Next Steps for a Healthy Gulf of Mexico Watershed
Landscape at a Glance
The Florida Keys are a coral cay archipelago that extends about 100 miles from the southern tip of the Florida peninsula in an arc to the southwest and then west into the Gulf. The islands lie along the Florida Straits, dividing the Atlantic Ocean to the east from the Gulf to the northwest, and defining one edge of Florida Bay. Even though most of the land area in the focal area lies between two to three feet above high tide, the combination of marine and tropical upland habitats supports a wealth of biological diversity and habitats, including numerous endemic plants and animals. The coral reefs of the Florida Keys are the most extensive living coral reef system in North America and the third largest coral reef system in the world. Much of this system is protected as part of the Florida Keys National Marine Sanctuary, encompassing 2,800 square nautical miles of state and federal waters in the Keys. This marine protected area shares its conservation footprint with State Wildlife Management Areas, National Parks and NWRs that conserve the habitats that are home to federally listed species such as the Key deer, the American crocodile, the Lower Keys marsh rabbit, the silver rice rat and sea turtles, as well as native and migratory birds, butterflies and plants.
Major vegetation cover types include pine rockland, tropical hardwood hammock, freshwater wetland, mangrove forest and seagrass beds. The West Indian hardwood hammocks and pine rocklands are imperiled upland communities that include more than 120 species of hardwood trees, shrubs and plants. These forests are home to several endangered and threatened species including the Key Largo woodrat, the Key Largo cotton mouse, the Schaus swallowtail butterfly, the eastern indigo snake and the Stock Island tree snail. The mangrove forest ecosystem along the shoreline provides food and shelter to a myriad of marine organisms and shelter for diverse avian life. The shallow protected waters of Florida Bay and nearshore Atlantic waters support lush seagrass beds that serve as important nurseries for marine life and foraging grounds for wading birds.
The Keys have become less resilient over time and are losing ecosystem integrity due to the increasing environmental impact of factors such as climate change, invasive species, habitat fragmentation and poor water quality. Perhaps the greatest conservation challenge facing the Keys stems from rising sea levels; data show that the sea level in the area has risen nine inches in the last 100 years, and is expected to rise an additional three to six feet by the year 2100. Impacts from such a rapid rise in sea level include increasingly fewer upland areas as marine and intertidal habitats move upslope and displace native species, as well as diminished property values as inundation becomes more widespread and increasingly common. Additionally, an increase in nutrient loading in nearshore waters from land-based sources over the past few decades has resulted in decreased water clarity and unnatural algal growth, which greatly adversely affects nearshore coral reef communities. The Service believes that it is imperative that we quickly and collectively act on adaptive and sustainable conservation strategies to address these immediate threats to the Florida Keys.
The Florida Keys are home to a whole host of flora and fauna uniquely adapted to its insular environment. Many of these are distinctive subspecies that have evolved in isolation from their mainland congeners, are found nowhere else in the world, and are now endangered or threatened. Strategic land conservation and habitat management, particularly with potential climate change effects in mind, can aid in accomplishing recovery targets in these dynamic systems for several of these endangered species. Such targets are focused on stable populations with positive growth rates over time, such as for the Key deer (seven-year running), the Key Largo woodrat (three-year running average for six years), and the Lower Keys marsh rabbit (three-year running average for six years).
Numerous invertebrate species (e.g., the endangered Miami blue butterfly and the threatened Stock Island tree snail) and plants (e.g., the endangered Key tree-cactus and the threatened Garber’s spurge) are also endemic to the Keys and their habitats (e.g., tropical hammock and pine) need to be restored and conserved.
The subtropical climate of the Florida Keys also represents the northern range extent of even more species that are either federally listed or rare in the United States but that may occur more commonly in the Neotropics, such as the American crocodile, the West Indian manatee, the white-crowned pigeon, the mangrove cuckoo, and two threatened coral species, the staghorn and elkhorn. Restoring hydrology and protecting water quality will not only benefit some of these species, but will also benefit many waterbirds (e.g., the great white heron, the roseate tern and the brown pelican) with important nesting areas within the focal area.
Similar to aquatic restoration in the Southwest Florida Focal Area, the Service also has committed to restoring hydrology in in the Keys for many years. Federal trust resource species like staghorn and elkhorn coral stand to benefit from a watershed scale restoration effort that includes improvements in water quality and restores functional freshwater flow to the estuary by removing old roadbeds and promoting better practices for wastewater treatment. These actions and others that are already outlined in existing state-federal collaborative plans will improve conditions for many commercially and recreationally important marine fish like red drum, bonefish, and tarpon as well as invertebrate species like blue crabs, shrimp, and oysters. A large number of at-risk species also occur in the Florida Keys (e.g., sawgrass skipper, Key ringneck snake, Florida Keys mole skink, and the Lower Keys population of the striped mud turtle, among others); most would benefit from the priority actions described below.
High Priority Actions based on the Service’s Vision
Continue strategic land conservation efforts to ensure sustainable plant communities and quality wildlife habitats, particularly mangrove and pine rocklands habitat, and to build resiliency in preparation of accelerated effects of climate change and sea level rise.
- Coordinate with the state of Florida and Monroe County on their conservation land acquisition programs to strategically identify high-quality parcels and optimize land protection efforts to foster landscape conservation on private and public lands.
- Work with willing sellers to protect important wildlife habitats within approved acquisition boundaries of NWRs in the Keys.
- Work with partners to apply land conservation tools, such as conservation easements, partnership agreements, mitigation banks and technical assistance to protect, restore and manage priority habitats throughout the Florida Keys ecosystem.
- Work with the Peninsular Florida LCC, state and federal agencies, and other stakeholders to develop a Florida Keys adaptation strategy to anticipate the conservation needs of the future in light of increasing sea level rise and urbanization.
- Initiate planning for potential “ex-situ” or off-site conservation strategies to prevent extinction of species and subspecies endemic to the Florida Keys if conservation partners are unable to protect adequate habitat from impacts of sea level rise.
- Implement long-term monitoring of any translocated species and assess their impacts on their new habitat and associated species.
Enhance the biological diversity and resiliency of the fire-dependent pine rocklands and restore natural conditions and resilience of diverse habitats through frequent prescribed fire and/or control of invasive species.
- Work with state, federal, NGO and private land partners to implement frequent prescribed fire in fire-dependent habitats, especially pine rocklands where numerous federally listed plant species exist.
- Identify alternative treatments for maintaining stands of pine rocklands and reducing organic fuels where prescribed burning is no longer feasible due to adjacent, high-density urban areas.
- Through coordination with the Florida Keys Invasive Exotics Task Force and its member organizations, detect and monitor the presence, spread and damage caused by invasive non-native plants, particularly upon listed native plant and wildlife species, in order to develop priorities for eradication and/or control.
- Replace non-native plant species known to destabilize dunes and other coastal habitats with native species that are a natural defense against storm surge and coastal erosion which is likely to be exacerbated by sea level rise.
- Work towards the eradication of selected non-native plant specimens that represent exceptional threats to native habitats (e.g., mature individuals of white leadtree, Australian pine and Brazilian pepper found in hammock canopy openings).
- Work with landowners to control non-native seed sources from private lands and to increase coordinated mapping and monitoring of areas with known infestations of non-native plant species.
Restore hydrologic processes to improve water quality, water flow and tidal connections, and to enhance reef and adjacent coastal habitats, including mangrove forests, for the benefit of native fish and wildlife.
- Support implementation of landscape-level actions found in the Comprehensive Everglades Restoration Plan to enhance the water quality of Florida Bay, which will improve the overall health of the Florida Keys marine ecosystem, particularly seagrass and coral community habitats.
- Remove backfill from historic wetlands and restore hydrologic connectivity in degraded wetlands.
- Fill and plug ditches (e.g., former mosquito ditches) identified as essential to prevent unnaturally rapid infiltration of interior freshwater wetland, transitional and upland habitats by saltwater.
- Restore hydrological connectivity by removing obsolete roadbeds and installing culverts under actively used roads to facilitate the rapid drainage of storm surge waters, especially important in places where storm surge has become impounded and is causing damage to freshwater-dependent habitats and species. These restoration actions are also effective at reviving and restoring degraded mangrove forests.
- Monitor and assess the quality and quantity of subterranean freshwater lenses (i.e., layers of fresh groundwater that float on top of denser saltwater that arise when rainwater seeps down through a soil surface and then gathers over a layer of seawater at or down to about five feet below sea level) to determine the effects on fish, wildlife, and their habitats by saltwater intrusion caused by sea level rise.