Texas Parks and Wildlife Department
95 Fish Hatchery Road
Brownsville, TX 78520
Phone: 956-350-4490
Fax: 956-350-3470


Texas GEMS — South Bay Coastal Preserve

Site Description

The southernmost bay in Texas, located near Port Isabel. The bay consists of approximately 3,500 surface acres, bounded on the south by the riparian edge of the Rio Grande, on the north by the Brownsville Ship Channel and associated spoil banks, and on the east by Brazos Island. It is located in Cameron County.

Established Date: December 1984

Area of Influence:

12110208 - South Laguna Madre (USGS Hydrologic Units, Texas Maps).
4b - Estuarine Zone of Gulf Coast and Prairie Marshes(Ecoregions and Sub-regions of Texas).

Ecological and Cultural Characteristics

Habitat Type:

Emergent and submergent vegetation, in addition to extensive algal flats, are an integral part of the organic production and fertility of South Bay.

Rare/Endangered Species:

The rare/endangered/threatened species and natural communities located within or adjacent to the preserve include the following:

Breeding/Nursery Area:

Submergent vegetation is reported near the mouth of the bay, while emergent vegetation is found along the northwestern boundary and near the mouth of the bay. Extensive algal flats constitute a significant portion of the southern end of South Bay and are an essential part of the organic production and fertility of South Bay. The Bay supports 41 species of finfish and 9 different species of shellfish. The largest eastern oyster population south of Aransas Bay occurs in South Bay Preserve.

Forage Area:

There is an abundant forage species base in the preserve. Black mangroves occur together with cordgrass, particularly along the eastern shore. These stands of mangrove also have considerable importance to nesting waterbirds, such as the Roseate Spoonbill.

Migratory Species:

South Bay and its wind-tidal flats, shallow depths, associated vegetation, and unique location provides excellent feeding, resting and wintering habitat for numerous types of migratory bird species, such as the White Pelican, Brown Pelican, cormorants, Gadwall, Green-winged Teal, and Redhead.

Geomorphic Features:

South Bay lies between the riparian ridge along the Rio Grande to the south and the spoil banks of the Brownsville Ship Channel to the north; between the dune complex of Brazos Island on the east and wind-tidal flats and lomas on the west.

Ecosystem Function:

Diverse flora supports a diverse fauna (41 species of finfish and 9 different shellfish). Black mangroves along the shore have considerable importance to nesting waterbirds.

Uniqueness of Natural Community:

The preserve supports the largest concentration of oysters in the Lower Laguna Madre. There is evidence of a higher tolerance for salinity and turbidity in the South Bay oysters. Human activities are low in the Bay due to its remote location. South Bay has a rather disjunct water circulation and is relatively inaccessible. With the exceptions of large scale developments outside of South Bay proper, impacts of human activities are not immediately evident.

Current and Potential Use of the Site

Recreational Use: Boaters and anglers use the area on occasional and seasonal basis for waterfowl hunting (sparingly) and fishing.

Commercial Use: The bay supports considerable commercial oyster landings.

Management Status

The South Bay currently has a management plan written by the Texas Parks and Wildlife Department. The area of South Bay was patented land (government grant) belonging to the Brownsville Navigation District. On February 26, 1986 it was transferred to the GLO, who subsequently leased it to TPWD as South Bay Coastal Preserve. It is now the responsibility of the TPWD in coordination with the GLO.

Land Ownership:

South Bay is leased by TPWD from the GLO. Lands adjacent to the South Bay Coastal Preserve are either privately, locally, state or federally owned or administered.

Existing Designations: Texas Coastal Preserve

Existing Monitoring Activities:

In progress. South Bay is routinely surveyed as part of the TPWD Coastal Fisheries Branch standardized independent monitoring program to assess relative size and abundance of finfish and shellfish in Texas Bays.

Management Needs: Intergovernmental and private cooperation is essential to manage the unique ecosystems surrounding South Bay.

Sources of Information

Management Plan. 1989. Coastal Preserve System, South Bay, Cameron County, Texas - Texas Parks and Wildlife Department.