September 28, 2005
Rita May Worsen Red Tide in South Texas
SOUTH PADRE ISLAND, Texas -- While Hurricane Rita struck days ago and hundreds of miles away, the storm is still creating problems on the southern tip of Texas.
Rita's path left South Texas hot and dry - conditions ideal for one of the worst red tides in memory - and swells from the storm have created fears that the toxic algae could spread.
"The red tide likes hot weather, it likes a certain salinity, it likes low wind," said Sonia Gallegos, a scientist at the Naval Research Lab at Stennis Space Center in Mississippi who has studied red tide for decades. "That's why we still have a red tide."
Tony Reisinger, a marine biologist at the University of Texas-Pan American Coastal Studies lab who confirmed its presence here Sept. 15, said swells from Rita breached the island at 11 places. He said that could send red tide blooms into the Laguna Madre, the popular fishing bay on the island's other side.
Trout, flounder, snook and other fish are washing up dead, along with smaller "filter feeders" that have been dying since the toxic algae first appeared more than a week before the storm.
Red tide occurs when algae known as karenia brevis proliferate, giving a reddish hue to the water. The blooms choke off oxygen in the water, destroying undersea life. The organisms also emit a toxin that paralyzes fish and causes discomfort for humans breathing the mist.
The bloom was so heavy in the days leading up to the hurricane that "we could actually taste it, which I've never experienced in my life before," Reisinger said. "It had a chemical taste to it."
Reisinger said red tide measured two to three times the level that's typically considered high.
The toxins in red tide can build up in the tissues of shellfish such as oysters clams, and scallops and may force delay or closure of the oyster harvest scheduled to begin Nov. 1, said Gary Heideman of the Department of State Health Services.
Red tide hurts fishing and tourism, and surfers enjoying Rita's southern ripples found red tide's mist uncomfortable.
"Man, it really burns your eyes," surfer Gene Gore said. "We pretty much surfed till we almost went blind."
If Rita had hit south of Matagorda Island, about the midpoint of the Texas coast, rains would have flushed South Padre's red tide out, Gallegos said.
Even though the red tide remains, Reisinger said it can be beneficial.
"It gives the ecosystem a rest when the fish are taken out of it," he said, adding that the alga is basically a plant that nourishes some marine life while killing others.
He said researchers also have extracted a chemical called brevenal from the algae that is being used to treat cystic fibrosis.
"It has harmful respiratory effects, yet it can be used to treat respiratory ailments," he said.