TALLAHASSEE, Fla. — Residents along Florida’s Gulf Coast, still recovering from recent hurricanes, are facing a new environmental concern: a potential outbreak of harmful algae bloom along the state’s southwestern shoreline.
Satellite images indicate the presence of an algae bloom stretching alongside Florida’s western coastline near Tampa. However, experts warn that the recent hurricanes, Helene and Milton, have delayed regular monitoring needed to accurately assess the situation. Currently, federal authorities have stated there is “no risk of respiratory irritation” from red tide in the area.
Red tides, characterized by excessive growth of specific algae species, can release toxins that are harmful to marine life and can also affect human health. “The density of the algae can discolour the water, giving rise to the term red tide,” explained Beth Stauffer, a biology professor at the University of Louisiana at Lafayette.
The primary species behind the blooms in Florida’s Gulf Coast is Karenia brevis, a single-celled organism that creates powerful neurotoxins capable of being aerosolized, posing health risks to beachgoers, especially those with respiratory issues. “It affects not only fish and marine mammals but can also endanger human health when toxins become airborne and irritate individuals with health vulnerabilities,” Stauffer elaborated.
Following the impact of Hurricanes Helene and Milton, scientists believe the storms might be exacerbating the growth of pre-existing toxic algae. Here’s an overview of what red tide is and how hurricanes can influence its occurrence.
Red tides, referred to by scientists as harmful algae blooms, occur when aquatic microorganisms proliferate uncontrollably, producing toxins that can be lethal to fish, render shellfish inedible, and make the air unbearable. While various microorganisms can trigger toxic blooms globally, Karenia brevis is identified as the primary culprit for the recurring blooms in southwestern Florida.
These algae blooms are typically observed every year in late summer or early fall, coinciding with warmer temperatures and favorable wind conditions that foster algae growth.
Although hurricanes are not the direct cause of red tides, they can influence their severity. Experts point out numerous factors affecting harmful algae blooms, including nutrient availability, wind patterns, and ocean currents vital for the marine food chain. While there is no consensus on whether hurricanes can disrupt algae blooms, it is agreed that they can enhance blooms’ intensity by disturbing nutrient-rich waters that support microorganism growth.
“Hurricanes bring up deeper waters in the Gulf of Mexico rich in nutrients. They can also produce significant rainfall that contributes additional nutrients through runoff,” commented Richard Stumpf, an oceanographer with the National Oceanic and Atmospheric Administration. “Such conditions tend to amplify an existing bloom.”
In some cases, hurricanes can transport these blooms inland, pushing them vast distances along the coast. Stumpf noted, “An extreme example is Hurricane Katrina, which, although it didn’t significantly impact Florida, managed to shift a bloom from southwest Florida to the Panhandle due to its size.”
What health risks do these blooms present? Harmful algae blooms can present serious threats to aquatic life, often resulting in significant fish die-offs that wash up on shores. Exposed individuals may experience various symptoms, including coughing, dizziness, and difficulty breathing. “It’s similar to an instant cold—just passing over the dune can trigger coughing and watery eyes,” Stumpf remarked. “However, once I leave the area, I usually feel fine within ten minutes,” he added, highlighting the transient nature of the symptoms.
For people with asthma or respiratory conditions, the effects can be more severe, sometimes requiring medical intervention. Additionally, pets interacting with toxic algae can suffer serious health consequences or even face fatal outcomes.
Currently, monitoring data indicates that moderate to high levels of Karenia brevis have been observed in certain coastal areas near Pinellas County, coinciding with the landfall of Hurricane Helene in the Big Bend region. A forecasting tool from NOAA reveals there is presently “no risk of respiratory irritation” linked to the red tide algae in Florida.
Researchers have faced delays in collecting and interpreting data due to the storms. “It seems the hurricane may have inadvertently facilitated the development of a red tide bloom along the coast,” remarked Robert Weisberg, an emeritus professor at the University of South Florida. “However, we have yet to sample the area to ascertain the bloom’s specific characteristics.”
