The San Antonio Bay estuary system is located on the mid-Texas coast and depends on freshwater inflows from the Guadalupe and San Antonio rivers. The rivers converge and enter the estuary through a single channel at the head of the Guadalupe Delta.
Bordered in part by the Aransas National Wildlife Refuge, the winter home for the last wild flock of the endangered whooping crane, San Antonio Bay provides an abundance of important habitat for fish and wildlife. The whooping crane’s recovery from the brink of extinction is one of the nation’s best-known conservation success stories. But the future of the whooping crane remains uncertain and depends in large part on the future health of the bay. The whoopers’ winter diet is made up largely of blue crabs. In years when freshwater inflows are low, the availability of blue crabs decreases, causing stress and increased risk of mortality for the cranes.
Additionally, oysters, shrimp, striped mullet and menhaden are among the species whose populations would decline without adequate freshwater inflows. Indirectly, birds and other wildlife that feed on these species could also be affected. Unfortunately, Guadalupe River flows are seriously threatened by population growth and increasing water use upstream.
The land near the bay consists largely of grassy prairies and is mostly used for agriculture. In addition to reduced freshwater inflow, San Antonio Bay has experienced habitat loss and fragmentation. Investments in strategic habitat conservation will complement other restoration efforts.