The Nation : Texas Red Tide Spreading

Hundreds of thousands of fish killed by spreading red tide piled up on Padre Island beaches as a state ban on clam and oyster fishing was extended both ways from Corpus Christi along more than 180 miles of Texas coast. In heavy concentrations, the microorganism imparts a reddish color to seawater, makes clams and oysters poisonous and can kill fish, shrimp and crabs, said Kirk Wiles, who oversees the state Health Department’s shellfish program. “It is moving to the south and has been moving to the south fairly rapidly,” said Wiles, who surveyed the coast by airplane. “Some areas are heavily, heavily impacted.” He said that oysters and clams infected by the organisms, while generally not lethal to humans, can cause numbness in the mouth and extremities.