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Aquatic Preserves

Guana River Marsh Aquatic Preserve

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The Guana River Marsh Aquatic Preserve is situated on the northeast coast of Florida, nestled between Jacksonville and St. Augustine. The Guana Tolomato Matanzas National Estuarine Research Reserve (GTMNERR) Visitor Center, situated within the preserve, lies 10 miles north of St. Augustine.

HISTORY

In 1957, an earthen dam was constructed across the Guana River, resulting in the creation of Guana Lake. Recognizing the ecological significance of the area, the State of Florida acquired nearly 12,000 acres of the Guana Peninsula in 1984 for $48 million. This purchase, made through the Conservation and Recreation Lands and Save Our Coast Programs, aimed to protect the sensitive environment and its inhabitants, including endangered and threatened species. The Guana River Marsh Aquatic Preserve was officially designated in 1985. Later, the encompassing GTMNERR received its official designation on Aug. 19, 1999.

PUBLIC ENGAGEMENT OPPORTUNITIES

Volunteer Opportunities

The GTMNERR has a robust volunteer program that offers opportunities to participate in various activities, including:

  • Education programs
  • Biological surveys
  • Water quality sampling
  • Restoration activities

Visit the Friends of the GTM Research Reserve website for information on how to volunteer.

Events

Educational Opportunities

The GTMNERR provides educational programs at the preserve, including on-site and off-site educational activities. The visitor center has interpretive exhibits including live animals. There are also kiosks located along the trails on the Guana Peninsula which provide information about the ecology and history of the peninsula. For an up-to-date list of guided educational activities, visit the Friends of the GTM Research Reserve website.

SCIENTIFIC INFORMATION

The Guana River Marsh Aquatic Preserve, with a history of human interaction spanning over 5,000 years, holds a rich tapestry of archaeological significance. Within its boundaries and those of the larger GTMNERR lie 38 recorded archaeological sites, each offering a glimpse into the past. Among these are a burial mound, numerous shell middens with evidence of ancient meals and the remnants of a Spanish mission, possibly La Natividad de Nuestra Senora de Tolomato. These vestiges of past civilizations, ranging from the late Archaic period (2500-1000 BC) to the 19th century, underscore the enduring connection between humans and this unique environment.

The geological foundation of the Guana River Marsh Aquatic Preserve reveals a dynamic history shaped by ancient marine environments. The preserve's underlying strata predominantly consist of the Hawthorn Group, a Miocene-era formation characterized by a diverse composition of quartz sand, dolostone, phosphatic sediments and clay. This layer acts as a semi-confining layer above the Eocene limestones, the Ocala Limestone and Avon Park Formation, which form the upper reaches of the Floridan aquifer system.

Notably, the Oligocene Suwannee Limestone is absent in this region. The Hawthorn Group reaches its maximum thickness of approximately 150 feet under the preserve and gradually thins towards the south, reaching about 75 feet under the southern portion of the GTMNERR.

The Guana River Marsh Aquatic Preserve is a vibrant tapestry of interconnected habitats, supporting a remarkable array of wildlife. Its estuarine waters, nourished by the Guana and Tolomato Rivers, serve as a vital nursery for numerous commercially and recreationally valuable species, including oysters, shrimp, flounder, blue crabs, red drum and gag grouper. The waters of the preserve are also utilized by multiple shark species as a communal nursery, providing resources for ecologically important species such as the protected sandbar shark and the endangered scalloped hammerhead shark. The preserve's extensive salt marshes provide essential foraging and nesting grounds for wading birds and shorebirds, while its maritime forests offer shelter and sustenance for a variety of terrestrial animals. The preserve's high-energy beachfront, adorned with towering dunes, serves as a nesting haven for sea turtles and ground-nesting shorebirds. This rich mosaic of habitats underscores the ecological significance of the preserve, highlighting its role as a critical refuge for biodiversity in northeast Florida.

Wildlife Habitat and Ecosystem Type
Estuary, mollusk reef (oyster), salt marsh, mangrove, marine (open ocean), oyster rake

Nesting and Migrating Birds
Wood storks, clapper rails, painted buntings

Mammals
North Atlantic right whales, river otters

Reptiles
Green sea turtles, leatherback sea turtles, loggerhead sea turtles, diamondback terrapins

Fish
Red fish (red drum), blue crabs, Eastern oysters, scalloped hammerhead sharks, Atlantic brief squid, sandbar sharks

Other Species 
Plankton

Conservation Efforts

Conservation efforts in the Guana River Marsh Aquatic Preserve focus on preserving biodiversity, maintaining water quality and restoring degraded habitats. The preserve's designation as Outstanding Florida Waters highlights the importance of protecting its water quality from pollution and other threats. The GTMNERR is engaged in habitat management practices like prescribed fire to maintain a balance of habitats for the vitality of myriad plant and animal species. The GTMNERR also works to control non-native invasive species that can disrupt the balance of the ecosystem. The acquisition of the uplands surrounding the preserve, particularly the 1984 purchase of the Guana Peninsula, the Guana Buffer Preserve, has been crucial in protecting the watershed and preventing development that could negatively impact the aquatic environment. These conservation efforts contribute to the long-term health and resilience of the preserve, ensuring its continued ecological, economic and recreational value for future generations.

Ongoing Research

The GTMNERR has an active research program that includes long-term monitoring of water quality, weather and coastal wetland vegetation. Research in the preserve has focused on a variety of topics, including plankton and oyster ecology, fish distribution, alligator habitat use and diet and sea level rise projections. Ongoing research is critical for understanding the complex interactions within the ecosystem and for informing management decisions that ensure the preserve's long-term health.

Frequently Asked Questions

Year-round

Yes. For an up-to-date list of guided educational activities, visit the Friends of the GTMNERR website.

Yes. Aquatic preserves often are adjacent to other conservation areas that may have nesting birds or other easily disturbed wildlife. 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.

Follow current FWC saltwater fishing regulations.

Follow current FWC 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 up to eight people, annual passes available for purchase at the Visitor Center. The Friends of the GTMNERR accepts donations.

Learn how to get involved at The Friends of the GTMNERR website.

Partner Groups

The GTMNERR collaborates with a wide range of partner organizations to achieve its conservation and education goals. These partners include:

  • National Oceanic and Atmospheric Administration
  • U.S. Fish and Wildlife Service
  • Florida Fish and Wildlife Conservation Commission
  • St. Johns River Water Management District
  • University of Florida
  • University of North Florida
  • Friends of the GTM Research Reserve

These partnerships are essential for leveraging resources, expertise and community support to effectively manage and protect the preserve.