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Date of Issue: October 19, 2006

Red tide panelists agree much known, more data needed

Is the Florida red tide exacerbated by nutrients flowing into the Gulf of Mexico from shore?

A panel of experts wholeheartedly answered "yes" to that question during a forum on red tide held in Sarasota last week before a group of about 80 citizens.

"Yes, nutrients like nitrogen from coastal areas nearshore help exacerbate red tide," said Dr. JoAnn Burkholder, an algae expert from North Carolina State University.

"But you can't point a finger at it and say that is the cause of red tide," warned Dr. Cynthia Heil, who studies red tide at the Fish and Wildlife Research Institute in St. Petersburg.

Red tide in Florida is called Karenia brevis. It is a naturally occurring algae that is always found in the water at some level of concentration. For reasons as yet unknown to scientists, it occasionally "blooms" and can emit a toxic substance that kills fish and marine mammals and can cause respiratory distress in humans.

Burkholder knows first-hand about impacts of algae on humans. During research on red tide in North Carolina 15 years ago, she discovered a new strain of an algae, Pfiesteria piscicida, that was deadly to fish and harmful to humans to the level that she and her fellow researchers became seriously ill. The algae was later tracked back to its "trigger" - sewage - and the sewage source was the state's extensive hog industry.

The panel, including Island restaurateur Ed Chiles, also the chair of the group Solutions To Avoid Red Tide, and Mote Marine Laboratory Senior Scientist Dr. Richard Pierce, agreed that red tide blooms both worldwide and in Florida's waters have been increasing in frequency and distribution in recent years.

But all said that serious studies on the algae blooms were in their infancy, especially in Florida.

"Ten years ago, there was only $250,000 from the state for red tide research," Chiles said. "Today, there's about $4 million. We are starting to see some urgency from policy makers to study the cause and effect of red tide."

The effect of the throat-scratching, coughing element of red tide is more than just discomfort to beachgoers. Chiles said that a particularly strong and lengthy outbreak in 1995-96 nearly put his chain of three restaurants on Anna Maria Island and Longboat Key out of business during its nearly year-long tenure.

He added that he estimated a red tide bloom cost $20-$30 million to the economy through lost sales at restaurants, lost bookings at resorts and lost revenue from other coastal businesses.

"I know of two people who moved from this area because of the red tide blooms," Burkholder said.

And the group all agreed that much, much more data was needed in the study of red tide.

Heil said that her agency collects water sampling information from 70 different agencies in Florida to track red tide outbreaks. She is just now preparing to release findings from a four-year, $5 million study that looked at red tide booms, their possible causes, and methods to control the outbreaks.

"We know a lot more than you know what we know," Pierce said, and the findings will be published in various journals and publications within the next year.

The "trigger" of what causes red tide to suddenly bloom is still a mystery, although there are about 24 stated theories on the cause. Excessive nitrogen seems to feed the algae, but land-based nitrogen doesn't coincide with the usual bloom's start far out in the Gulf.

Recent reports of a bloom being spurred by underground springs and rivers transporting excessive levels of nitrogen into the far Gulf after the spate of hurricanes in 2004 is being studied, Heil said. However, historic analysis of hurricanes and red tide blooms don't appear to back up the theory, she said.

 Chiles cut to the chase on the issue when he said that regardless of what starts red tide, coastal pollution is doing no good to anything in the marine environment and should be cut back or eliminated.

And how can red tide be controlled once it bursts into bloom?

Pierce said there are a number of chemicals and agents that will kill red tide. Bleach works. So does ozone. Clay has been successful in other parts of the world to reduce the intensity of red tide. There are also biological elements that can be used to kill the algae.

"What's important, though, is to assess if it's ecologically sound, economically attainable, and logistically possible," Pierce said.

Several years ago, during a 500-square-mile outbreak of red tide off Tampa Bay, he estimated that if a ship were to make a 100-foot-wide swath through the bloom and spray something in the water to kill it, it would take about one year to cover the area.

"And one month later, the bloom was 5,000 square miles in size," he said.

Pierce suggested that red tide blooms be tracked, and warnings posted, similar to the way hurricanes are studied. "We need a strategic response strategy," he said.

"Red tide is a quality of life issue," Chiles said. "The beaches are the linchpin of our economy here."