SOUTH FLORIDA WATER MANAGEMENT DISTRICT A Map of the Caloosahatchee River Estuary (CRE) and watershed. The CRE and Greater Estuarine Area are highlighted in bright blue.

Often referred to as “Where the River Meets the Sea,” an estuary is a partially enclosed coastal body of water where fresh and saltwater sources mix. Our local estuary is the Caloosahatchee River Estuary (CRE), where freshwater draining from the land into the Caloosahatchee River meets saltwater from the Gulf of Mexico. Sanibel Island and most of the “Ding” Darling Complex are located outside of the estuary proper; however, they are considered as part of the “Greater Estuarine Area” because they are strongly impacted by the estuary.

WHY THEY ARE IMPORTANT

Estuaries offer an abundance of resources and services to the ecosystem and people alike.

VITAL HABITATS

The CRE is composed of multiple different habitat types, including submerged aquatic vegetation (e.g., seagrass, freshwater grass) beds, mangrove wetlands, oyster reefs, mud and sand flats, and shallow open waters. Many species of fish, mammals, birds and other wildlife are dependent on estuarine habitats to live, feed and reproduce.

The sheltered waters of estuaries act as critical nursery habitats for most coastal fish and invertebrate species, providing a safer, more stable place for their young to grow compared to the open ocean. Many of the beloved species found in the J.N. “Ding” Darling National Wildlife Refuge and surrounding waters — such as wading birds, Florida manatees, tarpon and snook — rely heavily on the CRE for food, shelter and nursery grounds.

ECOSYSTEM SERVICES

Our coastal communities, too, are intricately linked with and dependent upon services provided by the Caloosahatchee River Estuary. Wetlands, oysters and seagrasses help to improve water quality and clarity by filtering out nutrients and pollutants that drain into local waterways from urban, commercial and agricultural sources.

Mangrove wetlands and seagrass beds act as natural buffers to protect people and property from storm damage by reducing storm surge, flooding and wind speed. Further, our local economy depends on the health and natural beauty of our estuary and its resources. The CRE supports and impacts recreational and commercial fisheries, ecotourism, real estate, local tourism, restaurants and other business enterprises.

PROBLEMS IMPACTING ESTUARY REFUGE

When estuarine ecosystems are imperiled, so are we. Unfortunately, the ecosystem health of the CRW has been declining for decades due to many stressors. Future articles will explore the problems impacting the estuary and “Ding” Darling and how we can help conserve, protect and restore. Get to know your local estuary and invest in its health because we are all interconnected.

Avery Renshaw, Refuge Biological Science Technician is a biological science technician with the J.N. “Ding” Darling National Wildlife Refuge.