TPWD News Release — March 22, 2004
The Texas Commission on Environmental Quality has contracted with TPWD to study three specific tidal streams, Cow Bayou, Tres Palacios River and Garcitas Creek. These streams are suspected of having low oxygen levels. Two other streams, Lost River and West Carancahua Creek, are believed to be healthy streams and they will also be studied and used for comparison.
There will be sampling done every six weeks. The biologists will make more sampling trips and collect more types of data than is typical for freshwater stream studies in order to try to understand how tidal streams work. They will then analyze the data and prepare a report, which is due to the TCEQ in 2006.
Tidal streams are areas where freshwater meets saltwater. They are freshwater streams that are influenced by the tide pushing up into them. Because they provide a special kind of habitat, tidal streams serve as nursery grounds for many types of fish and shellfish, including ecologically and economically important species like shrimp and sport fish. Adequate oxygen for fish and shellfish is critical for the health of these tidal streams.
The TCEQ has identified several tidal streams that may have inadequate amounts of oxygen for the long-term health of those streams. These streams were identified through regular monitoring and an assessment process required by the Clean Water Act. The process requires the state to analyze waters that may not have enough oxygen and determine whether the condition is natural or due to human influence. If the low oxygen condition is due to human influence, the state is required to conduct a "Total Maximum Daily Load" project to determine what needs to be done to control wastes that take oxygen out of the water.
When the fieldwork is complete, TPWD scientists will have about two years to analyze and interpret all the data and write a final report about the ecological health of each stream.