Workshop delves into red tide

By KEVIN LOLLAR, klollar@news-press.com
Published by news-press.com on February 28, 2004

A couple of recurring themes at Friday’s “Gulf in Distress” workshop:

• Red tide is probably aggravated by pollutants from land

• And policy makers need to start doing something about it.

About 100 people attended the workshop at Miramar Beach Club in Bonita Springs to hear scientists, elected officials and planners discuss red tide, red algae blooms and black water.

For some in the audience, the idea that pollution affects red tide was not news.

“Pollution coming down the Caloosahatchee has devastated the estuary,” said Capt. Pete Quasius of Time’s Fly’N Charters. “It would be naive to think nutrients flowing into the Gulf of Mexico are not affecting red tide and other algae blooms.”

Red tide is a natural phenomenon that occurs when an alga called Karenia brevis, or K. brevis, undergoes a population explosion or bloom.

K. brevis and other algae feed on nitrogen and phosphorus, which happen to be the main ingredients in fertilizers; waste water from phosphate mining also contains phosphorus.

Many scientists believe that a red tide bloom can begin offshore then increase when it comes into contact with nutrient-laden water flowing down rivers and streams.

Still, science doesn’t have all the answers, said Cynthia Heil, a senior research scientist at the Florida Marine Research Institute in St. Petersburg.

“We know that up to 90 percent of the phosphorus that red tide needs can be from rivers, and 20 percent of the nitrogen,” she said. “That’s telling us that these nutrients play a role, but that’s not the whole story. The other 80 percent of the nitrogen must be coming from something offshore.”

One source of nitrogen is an alga called trichodesmium, a plankton that lives throughout tropical and subtropical waters, including the Gulf, and tends to bloom right before red tide blooms, Heil said.

Questions remain unanswered because the first multi-discipline study of red tide didn’t start until 1998, said Richard Pierce, director of Mote Marine Laboratory’s Center for Eco-Toxicology.

“The focus of that work was from Port Charlotte to Tampa Bay,” Pierce said. “Red tide is still up there, but now it seems to be more prevalent down here. We need to shift the focus, but we can’t because we don’t have the money.”

Brian Lapointe, a senior research scientist at Harbor Branch Oceanographic Institute, pointed out that red tide blooms often happen during wet periods, suggesting that more rain means more runoff, and more runoff means more nutrients in the water.

“When water is dumped down the Caloosahatchee, that’s when you get your worst red tides,” he said. “That supports the correlation between runoff and feeding red tide blooms in near shore areas.”

The U.S. Army Corps of Engineers and South Florida Water Management District were criticized for dumping nutrient-rich water down the Caloosahatchee. One wag in the back of the room got a large laugh when he called the two agencies the “axis of evil.”

“You have to look at the big picture,” water district spokesman Kurt Harclerode said. “People here are concerned about the estuary and the Gulf, and so are we. But you have to take into consideration that the people around Lake Okeechobee depend on releases for flood control for their safety.

“We’re trying to balance everyone’s needs without causing adverse impacts.”

Now that evidence is growing that red tide and other harmful algal blooms can be affected by land-based pollution, something must be done, Lee County Commissioner Ray Judah said.

“There needs to be a drastic change in the mind-set of policy makers at the state and federal levels,” he said. “There has been an increase in the frequency and intensity of red tide in Lee County, but there’s not been a concentrated effort on the state and federal levels to resolve the problems.”

More research needs to be done, too, but that takes money, which is hard to come by, said Larry Brand, a senior research scientist at the University of Miami’s Rosenstiel School of Marine Biology and Atmospheric Science.

“Unfortunately, the funding often isn’t there until there’s a catastrophe,” he said. “Then you come in and do an autopsy.”