Miami Mangrove Coastline — Miami, Florida

Miami's eastern boundary is defined by Biscayne Bay, a shallow subtropical estuary whose mangrove-fringed shorelines represent one of the most ecologically significant coastal features in the southeastern United States. The Florida Fish and Wildlife Conservation Commission (FWC) documents mangrove and salt marsh communities throughout the bay, with red mangroves (Rhizophora mangle), black mangroves, and occasional sawgrass communities forming the dominant fringe vegetation along the shoreline. The South Florida Water Management District's land-use and land-cover data from 2014–2016, as cited in the FWC coastal habitat report, maps this coverage across the Biscayne Bay area.

The NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML) identifies South Florida's shoreline as extensively lined with mangroves, situating Miami within a regional coastal ecosystem that also encompasses 350 miles of the only barrier coral reef in North America. The mangrove coastline connects northward through the city's urban waterfront and southward to Biscayne National Park and the Florida Keys National Marine Sanctuary — an integrated ecological corridor that NOAA monitors through three national parks: Biscayne, Everglades, and Dry Tortugas. Miami's coastal geography is further embedded in its civic and cultural identity: as Miami Waterkeeper documents, Coconut Grove resident Albert Gomez has described the mangrove rookeries of Biscayne Bay as 'literally where everything grows,' a phrase that reflects longstanding community awareness of the bay's ecological role.

The mangrove communities of Biscayne Bay perform a range of ecological functions documented across multiple authoritative sources. Florida Sea Grant (UF/IFAS Extension) reports that mangroves capture and store carbon, filter pollutants before they reach open water, stabilize shorelines against wave energy and storm surge, and provide nursery habitat for a wide array of species. The Florida Sea Grant publication states that 'nearly 80–85% of fish that we use recreationally and commercially are associated with mangroves.'

The FWC coastal habitat report documents the species dependent on Biscayne Bay's mangrove habitat, including goliath grouper, snook, snapper, tarpon, jack, sheepshead, red drum, juvenile lobsters, oysters, and shrimp. These species support both the recreational fishing sector and the commercial fishing economy directly tied to the South Florida coast. The bay's seagrass beds, documented in the FDEP Biscayne Bay Aquatic Preserve Draft Management Plan 2024, work in conjunction with the mangrove fringe: seagrass habitats in open water areas provide additional foraging and nursery functions that the intertidal mangrove communities alone cannot supply. Together, these natural communities form the productive base that supports an estimated $4.4 billion in economic activity and 43,000 jobs associated with the Florida Keys National Marine Sanctuary alone, as reported by NOAA AOML from 2019 data.

Miami's 20th-century development history involved substantial conversion of coastal mangrove habitat. The most extensively documented episode involves the construction of Turkey Point nuclear and natural gas power plant in southern Biscayne Bay. According to FWC coastal habitat research citing FDEP 2013 data, the construction of Turkey Point in the late 1960s and early 1970s required 270 kilometers (168 miles) of cooling canals to be built through approximately 2,750 hectares — equivalent to 6,800 acres — of mangroves adjacent to the plant. This single infrastructure project eliminated one of the largest contiguous mangrove forest areas in the Biscayne Bay system.

Beyond Turkey Point, broader patterns of coastal filling and waterfront development throughout the 20th century reduced historic mangrove coverage across Miami's urban shoreline. The cumulative effect of these losses — documented through successive land-use and land-cover mapping by the South Florida Water Management District — established the baseline against which current restoration programs measure progress. The FDEP's 2024 Biscayne Bay Aquatic Preserve Draft Management Plan identifies the restoration of degraded mangrove and coastal wetland habitat as a continuing management objective, while also noting that heavy watercraft traffic in the bay remains a key ongoing pressure on the preserve's natural communities.

The primary protective designation for Miami's mangrove coastline is the Biscayne Bay Aquatic Preserve, a Florida Aquatic Preserve administered by the Florida Department of Environmental Protection (FDEP). The FDEP's 2024 Draft Management Plan — updated through a public review and advisory committee feedback process that continued into January 2025 — identifies the preserve as ecologically significant for mangrove habitat, seagrass beds, and water quality. The plan describes the bay as 'surrounded by the vibrant City of Miami' and notes that heavy watercraft traffic constitutes a primary management challenge.

At the federal level, NOAA's AOML conducts integrated ecosystem monitoring across the South Florida network, linking Biscayne Bay's health to the broader corridor extending through Biscayne National Park, Everglades National Park, and Dry Tortugas National Park. This monitoring framework treats the mangrove coastline not as an isolated feature but as a component of a connected subtropical marine system. The FWC's Coastal Habitats in Managed Marine Protected Areas program, documented in its chapter on Biscayne Bay, provides species composition and habitat mapping data that inform both FDEP management decisions and local restoration planning. The South Florida Water Management District contributes land-use and land-cover data — most recently mapped for 2014–2016 — that tracks changes in mangrove coverage over time.

Active mangrove and coastal wetland restoration in the Biscayne Bay region involves a combination of county, state, federal, and nonprofit partners. A prominently documented initiative is the Cutler Marsh restoration project in South Miami-Dade, adjacent to Biscayne National Park. According to a Miami-Dade County official press release, the county received a $330,000 grant from the National Fish and Wildlife Foundation (NFWF) for this project. Combined with a $437,142 match contributed by Miami-Dade County, the Town of Cutler Bay, the South Florida Water Management District, and volunteer labor, total project investment exceeded $767,000 for the restoration of coastal wetland and mangrove forest at Cutler Marsh.

In the City of Miami Beach, the Rising Above program has implemented living shorelines at multiple city parks, combining structural seawall elements with mangrove planting. Miami Beach describes the design at Brittany Bay Park as the first hybrid structural seawall with a living shoreline in the city. Additional parks where the program has implemented living shorelines include Maurice Gibb Memorial Park, Muss Park, and Pinetree Park. Florida Sea Grant documents living shorelines as a design approach that integrates mangroves with other coastal engineering elements to provide both ecological services and shoreline stabilization.

Two City of Miami policy developments have directly shaped the trajectory of mangrove conservation along its urban shoreline. The first involves a proposed City Commission ordinance that would have banned the planting of mangroves in city parks. Miami Waterkeeper reports that the ordinance was withdrawn following community and scientific opposition, preserving the city's capacity to incorporate mangroves in its parks and public green spaces.

The second development concerns the city's response to a U.S. Army Corps of Engineers proposal for a $4.6 billion sea wall along the Biscayne Bay waterfront. The Corps' original design called for a 20-foot wall along the Brickell waterfront. Miami Waterkeeper reports that the City of Miami requested the Army Corps revise the proposal to incorporate a green hybrid design that includes mangroves, opting against the hard-wall approach in favor of nature-based coastal infrastructure. This policy direction aligns with the living shorelines framework documented by Miami Beach's Rising Above program and Florida Sea Grant.

These municipal decisions reflect a broader documented pattern in which mangroves are being reconsidered not solely as passive ecological features but as active components of climate resilience infrastructure. The FDEP's 2024 Biscayne Bay Aquatic Preserve Draft Management Plan situates this trajectory within a longer-term management framework for the preserve, with the January 2025 public review process continuing the formal mechanism for community and stakeholder engagement.

Miami's mangrove coastline does not function as an isolated urban feature. The bay's ecological continuity with Biscayne National Park to the south places the city's shoreline within a federally protected marine system, while the northward extension of the Everglades watershed connects freshwater flows from the interior to the estuarine conditions on which mangroves depend. NOAA AOML documents this integrated character through its South Florida ecosystem restoration monitoring program, which treats Biscayne Bay as one node in a regional network spanning Biscayne, Everglades, and Dry Tortugas national parks.

The economic dimension of this regional connection is substantial. NOAA AOML reports that in 2019, the Florida Keys National Marine Sanctuary — which receives water and species that move through Biscayne Bay — contributed $4.4 billion and 43,000 jobs to the Florida economy. This figure indicates the scale of economic value flowing from the coastal ecosystem corridor in which Miami's mangrove shoreline is embedded. Miami-Dade County's partnership with the Town of Cutler Bay, the South Florida Water Management District, and the National Fish and Wildlife Foundation in the Cutler Marsh restoration project, as documented in the county's official press release, illustrates the multi-jurisdictional character of mangrove restoration across the broader Biscayne Bay watershed.