VENICE, Florida -- Inventor Bob Rigby has a secret formula to kill red tide without causing what he considers significant damage to other marine creatures.
But, Rigby said, he has grown frustrated, since he began research on his red tide cure seven years ago, over the reluctance of Mote Marine Laboratory and the Florida Fish and Wildlife Research Institute to fund the development of his invention.
"I said I had a cure for red tide and they didn't want anything to do with it," he said of the FFWRI.
He also said Mote scientists only offered to work with him on the research if he let them take credit for the discovery.
Richard Pierce, a Mote research director, however, said Mote couldn't work with Rigby because he refused to disclose the compound he uses to kill red tide organisms. Occupational safety rules require such toxic materials disclosures, he said.
Rigby also said a group called Solutions to Avoid Red Tide (START) was willing to support his research. But, Rigby walked away from the proposed partnership after the group altered a "non-disclosure" agreement he had drafted to eliminate his right to sue the group if it disclosed his secret formula.
So, last July, Rigby applied for patents for both the formula and an apparatus he designed to disperse it in the sea. He's also applied for a certification to seek patents in 26 other countries.
Now, his discovery is for sale to the highest bidder.
Only one problem.
The patent application for the formula was posted on the U.S. Patent Office's Web site. As a result, red tide treatment scientists around the world now can find out the formula's secret ingredient -- bleach.
Technically, the formula calls for either a 5-percent or a 15-percent concentration of sodium hypochlorite, which is commonly known as bleach. The remaining 95 percent or 85 percent of the formula consists of a solution of "contaminated water" including "unionized water, sodium carbonate and sodium chloride."
It's the concentration of the sodium hypochlorite with the contaminated water that makes the formula unique, Rigby said.
"To say it's just bleach isn't correct," he said.
But, to Bill Richardson, marine research associate for the FWRI, sodium hypochlorite is still bleach by any other name.
"(The patent application) talks about the killer compound and a dispensing mechanism, it talks about 5 and 15 percent sodium hypochlorite," said Richardson. "We use that to disinfect drinking water in emergencies ... We use it in the laboratory to disinfect, or to kill an organism."
Red tide, in local waters, is a bloom of a single-celled species of sea animal called Karenia brevis. The species produces a toxin that causes respiratory problems.
Each bloom can kill tens of thousands of fish, crustaceans and sea mammals. It also stinks up beaches with rotting fish and that chases many tourists away.
The problem with treating it with bleach is that the treatment is likely to cause collateral damage, Richardson said.
"It's a strong oxidant," he said. "It will inactivate certain cellular processes of bacteria. It will kill a lot of things."
Rigby, however, emphasizes that his goal is to disperse the chemical in concentrations high enough to kill red tide organisms but low enough to allow many other fish to survive.
Red tides were blamed for 112 porpoise deaths, 85 manatee deaths and 612 turtle deaths last year, Rigby pointed.
The loss of, say, 10 to 20 percent of the fish swimming within a red tide may be an acceptable loss in order to knock down the red tide with his formula, he said.
Another problem with dispensing chemicals to treat red tide is the massive volumes that would be needed, added Pierce, the Mote research director. He pointed out, at 10 parts per million, Rigby would need to dispense 50 million gallons to treat a typical Florida red tide bloom measuring 10 miles wide and 50 miles long.
Rigby, who also has invented a high performance curb and gutter cleaning machine, began his research on red tide in 1999 by hauling five gallon buckets of tainted seawater to his Nokomis garage.
Rigby has since teamed up with a science class at Venice High School to test the formula. Using beakers and other equipment loaned by FWRI, the students first tested the formula on red tide. They found a concentration of 5 parts per million to 8 ppm kills the organism.
The students also subjected damsel fish, silversides fish and opossum shrimp to the formula. They found those species survive higher concentrations, in some cases as much as 15 parts per million.
The trick will be to disperse the formula in seawater at just the right concentration that allows most of the fish to survive, Rigby said.
Rigby and the school are now working to get a local laboratory to replicate the research to confirm the results, he said.
"I think it does have potential," said Charlie Powell, a science teacher overseeing the testing. "The best thing would be prevention, but prevention would drastically affect the economy. That's the ideal but probably not approachable for a long, long time, if not forever."
To treat or study?
The idea of chemically treating red tide has been around since the late 1940s, when the state first tried dispensing copper sulfate by boat and airplane, said Richardson. The experiment was not well thought out, he said.
"It killed all the red tide, but it released a massive amount of toxins at once and that killed even more fish," he said. "It was not successful at all, in fact it made things worse."
In recent years, more state and federal funding has been directed to research methods to control red tide.
The shift to "mitigation" has come largely as the result of a lobbying effort by the group Solutions to Avoid Red Tide (START).
The money has been used to assess the economic impact of red tide, study human health risks, and create plans for a mitigation method using clay, a waste product of phosphate mining.
Red tide particles get stuck in the clay as it settles. The method is used in some countries in Asia. But, scientists still fear the toxins and other pollutants may get released from sediment.
Another method studied recently involved injections of ozone into the water. Ozone, however, kills indiscriminately.
Now, scientists have begun experimenting with bacteria and other biological processes to see if they could gobble up red tide organisms.
Meanwhile, Mote and FWRI are continuing research to detect red tide outbreaks and determine what causes them. Mote has developed its "Brevbuster" device, which gauges the concentration of red tide organisms.
And FWRI has recently funded a study of the nutrients that fertilize red tide.
Rigby said he feels the research industry has been spending funds on endless studies rather than developing ways to eliminate the bane.
Richardson, however, pointed out that any method to kill red tide would require knowing where it is blooming.
"To know that, you need research and monitoring, which is what Mote, FWRI and others are researching," he said.
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