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National Estuarine Research Reserves (NERRs)

Guana Tolomato Matanzas National Estuarine Research Reserve

NEWS     |     RESOURCES     |     CALENDAR

The GTMNERR stretches from Ponte Vedra to Palm Coast. The GTMNERR is known for its diverse ecological and cultural resources. It contains many unique features, such as a climatic transition zone, globally rare maritime hammock and coastal strand vegetation communities, and one of the few remaining natural inlets in northeast Florida.

The reserve boundary includes twelve distinct management units and is home to two Aquatic Preserves: Guana River Marsh Aquatic Preserve (GRMAP), and Pellicer Creek Aquatic Preserve (PCAP).

GTMNERR is one of 30 National Estuarine Research Reserves (NERR) protected areas established under the U.S. Coastal Zone Management Act of 1972 as a natural field laboratory. The National Oceanic and Atmospheric Administration's (NOAA) provides funding and guidance for the 30 reserves that make up the NERR System, while a state partner manages each reserve daily and works with local partners. The Florida Department of Environmental Protection is the managing state partner for the three Florida NERRs. GTMNERR specifically is a bar-built estuarine ecosystem featuring a variety of habitats.

HISTORY

The site selection process for Florida’s east coast NERR began in September 1991, with the identification of candidate estuaries in the Florida East Coast Carolinian and West Indian biogeographic regions identified by the NERR System. The Guana Tolomato Matanzas ecosystem was selected as the preferred alternative by a committee of scientists, environmental educators and coastal managers based on its overall potential for scientific research and environmental education opportunities and because of its relatively pristine condition. The GTMNERR was officially designated on Aug. 19, 1999.

PUBLIC ENGAGEMENT OPPORTUNITIES

Volunteer Opportunities

Volunteers can get involved with education and outreach, research assistance, estuary cleanups and more. Visit Friends of the GTM Research Reserve to learn how to get involved.

Events

  • State of the Reserve in late February
  • EstuaryFest in September, EstuScary in October
  • International Coastal Cleanup in September

Educational Opportunities

The GTMNERR offers engaging educational programs for K-12 and higher education students, both in and out of the classroom. The team makes GTM’s research data easy to understand and exciting. Programs blend GTM’s science, research and monitoring efforts to provide a comprehensive and locally focused educational experience. The reserve offers guided tours including exploration hikes, family seining, Matanzas Inlet walks and river to sea preserve walks. GTM also houses the GTMNERR Visitor Center at the Guana Preserve, which offers several educational opportunities. Educational programs include guided field trips for classes and teacher resources. Interpretive signs are located throughout the GTMNERR.

SCIENTIFIC INFORMATION

The appearance of the lands and waters within the GTMNERR is the result of a long interaction between humans and nature. The region is of special interest because of the comprehensive record of European settlement and landscape modifications beginning at an early date. The detailed records of the mid-16th century, Native American, Spanish, French, British and American inhabitants indicate that these cultures adapted in very different ways. Burning, clear cutting, plowing, dredging, filling, ditching and drainage are all evident throughout the historical record.

The first inhabitants of northeast Florida probably appeared during the Late Glacial Transition, 10,000 to 13,000 years ago. As sea level rise slowed to its pre-industrial rate, water resources, small game and plant resources became more accessible. This condition enhanced settlement in coastal locations.

By approximately 5,000 years ago the coastal environment of Florida had become similar to the present-day situation. 

The GTMNERR overlies strata common to northeastern Florida. Sediments interpreted to have been deposited during the Holocene include the recent barrier islands and beaches, and many of the lowland areas of salt marsh and mangroves. Quartz sand and shell fragments are common in the beach environments, with quartz sand and some clay found in the salt marshes. Older beach ridges interpreted to be Pleistocene, such as the Guana Peninsula, are coquinoid limestone of the Pleistocene Anastasia Formation, exposed on the southern beach in the GRMAP (east of Sombrero Creek) and are some of the older sediments and rocks in GTMNERR. The Anastasia Formation is also near the surface and exposed on several beaches from Matanzas Inlet southward, and along the Matanzas River and the Intracoastal Waterway in the southern portion of the GTMNERR. The Anastasia Formation is late Pleistocene. Due to erosion along the coastline during periods of lower sea level, the Anastasia Formation is not always present and GTMNERR has the most northern recognized coastal exposure of the formation.
 

From its geomorphological structure to the species found within, the area of the GTMNERR encompasses many unique features that make it an important site for ecological conservation, research and environmental education. The following list highlights some of the reserve’s significant features: 
• It is a bar-built estuary characterized by barrier islands that run parallel to the coastline, separated from the ocean. It also includes one of the few remaining natural inlets in northeast Florida, at the Matanzas River, which has never been dredged. 
• In contains large, contiguous stands of globally rare maritime hammock and coastal strand vegetation communities. 
• It serves as an important habitat for migrating species and as a critical feeding and resting location for migrating shorebirds and raptors along the North American Atlantic flyway. Many species find refuge within the reserve.

Wildlife Habitat and Ecosystem Type
Xeric Hammock, Mesic Hammock, Maritime Hammock, Hydric Hammock, Mesic Flatwoods, Basin Marsh/Marsh, Shell Mound, Beach Dune, Coastal Scrub, Salt Marsh, Marine Unconsolidated Substrate, Brackish Waterways, Mangrove Wetlands, Coastal Strand, Beaches, Open Ocean

Nesting and Migrating Birds
Least terns, painted buntings, wood storks, roseate spoonbills, bald eagles, oyster catchers and many more

Mammals
North Atlantic right whales, manateess

Reptiles
Three species of nesting sea turtles, American alligators, dusky pygmy rattlesnakes

Fish
Red fish (red drum), blue crabs, scalloped hammerhead sharks 

Other Species 
Multiple varieties of plankton, Eastern oysters, Atlantic brief squid

A full list of species can be found in the management plan.

Conservation Efforts

Estuaries stand as critical ecological hubs, and at GTMNERR, we recognize and celebrate their profound importance. The NERR is committed to studying and preserving these estuarine environments, as they play a crucial role in maintaining water quality, mitigating coastal erosion and acting as buffers against storm surges.

GTMNERR’s partnership with The Management Advisory Group and the Technical Advisory Group ensures that the latest research guides sustainable management practices. As a result, GTMNERR advances scientific knowledge while preserving estuarine ecosystems for nature and local communities. For example:

Habitat Conservation: Tidal wetlands in the GTM estuary are shifting from salt marshes to mangrove forests as a result of fewer hard freezes, which will change food webs and increase carbon storage. Ongoing research will help us understand how to protect these beloved habitats. 

Oyster Health Monitoring: The GTM estuary abundant oyster population plays an important role in water quality by filtering 60% of GTM's water every two weeks. GTMNERR staff monitor the health of the oysters and water quality to ensure these benefits endure.

Land Management and Conservation: Land managers look to the locally relevant research conducted at GTM to guide conservation practices such as prescribed fire and maintain coastal strand vegetation, a critical habitat type.

Ongoing Research

Water Quality and Weather:
As a NERR, staff at GTM monitor short-term variability and long-term changes in water quality and weather. Within the GTM boundary, there are SWMP four water quality stations: Pine Island, St. Augustine, Ft. Matanzas and Pellicer Creek. These data are essential to understanding the health of the estuary and informing research projects involving other aspects of the estuarine ecosystem, including plankton, wetlands, fish and more. Additionally, staff collect monthly water samples in the Guana River and Lake. 
Coastal Wetlands:
Coastal wetlands, including salt marshes and mangroves, provide nursery habitat for fish, crabs and shrimp; filter pollutants; absorb flood waters; and contribute to quality of life in Northeast Florida. Monitoring the health of these wetlands involves tracking vegetation changes, sediment elevation and shoreline erosion. Satellite imagery is used to track these habitats’ fluctuation and inform research on the recent expansion of mangroves into saltmarsh. Within the GTMNERR boundary, coastal wetland area has decreased over 25% since 1990. Scientists continue to study the drivers of this change and restoration techniques to mitigate the lost habitat. 
Plankton:
Plankton play a significant role in the estuarine food web and are sensitive to changes in water quality. Significant plankton population growth can lead to harmful algal blooms and fish kills. Like most research at the GTMNERR, scientists focus their plankton studies monitoring changes over time, determining what causes those changes, and assessing how those changes will impact the broader ecosystem including humans. 
Oysters:
Oysters and the reefs they form are culturally and ecologically significant in Northeast Florida. They provide habitat for fish, prevent shoreline erosion, improve water quality and are a food source for many animals, including humans. Staff researchers and volunteers monitor a set of oyster reefs within GTM every winter to monitor their condition and assess changes. 

Frequently Asked Questions

Year-round

Yes.

Yes. Dogs are allowed at the Guana Preserve on a leash no more than 6 feet away. Please do not let your pet run free in areas not designated for pets, and please pick up after your pet to avoid hazardous pathogens in our coastal waters. Aquatic preserves often are adjacent to other conservation areas that may have nesting birds or other easily disturbed wildlife. 

Follow current FWC saltwater fishing regulations: https://myfwc.com/fishing/saltwater/recreational/

Follow current FWC boating regulations: https://myfwc.com/boating/regulations/

Seagrass is protected within aquatic preserves; avoid shallow waters and raise motor if over seagrass. Damage to seagrass can result in a fine up to $1,000. 

Call Florida Fish and Wildlife Conservation Commission at 1-888-404-FWCC (3922).

ADA accommodations are specific to each access point and the managing entity for that site. 

$3 per vehicle at the Guana Preserve. Other sites within the NERR may have their own fees.

Learn how to get involved here.

Partner Groups