Photo Credit: B. Lingard
The Lagoon encounters risks of all kinds.
Why the Indian River Lagoon Is Naturally Vulnerable
The lagoon’s shape and limited ocean exchange make the Indian River Lagoon ecosystem slow to recover from pollution and environmental change.
Lagoons are fragile and vulnerable to changes in freshwater, nutrient and pollutant loads. Materials that enter the lagoon often stay there for long periods because of the lagoon’s limited connections to the ocean. This time can be as much as 1 year in northern lagoon portions far removed from an inlet.
Additionally, external factors have vastly changed the lagoon watershed in the past century:
- Human population growth
- Land-use changes
- Water diversions
- Coastal development
Channelization of land has increased by as much as 300% in some parts of the lagoon. Water coming from land travels to the lagoon much faster than it did before humans changed the landscape.
In short, natural limits mean things entering the lagoon last far longer than they do in open coastal waters.
Photo Credit: K. Hirst
Photo Credit: J. Crawford
Photo Credit: H. McVay
Multiple Stressors Are Affecting the Lagoon at Once
The lagoon’s decline results from overlapping pressures rather than a single source or event.
No one thing is ailing the lagoon. Many things harm it.
Some of the Indian River Lagoon’s problems have been 70 years in the making, while others are new. These are some of the primary stressors currently affecting the lagoon:
- Poor water quality (high temperatures, fluctuating salinity, low pH and low dissolved oxygen)
- Excess nutrients (nitrogen and phosphorus)
- Contaminants (bacteria, pathogens, chemicals, medications, etc.)
- Stormwater runoff
- Harmful algal blooms
- Land-use and coastal development practices
- Wetland alteration, fragmentation and loss
- Invasive exotic species
- Litter, debris, derelict boats and fishing gear
- Overexploitation
- Ocean acidification and rising sea levels
Because the lagoon is long and narrow, the problems occurring in one region are often not the same as those in other parts.
In the northern and central IRL regions, major stressors include wastewater and septic effluents, stormwater runoff, algal blooms, fish kills and muck. In the Southern IRL and St. Lucie River Estuary, the major stressor is high-volume freshwater discharges from Lake Okeechobee and the surrounding basin.
Because stressors vary by region, solutions must reflect local conditions across the lagoon system while supporting healthy communities.
Key Environmental Issues Harming the Lagoon Today
Each issue listed below contributes differently but collectively to declining water quality and habitat health. Understanding that issue helps clarify how it interacts within the larger Indian River Lagoon ecosystem.
Click an issue to learn more about it.
How Human Activity Shaped Today’s Lagoon Conditions
Centuries of land alteration and water control fundamentally changed how water moves through the Indian River Lagoon watershed.
The problems plaguing the IRL have persisted for centuries. One of the things we hear frequently is that it’s taken us 70 years to get to this place. Actually, it’s taken much longer than that.
The first significant human impacts on the lagoon occurred in 1768, when settlers established the short-lived Turnbull colony at New Smyrna. These early settlers constructed the region’s first drainage canals, remnants of which remain today. The practice of draining water from the land and directing it to the IRL has characterized regional development ever since.
Beginning in 1916, the Florida legislature authorized special taxing districts to encourage urban development, citrus agriculture and ranching. This resulted in the establishment of water control districts. These ditched, rerouted or permanently lowered nearly all natural streams and rivers to drain land once covered with water for 6 months or more yearly.
Today, virtually every neighborhood in the region is bounded by a series of canals that drain into one of the lagoon’s tributaries or directly into the IRL itself. Most of this effluent gets little to no treatment.
Modern lagoon conditions reflect long-term development decisions rather than recent changes alone.
The Melbourne-Tillman Water Control District, one of many water control districts in the region, services approximately 100 square miles of Palm Bay in Brevard County. Graphic: MTWCD
Photo Credit: State Archives of Florida
How Canals Changed Water Flow and Lagoon Health
Canals accelerate runoff, carrying pollutants and nutrients directly into the lagoon.
People have long dug canals throughout the Indian River Lagoon region to prevent flooding and quickly drain water from the land. When it rains, water that doesn’t soak into the ground runs off land into the nearest storm drain or canal. From there, it goes into the lagoon.
In undeveloped areas, stormwater runoff is relatively low in volume and generally low in nutrients and other pollutants. But roofs, roadways, driveways, sidewalks and other paved surfaces prevent rain from soaking into the ground in highly developed areas. In these areas, most rainfall becomes runoff.
Chemicals, pet waste, eroded soils, leaf litter, trash, vehicle fluids and other items are pollutants. These materials enter neighborhood ditches and canals and flow with the water directly to the lagoon. Excess nutrients (nitrogen and phosphorus) from those materials are then available to plants like seagrasses and algae, which use them for food.
In balanced ecosystems, plants take up and use nutrients that enter the system with little excess remaining. When excess nutrients are available in an ecosystem, algae can grow uncontrollably, creating a bloom. These blooms can result in depressed oxygen levels, fish kills and poor water quality.
Faster drainage leaves less opportunity for natural filtration before water reaches the lagoon.
Bring the Lagoon Back to Health: A Call to Action
Restoring health to the Indian River Lagoon requires every level of government, every agency, every county, every city and every citizen. No single effort can sustain it without shared responsibility and commitment.
Learn more about what we do to protect the IRL, or donate to One Lagoon through the IRLNEP to be part of the solution.