AUSTIN,TX — The Texas Department of State Health Services is temporarily closing bays along the Texas coast from Matagorda Bay to Corpus Christi Bay to the harvesting of oysters, clams and mussels because of elevated levels of an algae that can produce a toxin in some shellfish. DSHS previously closed the Galveston Bay system to harvesting effective March 13 for the same reason. Commercial and recreational harvesters should not harvest oysters, clams or mussels from these areas until further notice.
The precautionary closure, which takes effect at midnight tonight, comes after DSHS personnel found elevated levels of Dinophysis algae along the coast. The toxin produced by Dinophysis, okadaic acid, can accumulate rapidly in the tissue of oysters, clams and mussels and cause diarrhetic shellfish poisoning, DSP, in people who eat affected shellfish. Symptoms of DSP include vomiting, diarrhea, nausea and cramping. It is not life threatening and does not generally cause long-term effects. Cooking does not destroy the toxin.
DSHS is not aware of any human illnesses at this time. Texas shellfish harvested before the closure does not pose an elevated health risk. The toxin does not affect other seafood, such as shrimp, crab or finfish.
Dinophysis occurs naturally in the sea and estuaries but is not usually found in high levels along the Texas coast. In 2008, 2010 and 2013, Dinophysis produced toxin in oysters and required DSHS to close harvesting in some areas.
DSHS will continue to monitor the affected waters and test oysters to determine when safe harvesting can resume. DSHS frequently opens and closes areas to harvesting for a variety of conditions, so harvesters should check the status of Texas bays by calling DSHS at (800) 685-0361. The approved areas of East Matagorda Bay, Lower Laguna Madre and South Bay remain open to harvesting at this time. The public oyster season ends April 30 in Texas.