The Texas Department of State Health Services announced that oyster harvesting in all Texas coastal waters is closed due to red tide, an algal bloom of Karenia brevis.

Red tide has been detected along the Texas coastline from Brownsville to Galveston. As a result, all Texas coastal waters are closed to the commercial and recreational harvesting of oysters, clams and mussels until further notice. Normally, the public can harvest oysters from Nov. 1 through April 30.

The algae contain a toxin that can accumulate in the tissue of oysters, clams, mussels and whelks and cause neurotoxic shellfish poisoning, or NSP, in humans who consume them. NSP symptoms can include nausea, dizziness, dilated pupils and tingling sensations in the extremities.

DSHS is advising people not to harvest and eat oysters, clams, or mussels from Texas coastal waters. Oysters can be toxic without any indication of red tide such as discolored waters, respiratory irritation or dead fish. People are also advised not to harvest and eat whelks from Texas waters as these species also accumulate toxin from the red tide organism.

The warning does not apply to other types of seafood such as shrimp, finfish, crabs or to commercial seafood products from other states or countries. Oysters in the market place that were harvested before the red tide began or from other states are not affected by this algal bloom.

The red tide toxin also can become aerosolized and cause coughing and irritation of the throat and eyes. People with respiratory conditions such as asthma may experience more pronounced symptoms. Respiratory symptoms usually subside when affected people leave the red tide areas.

DSHS will continue to monitor the red tide and will open areas to harvesting when it is safe to do so. For the latest information on the opening and closing of oyster harvest areas, call DSHS at 1-800-685-0361. For information on red tide, visit http://www.dshs.state.tx.us/seafood/redtide.shtm.

Rhonda D. Cummins ‘08
Coastal & Marine Resource
Advisor
Texas Sea Grant
College Program
http://kyakradio.tamu.edu