By TERRY TOMALIN
© St. Petersburg Times,
published August 5, 2001
Tropical storms and hurricanes aren't the only environmental concerns for outdoor enthusiasts as the end of summer approaches.
Red Tide season is just around the corner. There is no need to worry, however. Florida Marine Research Institute in St. Petersburg has an aggressive monitoring program that will give anglers notice should a harmful algal bloom occur.
The program, which utilizes charter boat captains to collect data, operates statewide.
"We are approaching peak Red Tide season," Jay Abbott, the program's coordinator, said. "We can use all the help we can get."
To learn more about the program, go to the Institute's Web site at floridamarine.org or call Abbott at (727) 896-8626 ext. 1528. Meanwhile, here are answers to frequently asked questions, courtesy of the Florida Marine Research Institute:
What is Red Tide? It is a phenomenon resulting from dense concentrations (blooms) of a microscopic, plantlike organism that measures 1/1,000 inch. The toxin produced by the tiny cells can kill large numbers of fish, which can wash ashore. When the organism is extremely concentrated, water can have a reddish-brown color.
What causes it? The organism that causes the Florida Red Tide is a dinoflagellate called Gymnodinium breve. Because of its plantlike nature, G. breve responds to various environmental factors such as light, temperature, salinity and nutrients. These growth factors, along with other conditions caused by winds, tides and currents, determine how and where a bloom develops. Offshore, G. breve probably blooms annually as a part of its growth cycle.
How do you know Red Tide is in the water? FMRI scientists test for Red Tide algae by collecting samples in suspected areas. The algal cells are visible only through a microscope at a magnification of about 1,500 times. Scientists count the density of organisms per volume of water to determine the severity of the bloom. Some of the reasons to suspect Red Tide: the presence of dead fish, people experiencing respiratory impairment and discolored water.
Is there a way to control it? No method known will control Red Tide outbreaks in the wild. Blooms of related organisms have been controlled by the introduction of claylike material into Japanese waters. During the past 30 years, many theories have been proposed and some have been tested. Control of any species of organism in the open environment has the potential to adversely affect other organisms and must be approached with care.
How does it kill fish? The algae produces a toxin that affects the nervous system and the fish is paralyzed and can't breath. The first indication a bloom is in the area is usually dead fish. The slower moving or sedentary species generally are the most affected. The Red Tide algal cells respond to light and move up and down in the water column during the day and night. Therefore, fish can be affected at any depth.
Why can't I eat shellfish during Red Tide? "Shellfish" is a generic term used to describe a number of marine animals, not all of which are affected by Red Tide. Shellfish such as the bivalve molluscs -- clams, oysters and coquinas -- should not be eaten. They are filter feeders, straining out large amounts of Red Tide algae and concentrating it in their gut. Other "shellfish" such as crabs, shrimp and lobster can be eaten.