St. Marys River/Sea Islands

St. Marys/Sea Island program area St. Marys River © St. Johns River Water Management District

Three large rivers meander through the upper east corner of Florida and spill into the Atlantic Ocean within a few miles of one another. On their way through northeast Florida, these rivers branch, fork and periodically flood, creating an extraordinary coastal marsh system. The St. Marys River/Sea Islands region is characterized by the confluence of these rivers—the St. Marys, St. Johns and Nassau. These remarkable lands and waters lie within close proximity to the city of Jacksonville, which is fast becoming one of the largest metropolitan areas in the country.

Rare Wildlife and Plants

• right whale
• red-cockaded woodpecker
• peregrine falcon
• Florida black bear
• wood stork
• roseate spoonbill
• West Indian manatee
• sea turtle
• gopher tortoise
• Florida toothache grass
• Bartram’s ixia
• longleaf pine

Threats

• Jacksonville continues to experience rapid growth, and its natural areas continue to be fragmented and damaged by development and unsustainable timber practices.
• Changes in water quality, caused by hydrologic alterations and pollution, are threatening the region’s aquatic systems. 
• A significant rate of residential septic failure is an increasing source of water pollution in the area’s rivers.
• A lack of fire has degraded wildlife habitat and increased the risk of devastating wildfires.

St. Marys River © St. Johns River Water Management District

• The Conservancy has helped protect more than 123,000 acres in the region.
• On behalf of Jacksonville’s Preservation Project, the Conservancy helped the city establish the largest urban park system in the nation.
• Working with partners across political boundaries the Conservancy is addressing threats to the St. Marys River, supporting healthy river management and protecting buffers along the corridor. 
• The Conservancy has helped secure conservation easements protecting miles of river shoreline from development.
• Timberlands comprise 80 percent of the St. Marys River watershed. The Conservancy is working with timber companies and private landowners to promote sustainable forestry practices.
• The Conservancy has joined with several agency partners to increase the number of prescribed fires on protected lands in order to help restore wildlife habitat and reduce the risk of catastrophic wildfires in the region.
• The Conservancy promotes regional land-use planning and environmentally sensitive development along the river.

Machaba Balu Preserve
The Conservancy’s Machaba Balu Preserve protects more than 10,000 acres of tidal salt marsh and 77 upland islands within the 47,000-acre Timucuan Ecological and Historic Preserve. The islands preserve is being managed in partnership with the National Park Service and are open to the public for passive recreation.

For More Information
For more information about the St. Marys River and Sea Islands, call The Nature Conservancy’s Northeast Florida Program office at (904) 598-0004.