Red tide was detected at levels described as “very low” on Longboat Key last week, according to the Sarasota County Health Department Healthy Beaches Program.
But a red-tide bloom that has impacted south Sarasota County has largely stayed away from Longboat Key.
Samples taken Monday, Oct. 8, revealed concentrations of Karenia brevis, the organism that causes red tide, of 5 cells per milliliter on Longboat Key. Concentrations of 5 to 10 cells per millimeter could cause possible respiratory irritation and shellfish harvesting closures.
Counts as high as 10,240 cells per milliliter have been reported on Manasota Beach. Levels more than 50 cells per milliliter can result in fish kills.
The Health Department, working jointly with Mote Marine Laboratory, conducts weekly red-tide cell counts. Sampling typically takes place Mondays, and results are usually released Wednesdays; more current counts were not available at press time.
Longboat Key Public Works Engineer Anne Ross said that the town is monitoring red-tide levels by keeping an eye on Sarasota County reports. If red tide were found on the island, the town would mobilize and pick up dead fish onshore.
The region’s last major red tide bloom occurred in 2007.
According to Mote Public Relations Coordinator Hayley Rutger, red-tide blooms are most common during early fall, although the red-tide organism is hardy enough to survive a wide range of temperatures.
“ … they can be present along Southwest Florida during winter or any other time of year, and they can sometimes persist for months and, in other cases, be short-lived,” Rutger wrote in an email. “We cannot predict when the current bloom will end, but the shorter-term wind-and-weather patterns can make a difference in how much it will affect our coastline.”
Rutger wrote that beach conditions can vary greatly with weather conditions. Even at beaches with medium-to-high concentrations of red-tide algae, winds may blow red-tide toxins away from shore. When one beach is experiencing red tide impacts, a nearby beach may not be affected.
For updated red tide counts by location, visit ourgulfenvironment.net/Red_tide_results.aspx. To monitor beach conditions, visit Mote’s Beach Conditions Report at mote.org/beaches.