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发帖数: 2542 | 1 标 题: Fish kill linked to red tide
The Daily News
Published August 14, 2012
GALVESTON — Low to moderate concentrations of red tide, a neurotoxic algal
bloom, found in waters off Galveston might have caused the large fish kill s
een on isle beaches during the weekend, an official said Monday.
Hundreds of thousands of dead Gulf menhaden littered Galveston’s West End b
eaches Saturday and Sunday, prompting officials to initially speculate low d
issolved oxygen levels were to blame. Testing has revealed the presence of r
ed tide, officials said.There were no beach water advisories issued for swim
mers, and the Galveston Island Park Board of Trustees expected to have all b
eaches 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 acc
ess 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 westwa
rd 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 p
resence 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. Oyste
rs are harvested commercially in Texas only from November to April.
Red tide is a single-cell organism that accumulates in shellfish and can cau
se illness in people who eat them. Symptoms can include abdominal pain, naus
ea, 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 paraly
ze fish gills, leading to suffocation, he said.
In large concentrations, the algal bloom becomes visible as a brown or red d
iscoloration floating on the surface waters. No visible blooms have been rep
orted.
Strong winds can act as an aerosol, sending the bloom airborne, which could
cause beach-goers to experience eye or throat irritations, said Winston Dent
on of the Texas Parks and Wildlife Department’s Coastal Fisheries Division
in Dickinson.
Gulf menhaden, also known as shad, are more affected by environmental change
s 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 Galvest
on park board to help educate beach-goers. |
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