs to the lagoon has greatly altered the health of the lagoon.

One major influence is the complex network of agricultural and drainage canals constructed over the 20th century, which deliver up to 2.5 times the amount of freshwater than the estuary system can naturally handle. These freshwater surges not only impact the salinity of the brackish estuary, but also allow more direct flow of sediments and other pollutants into the lagoon.

A drainage canal in south Florida. Credit: J. Thurlow-Lippisch

Unlike pollution coming from a factory or water treatment facility, non-point source pollution cannot be traced back to a single point of origin. It includes the diluted discharges of contaminant-laden water from residential and agricultural sources, nutrient inputs from septic drainage fields, and pollutants carried to the lagoon as stormwater runoff.

Urbanization and the accompanying increase in paved, impermeable surfaces reduces the watershed’s ability to filter rainfall and other water runoff. In undeveloped, natural areas, rainfall percolates down into porous soil, which mechanically and biologically filters out contaminants before they can reach the lagoon. As more and more land is paved over, this important natural process is lost.

Increased sediments and pollutants from human activity also drives the formation of muck on the lagoon bottom.

Jupiter Inlet from above. Many of the lagoon’s water-adjacent areas are heavily developed, though the region has many parks and natural preserve areas. Credit: P. Owen