For over a decade, the Indian River Lagoon, one of nation’s most biodiverse estuaries, has been teetering on the brink of disaster. Nutrient pollution led to chronic algal blooms that devastated the lagoon’s seagrass beds and marine habitat. By 2021, this ecological crisis reached a tragic peak, as the lagoon experienced one of its worst years on record for manatee deaths.
However, recent developments offer a glimmer of hope. Seagrass, which had been nearly wiped out in some areas, is beginning to grow back. Data collected in the summer of 2023 by The St. Johns River Water Management District showed some increase in seagrass extent compared to 2021, particularly in the northern Indian River Lagoon and southern Mosquito Lagoon. Furthermore, in-water surveys conducted in early 2024 documented natural seagrass growth in the Banana River Lagoon and northern Indian River Lagoon, indicating that restoration efforts are finally starting to take root.
A Decade of Decline
The trouble began in earnest more than ten years ago, largely driven by unchecked pollution. Nutrients from urban development, faulty septic systems, and agricultural runoff combined to create a perfect storm for unmitigated damage. Discharges from Lake Okeechobee, particularly during periods of heavy rain, flooded the lagoon with excess nutrients, sparking massive algal blooms. These blooms blocked sunlight from reaching the seagrass and led to widespread die-offs. Between 2013 and 2022, the Indian River Lagoon experienced a significant loss of seagrass, primarily due to pollution-driven algal blooms. During this period, more than 58% of the lagoon’s seagrass coverage was lost. And it kept getting worse.
Without healthy seagrass, the entire lagoon ecosystem began to unravel. Fish populations declined, water quality worsened, and manatees, a keystone species in the lagoon, faced starvation due to the loss of their primary food source. In 2021, Florida recorded the deadliest year on record for manatees. More than 1,000 died as a direct result of the seagrass collapse in the lagoon by the end of 2021. In 2022 the deaths due to starvation lingered with an estimated 400 more, prompting wildlife agencies to take the unprecedented step of providing supplemental lettuce in several areas.
Seeds of Hope
Despite the grim outlook, efforts to restore the Indian River Lagoon might be starting to pay off. According to data collected in 2023, seagrass coverage in the lagoon has increased compared to 2021 levels, with particularly encouraging growth in the northern Indian River Lagoon and southern Mosquito Lagoon. These areas, once devastated by nutrient pollution and algal blooms, are now seeing new seagrass beds take root.
Even more promising, in-water surveys conducted in January and February of 2024 have documented natural seagrass recruitment in the Banana River Lagoon and northern parts of the Indian River Lagoon. This natural regrowth signals that conditions in the lagoon are improving enough to support the return of this critical plant species without solely relying on human intervention.
Restoration Efforts Driving the Recovery
The return of seagrass to the Indian River Lagoon is a direct result of ongoing restoration efforts that have aimed to tackle the root causes of the lagoon’s decline. These efforts include:
Seagrass Planting Projects: To help restore the lagoon’s underwater meadows, conservation groups and scientists have been planting seagrass in key areas. These projects aim to rebuild the ecosystem from the ground up, creating new habitats for fish and other marine species while also improving water quality.
Living Shorelines and Buffered Shorelines: In an effort to reduce erosion and sediment runoff, many communities have been installing living shorelines, natural structures made of plants, sand, and rocks instead of metal and concrete. These shorelines help stabilize the lagoon’s banks, filter pollutants, and create habitat for marine life without causing further destruction.
Fertilizer Bans and Restrictions: Excessive use of fertilizers is one of the main contributors to nutrient pollution in the lagoon. Most Treasure Coast municipalities have enacted strict fertilizer bans and restrictions, particularly during the rainy season when runoff is at its highest. These policies help to reduce the flow of harmful nutrients into the lagoon.
Septic-to-Sewer Conversions: In many areas, particularly on the barrier island and northern areas of the estuary, outdated septic systems have been a major source of nutrient pollution. But with ever-burgeoning grant programs, Treasure Coast cities and counties are able to work more closely with homeowners and businesses to convert their properties from septic to sewer systems, significantly reducing the amount of waste leaching into the lagoon.
Measured Optimism
While the seagrass recovery is a positive sign, the ecosystem remains fragile. Nutrient pollution is still a persistent threat, and a single algal bloom could undo much of the progress made over the past few years. Climate change, rising sea levels, and increasing water temperatures also pose long-term challenges to the health of the lagoon.
To ensure the continued recovery of the lagoon, sustained efforts are needed to reduce pollution, improve water management, and protect vulnerable species like manatees. Local governments, environmental organizations, and residents must remain committed to safeguarding our estuary for future generations.
Photos Tell a Story
June 2016
Algae laden water laps the shore at Sewall's Point in Stuart, bringing business and recreational activities on and around its waters to a halt.
February 2022
FWC takes the unprecedented step of feeding lettuce to starving IRL manatees.
March 2023
Funds raised by MOEC (operated by FPUA), and Treasure Coast Manatee Foundation facilitate the first seagrass planting project in Moore’s Creek.
June 2023
Orca volunteers work on a buffered shoreline with plants grown in their nursery.
August 2024
FPUA receives grant funding toward phase two of its sewer treatment plant relocation from the shores of the lagoon to five miles west on the mainland.
January 2024
New legislation requires most residential properties located in certain proximity to the lagoon to convert from septic to sewer by 2030. Organizations like Clean Water Coalition have secured funding to offer financial assistance to homeowners.