Everglades Ecosystem — Florida

The Everglades ecosystem is a vast, slow-moving subtropical wetland occupying the southern tip of Florida, historically spanning nearly 11,000 square miles from the Kissimmee River chain of lakes southward through Lake Okeechobee to Florida Bay. As documented by the South Florida Water Management District (SFWMD), the Everglades and Florida Bay system today covers approximately 2 million acres and constitutes the largest subtropical wetland in the United States. UNESCO designates Everglades National Park — established on December 6, 1947 and encompassing 1,508,976 acres across Monroe, Miami-Dade, and Collier counties — as the largest subtropical wilderness reserve on the North American continent.

Beginning in the early twentieth century, the construction of drainage canals, levees, and water control structures fundamentally altered the system's natural hydrology. The Thompson Earth Systems Institute at the University of Florida reports that only approximately 50 percent of the historic Everglades remains, and that over 70 percent of historic water flow has been lost. In response, the Comprehensive Everglades Restoration Plan (CERP) — authorized by the Water Resources Development Act (WRDA) of 2000 — is described by the University of Florida's Florida Museum as the largest hydrological restoration project ever undertaken in the United States.

The SFWMD describes the Everglades as a 'River of Grass': historically, rainfall collected across Central Florida, drained into the Kissimmee River, flowed into Lake Okeechobee, and then moved southward as an uninterrupted sheet of shallow water across the sawgrass prairies to Florida Bay and the Gulf of Mexico. The U.S. Geological Survey (USGS) documents that the underlying geology consists principally of limestone bedrock — rarely exposed at the surface — overlaid by a flat landscape of extensive peat and marl soils.

Today, as the USGS notes, water levels and patterns of flow are largely controlled by an extensive engineered system of levees and canals rather than natural precipitation. The University of Florida's Florida Museum documents that urban development, agriculture, and drainage projects have destroyed more than half of the original Everglades. The Everglades Agricultural Area (EAA), immediately south of Lake Okeechobee, occupies drained former wetland where sugarcane, rice, and dairy farming are practiced.

The USGS warns that the Greater Everglades ecosystem — covering much of South Florida — reaches maximum elevations of only a few meters above sea level, making it acutely vulnerable to sea-level rise. The FAU Center for Environmental Studies documents that salinity is expected to increase in coastal portions of the Everglades as sea levels rise, compounding the effects of altered freshwater flows. To monitor hydrology in real time, the USGS developed the Everglades Depth Estimation Network (EDEN) — an integrated system of 275 water-level gages providing 400×400-meter gridded daily water-level data across the freshwater Everglades.

Everglades National Park carries a combination of international conservation designations shared by very few protected areas globally. UNESCO inscribed the park as a World Heritage Site at 567,000 hectares, with the park subsequently expanded to 610,670 hectares. The Ramsar Sites Information Service records the park's designation as a Wetland of International Importance on June 4, 1987 — and its addition to the Ramsar Montreux Record of threatened Ramsar sites on June 16, 1993. The park also holds International Biosphere Reserve status, recognized in 1976. The USGS identifies it as the third-largest national park in the contiguous United States, while PBS Nature ranks it tenth-largest among all U.S. national parks.

The National Wildlife Federation documents more than 360 bird species in Everglades National Park, including wading birds such as the white ibis, glossy ibis, and roseate spoonbill. Federally threatened or endangered bird species present in the park include the snail kite, wood stork, and Cape Sable seaside sparrow. The Florida panther — identified by the National Wildlife Federation as the ecosystem's most endangered mammal — has a recovering population estimated at over 100 adult individuals, per PBS Nature.

The system is naturally oligotrophic — nutrient-poor. The SFWMD identifies phosphorus as the key chemical stressor: the Everglades evolved under ambient phosphorus concentrations of 10 parts per billion (ppb) or less, and even modest nutrient loading from agricultural runoff causes cattails and other disturbance-adapted plants to displace native sawgrass and wetland species.

The Comprehensive Everglades Restoration Plan (CERP), authorized by the Water Resources Development Act of 2000, is implemented jointly by the U.S. Army Corps of Engineers and SFWMD. The University of Florida's Florida Museum reports that CERP represents a more than $7 billion, multi-decade effort to address the quantity, quality, timing, and distribution of water throughout the Greater Everglades. The plan's framework — commonly abbreviated as QQTD — guides project sequencing across dozens of individual restoration components.

Phosphorus control has been a central investment. SFWMD's Stormwater Treatment Areas factsheet documents that Florida has invested more than $2 billion in phosphorus control infrastructure, constructing 57,000 acres of Stormwater Treatment Areas (STAs) — engineered wetlands that biologically remove phosphorus from agricultural runoff before water enters the natural system, with an additional 6,500 acres under construction. SFWMD's Water Quality Improvement data show that at least 90 percent of the Everglades now meets the ultra-clean 10-ppb phosphorus standard. Under a Restoration Strategies agreement with the U.S. Environmental Protection Agency, Florida committed to an additional 6,500 acres of new STA capacity and 116,000 acre-feet of additional water storage.

An upstream component of CERP, the Kissimmee River restoration, addresses damage inflicted by the 1960s channelization of that river. The Everglades Law Center documents this as a nearly $1 billion project authorized by Congress to restore more than 40 square miles of historic oxbow wetlands that were eliminated when the Kissimmee was straightened into a canal, disrupting the upstream hydrology that feeds Lake Okeechobee and, ultimately, the Everglades.

Burmese pythons (Python bivittatus), native to Southeast Asia, represent the most severe invasive-species threat to the Everglades ecosystem. The USGS documents that pythons are now distributed across more than 1,000 square miles of southern Florida from coast to coast, with the most severe mammal population declines occurring in the remote southernmost regions of Everglades National Park. Protected areas where pythons are documented include Biscayne National Park, Crocodile Lake National Wildlife Refuge, Big Cypress National Preserve, Fakahatchee Strand Preserve State Park, and Florida Panther National Wildlife Refuge.

A landmark 2012 study published in the Proceedings of the National Academy of Sciences documented severe declines in mammal populations throughout Everglades National Park coinciding with python proliferation, and found that approximately 25 percent of all pythons examined in the park contained bird remains — implicating rails, limpkins, grebes, herons, egrets, and the federally endangered wood stork. The SFWMD Python Elimination Program notes that pythons consume marsh rabbits, deer, wading birds, and alligators, thereby depriving native predators — including Florida panthers, raptors, alligators, and bobcats — of their primary food sources. The SFWMD operates the Python Elimination Program as one response to this threat, deploying trained contractors to remove pythons from public lands throughout South Florida.

The National Academies of Sciences, Engineering, and Medicine released its Tenth Biennial Review of CERP in 2024, identifying a historic level of restoration progress attributable to record state and federal investments in 2022 and 2023. The review found evidence of natural system improvement in large areas of the ecosystem, including the northeastern portion of Everglades National Park. The published report — the tenth in a biennial series dating to 2004 — also calls for incorporating Indigenous knowledge held by the Seminole and Miccosukee Tribes into CERP planning, and recommends applying climate modeling tools to anticipate the effects of climate change on restoration outcomes.

In July 2025, the State of Florida and the U.S. Army Corps of Engineers signed a landmark agreement to accelerate construction of the Everglades Agricultural Area (EAA) Reservoir, a central CERP component designed to store and route water south into Everglades National Park. Per the Florida Governor's Office, the agreement advanced the reservoir's completion timeline by five years — from 2034 to 2029 — and authorized Florida to construct the inflow and outflow pump stations. A subsequent groundbreaking for the Blue Shanty Flow Way — a component that will route water from the completed EAA Reservoir south into the park — was marked by the Governor's Office and SFWMD as a further milestone. The SFWMD notes that the EAA Reservoir is also intended to reduce harmful freshwater discharges to the Caloosahatchee River estuary to the west and the St. Lucie River estuary to the east.

The Everglades ecosystem is inseparable from Lake Okeechobee management: the lake functions as the hydrological hub connecting the Kissimmee watershed to the north with the Everglades to the south, and mismanaged Lake Okeechobee discharges degrade both the Caloosahatchee and St. Lucie estuaries. The SFWMD identifies the system as a vital component of the regional water cycle serving millions of residents in Miami-Dade, Broward, and Palm Beach counties, and the ecosystem's health directly affects the Biscayne Aquifer — the primary drinking water source for Southeast Florida. Degraded freshwater flow to Florida Bay drives harmful algal blooms that damage commercial and recreational fisheries throughout the Keys and coastal South Florida.

The Everglades intersects with Florida's agricultural sector through the Everglades Agricultural Area's sugarcane industry and its legacy of phosphorus-laden runoff. Invasive species dynamics — particularly Burmese pythons and invasive plants such as Old World climbing fern — relate to Florida's broader wildlife management and exotic species regulatory frameworks. The USGS warns that the few meters of maximum elevation across the Greater Everglades make sea-level rise an acute compounding threat to both the natural ecosystem and the coastal urban populations of South Florida. Florida's Seminole and Miccosukee Tribes, whose members have inhabited and used Everglades lands for generations, are identified by the 2024 Tenth Biennial Review as essential partners whose Indigenous knowledge the National Academies recommends integrating into future CERP decision-making.