Florida's Estuaries: Polluted Paradise?

Florida's estuaries are in crisis. Estuaries are highly productive ecosystems that support a wide variety of plants, fish, birds, and other animals. They are also economically valuable to Florida, supporting commercial and recreational fishing, tourism, and other industries. However, Florida's estuaries face significant threats from pollution, invasive species, and the impacts of climate change, including sea-level rise, flooding, and erosion. Human activities such as land development, structural changes, and the discharge of polluted water from agricultural and urban areas have led to the degradation of these fragile ecosystems, with consequences for both human health and the environment. This has resulted in the loss of vital estuarine habitats and the decline of dependent species, impacting the health of the state's estuaries.

Phosphorus pollution from agricultural land

Florida's estuaries are in crisis. The state's estuaries are among its most environmentally, economically, and culturally important waters, supporting commercial and recreational fisheries, recreation, and tourism. However, they are also some of the most threatened natural habitats in Florida, largely due to human activity.

One of the key issues affecting Florida's estuaries is phosphorus pollution from agricultural land. According to the Florida Oceanographic Society, more than 75% of the phosphorus entering Lake Okeechobee comes from agricultural land uses. This has had a devastating impact on the lake's water quality, which is at an all-time crisis level. The lake's polluted water is then discharged into the St. Lucie and Caloosahatchee estuaries, causing significant public health, economic, and environmental harm. The pollution includes excessive phosphorus, nitrogen, suspended sediment, and, at times, toxic blue-green algae. The health of people and their pets in the estuarine communities has been adversely impacted by these discharges, with the St. Lucie region experiencing twice the national average rate of death due to non-alcoholic liver disease, linked to the lake discharges.

For over 90 years, state and federal agencies have diverted polluted water from Lake Okeechobee to provide flood protection and irrigation benefits to agricultural and urban communities south of the lake. This has resulted in the environmental and economic health of the region being sacrificed. While efforts have been made to reduce pollution, including research, water quality monitoring, and regulatory programs, the state continues to allow landowners to discharge high levels of nutrients with little to no enforcement.

Agricultural activities, such as the use of pesticides and fertilizers, contribute to phosphorus pollution in Florida's estuaries. The construction of major agricultural canals has also played a role, as these canals now contribute significant loadings of nutrients and unknown quantities of pesticides to the water bodies. The dominant land use in the watershed of the SLRE estuary, for example, is agriculture, accounting for 55% of the land use. This has had a detrimental impact on the estuary, turning its once clear waters and sandy bottom into dark and turbid waters overlying an oozy muck layer.

To protect and restore Florida's estuaries, it is crucial to address the issue of phosphorus pollution from agricultural land. This may involve implementing stricter regulations and enforcement, assisting agricultural landowners with best management practices, and reducing the use of pesticides and fertilizers. By taking these steps, Florida can help ensure the long-term health and sustainability of its estuarine environments and the communities that rely on them.

Invasive species

Florida's estuaries are in crisis. For over 90 years, state and federal agencies have sacrificed the region's environmental and economic health by diverting polluted water from Lake Okeechobee to provide flood protection and irrigation to farms and communities south of the lake. The St. Lucie and Caloosahatchee estuaries have suffered significant public health, economic, and environmental harm due to these polluting discharges.

The pollution of Florida's estuaries has facilitated the growth of invasive species. Invasive species are plants and animals that don't grow naturally in an area. They can be accidentally or intentionally introduced to estuaries through transportation or human introduction. Invasive species compete with and prey upon native species, reducing their populations and removing critical services from the fragile ecosystem. For example, the oyster population of the Chesapeake Bay was nearly wiped out due to overharvesting. As oysters serve as water filters, many other organisms were put at risk as harmful pollutants remained in the water.

Florida's estuaries are particularly vulnerable to invasive species due to their subtropical climate and connectivity to the greater Everglades ecosystem. The increasing human population in Florida has also led to land development and structural changes that have threatened the natural habitats of the state's estuaries. Sea-level rise, flooding, and erosion caused by climate change are also impacting an increasing number of areas with increasing frequency.

The combination of nutrient runoff and increased temperatures due to climate change can decrease dissolved oxygen levels below a threshold, threatening benthic communities. Warmer temperatures also favour harmful algal blooms, which can suffocate fish and plant life by using up valuable oxygen from the water.

To address the threat of invasive species, Florida must implement best management practices to reduce land-based pollutant and nutrient loads impacting species and habitats. Developing invasive species control plans that address the synergistic effects of climate change is also crucial.

Climate change

Florida's estuaries are in crisis. The state's economically important estuaries are suffering from pollution and the impacts of climate change. Climate change-induced sea-level rise, flooding, erosion, and altered river flow are among the primary threats to Florida's estuaries. These changes can lead to increased salinity, which can harm plants and animals, alter habitats, and reduce the estuaries' ability to provide essential services such as seafood production and shoreline protection.

The state's estuaries, such as the St. Lucie and Caloosahatchee estuaries, are vital to Florida's economy, supporting commercial and recreational fisheries, tourism, and flood protection for agricultural and urban communities. However, these estuaries are facing significant environmental and public health challenges due to polluted water being diverted from Lake Okeechobee. The lake's water contains excessive phosphorus, nitrogen, suspended sediment, and, at times, toxic blue-green algae. The sediment turns the once-clear waters dark and turbid, smothering oyster and seagrass beds.

Florida's estuaries are also threatened by invasive species, overharvesting, and oil and gas drilling. The BP oil spill in 2010 had catastrophic effects on the Gulf Coast's salt marshes and wildlife. Additionally, the increasing human population in Florida has led to land development and structural changes that impact the estuaries.

The loss of estuary habitat due to sea-level rise and human manipulation of waterways is a significant concern. This loss threatens to displace and disenfranchise communities, especially marginalized and communities of color. Entire cities in Florida, such as Miami, are expected to be underwater by the end of the century without significant mitigation and adaptation efforts.

To address these challenges, Florida's water management districts have implemented protocols and plans to minimize the wasteful use of fresh water. Additionally, organizations like Restore America's Estuaries work with partners nationwide to engage local communities, advance science and policy, and ensure the benefits of coastal restoration are shared by all.

Human population growth

Florida's estuaries are in crisis due to pollution and human population growth. The state's population growth was the highest in the country between 2022 and 2023, with four of the five fastest-growing metropolitan areas in the US located in Florida. This growth has had a significant impact on the state's estuaries, which are among the most threatened natural habitats in Florida.

The increasing human population has led to more land development and structural changes, such as the sale of citrus groves and agricultural land for housing developments. This has resulted in the loss of natural habitats and increased pollution. For example, the diversion of polluted water from Lake Okeechobee has been done to provide flood protection and irrigation benefits to agricultural communities south of the lake. However, this has come at the cost of the environmental and economic health of the region. The lake discharges contain excessive phosphorus, nitrogen, suspended sediment, and sometimes toxic blue-green algae, which have caused significant public health, economic, and environmental harm.

The Florida Oceanographic Society has reported that more than 28 million pounds of sediment enter the river annually, with over 80% coming from Lake Okeechobee discharges. This has turned the once-clear waters and sandy bottoms of estuaries into dark and turbid waters, smothering oyster beds and seagrass beds. The high levels of nutrients in the water have also fueled harmful algal blooms, which have had devastating effects on marine life.

Additionally, the increasing human population has put pressure on coastal areas, with eight of the ten largest US cities situated in estuary regions. The threat of sea-level rise, flooding, and erosion due to climate change is impacting these areas more frequently. Without drastic mitigation and adaptation efforts, cities like Miami, Florida, are expected to be underwater by the end of the century.

While human population growth has had negative impacts on Florida's estuaries, efforts are being made to counter these effects. Organizations like Restore America's Estuaries work with partners nationwide to engage local communities, advance science and policy, and ensure the benefits of coastal restoration are shared by all communities.

Sewage and septic systems

Florida's estuaries are in crisis. The state's environmental and economic health has been sacrificed by state and federal agencies through the diversion of polluted water from Lake Okeechobee to provide flood protection and irrigation benefits to farms and communities south of the lake. The St. Lucie and Caloosahatchee estuaries have been particularly affected, with the health of people and their pets in these estuarine communities adversely impacted by toxic blue-green algae.

Florida's rapid population growth has led to higher densities of septic tanks than the soil and groundwater can assimilate. Conventional septic tanks are not designed to remove nutrients, and their effluent is released into underground drain fields, where soil filters the water back into the groundwater. When this occurs near local surface waters and shallow aquifers, the excess nutrients in the effluent make their way into the water and cause algal blooms that grow out of control. The algae release toxins that can make water unsafe for plants, wildlife, and humans—a condition known as eutrophication.

Florida has more than 2.6 million on-site septic tanks in use, serving about 30% of the state's population. The issue of nutrient pollution has been known for decades, but the transition from septic tanks to municipal sewers or other treatment methods has been slow due to the expense involved for communities and homeowners. To address this issue, Lake County has implemented Distributed Wastewater Treatment systems, a cost-effective solution that reduces nutrient pollution and preserves Florida's natural waters.

The Florida Department of Environmental Protection (FDEP) plays a crucial role in regulating onsite sewage treatment and disposal systems (OSTDS) or septic systems. As of July 1, 2021, the FDEP has been responsible for enforcing Florida's laws and rules regarding OSTDS. Starting in 2025, the FDEP will also manage septic system permitting in 16 counties, while the local county health departments will continue to handle permitting and inspections in the remaining counties. Operating permits are required for various types of septic systems, including aerobic treatment units (ATUs) and commercial septic systems.

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