From: Armstrong, 1987; Britton and Morton, 1989
The Aransas Bay system lies on the Texas coast between the Corpus Christi Bay and San Antonio Bay estuarine complexes. The system is composed primarily of Aransas Bay and Copano Bay, but also includes Mission Bay and St. Charles Bay. Redfish Bay, to the south, is also closely associated with this system and is generally described within it, but is sometimes considered a portion of the Corpus Christi Bay complex. Freshwater inflow is provided by the Aransas and Mission Rivers and also by Copano Creek, although overall, freshwater influence is minimal. The bays are separated from the Gulf of Mexico by San Jose Island and water exchange takes place via Cedar Bayou and Aransas Pass.
Similar to San Antonio Bay, land use in the area is primarily agricultural- and ranching-based, and urban development is minimal. Coastal prairie and marshlands are common and the Aransas National Wildlife Refuge (see link below) is located within the boundaries of this estuarine system. The Mission-Aransas National Estuarine Research Reserve (MANERR) (see link below) was inaugurated in May 2006, including 751.8 square km of contiguous wetland, terrestrial and marine environments. It is the 27th research reserve and the only one in the Western Gulf of Mexico Biogeographic Region (from the East Matagorda Bay to the Rio Grande). Named for the two major rivers that flow into the area, the reserve contains public and private lands and waters. Its unique and diverse estuarine habitats in the western Gulf of Mexico support a host of endangered and threatened species including the endangered whooping crane.