Fish kill linked to red tide

By Chris Paschenko, The Daily News
14 August 2012

 Stan Lewis of Dallas rakes dead fish away from his family’s tent at Bermuda Beach in Galveston on Sunday. Officials said a red tide could be responsible for the fish kill.  Photo by Jennifer Reynolds 

GALVESTON — Low to moderate concentrations of red tide, a neurotoxic algal bloom, found in waters off Galveston might have caused the large fish kill seen on isle beaches during the weekend, an official said Monday.

Hundreds of thousands of dead Gulf menhaden littered Galveston’s West End beaches Saturday and Sunday, prompting officials to initially speculate low dissolved oxygen levels were to blame. Testing has revealed the presence of red tide, officials said. 

There were no beach water advisories issued for swimmers, and the Galveston Island Park Board of Trustees expected to have all beaches cleaned of dead fish by Wednesday if there were no further fish kills. The park board brought in extra workers to clean Galveston’s 17 beach access points. 

Far fewer dead fish were found Monday on beaches along Galveston’s East End and at Crystal Beach on the Bolivar Peninsula, as the kill continued westward from as far away as Matagorda. 

Low to moderate concentrations of red tide, an algal bloom known as Karelia brevis, also were believed to have caused fish kills in Galveston Bay. The presence of the algae prompted the Texas Department of State Health Services on Monday to close what little oyster harvesting was ongoing by public lease holders in Galveston Bay, department spokesman Chris Van Deusen said. Oysters are harvested commercially in Texas only from November to April.

Red tide is a single-cell organism that accumulates in shellfish and can cause illness in people who eat them. Symptoms can include abdominal pain, nausea, vomiting, diarrhea and tingling in the hands and feet.

The name “red tide” originated from the discoloration of water associated with high concentrations of the algae, Van Deusen said. The algae can paralyze fish gills, leading to suffocation, he said.

In large concentrations, the algal bloom becomes visible as a brown or red discoloration floating on the surface waters. No visible blooms have been reported. 

Strong winds can act as an aerosol, sending the bloom airborne, which could cause beach-goers to experience eye or throat irritations, said Winston Denton of the Texas Parks and Wildlife Department’s Coastal Fisheries Division in Dickinson. 

Gulf menhaden, also known as shad, are more affected by environmental changes because they swim in such large schools.

The Texas Parks and Wildlife Department plans to continue testing the waters this week and to distribute red tide fact cards this morning to the Galveston park board to help educate beach-goers.