It is not a bad start to the red tide season across western Florida, especially since no microorganisms have been detected off the southwest Gulf coast, where toxic algae blooms often occur during early fall.
But there are high concentrations along the Panhandle, especially in Bay and Gulf counties, affecting St. Andrews Bay and Mexico Beach. Here, authorities have warned beachgoers to stay off the water to avoid skin, eye and respiratory problems. They also advise against eating shellfish, as they may have become contaminated and be lethal. There have been fish kills in some areas.
The red tide is a harmful algal bloom caused by the naturally occurring alga Karenia brevis. When K. brevis appears in large quantities – typically in the Gulf – it can turn ocean water red, brown or green.
When this bacteria is present in the water, its contaminants deplete the oxygen, making it a fatal environment for in-water and waterfront residents and visitors. Red tides can have debilitating effects on marine life. If the microorganisms are concentrated at over a 10,000-cell-per-liter rate, fish of all kinds can start dying.
The toxic algae start building at microscopic scales well offshore. Warm waters and nutrients feed these microorganisms, and they often grow to high concentrations in the spring and summer months. The winds and currents drive the microorganisms to the coast, and when they form large blooms, the winds and currents can carry them for miles along the coast. While red tide occurs almost every year, its severity varies.
Red tide is also not limited to ocean waters. The toxic bloom has sometimes grown in canals, the Intracoastal and other waterways. If the conditions allow the microorganism to survive and thrive, it will grow and affect the water and the surroundings.
It impacts humans and nearby businesses, too.
Although not recommended, most people can safely swim in red tde. However, it can cause skin irritation and burning eyes. Inhaling the toxins can lead to coughing, sneezing, and teary eyes, though those symptoms are typically temporary. People with chronic respiratory conditions, such as asthma, are advised to avoid red tide.
While the medical effects on humans generally aren't serious, red tide is affecting the local economy in Florida: Some small businesses have temporarily closed in recent years. In seasons when algal blooms have been extensive in both distance and duration, many tourists have either changed destinations or canceled plans to visit the west coast of Florida.
La Niña and red tide
La Niña is present, bringing warmer-than-normal temperatures to Florida and its surroundings. Limiting the use of harmful fertilizers across the state, even in inland areas, could also help curb the growth of toxic algae. More nutrients and runoff can make these harmful algae blooms grow faster and more prominent.
