Study explores historic red tide levels along SWFL coast to determine severity

While the Gulf of Mexico is quiet a the moment, when it comes to red tide blooms, efforts to better inform beachgoers of the severity of these outbreaks are well underway. We looked at how researchers hope to gauge how bad the blooms are.

Wave after wave, and year after year, red tide seems to rear its head. But how do we know if one particular bloom is worse than another?

Dr. Barbara Kirkpatrick is a senior advisor with the Gulf of Mexico Coastal Ocean Observing System or GCOOS.

“So one of the things we get asked a lot when we have a red tide in town, is this one worse than the one we had in 2005?” Kirkpatrick said, “And, you know, we kind of struggled with that, like, how do you define worst?”

Dr. Kirkpatrick co-authored a study exploring just that by looking at red tide on Florida’s west coast between 1953 and 2019 and cell counts. She and other researchers came up with a “Bloom severity index.”

This chart offers a snapshot of those years. The darker red indicates higher concentrations along more coastlines. Also, keep in mind, testing for blooms has improved over the years.

Researchers also developed a respiratory irritation index.

Kirkpatrick explained, “We took the data that we have available, which is the cell count database that the Florida Fish and Wildlife Research Institute maintains for the state. And then the reports from the beach conditions reporting system maintained by Mote Marine Laboratory, and looked at those together over time to create this respiratory forecast index.”

Coupled with forecasting tools, the goal is to give beachgoers a better picture of conditions.

“We’ve created this respiratory forecast for the red tide aerosols again, not to keep people off our beaches during red tide, but to let them know when is a good time to go to the beach, and when’s not such a good time to go to the beach,” Kirkpatrick added.

Dr. Richard Stumpf, also with the study, says the work doesn’t stop here. “We need better information on the toxins in aerosol. So the symptoms are covered, but the aerosols by some reports can under some conditions go further inland than just the beach, and that means we need to have data on the actual toxins in these aerosols, which we don’t have now.”

The researchers are also passionate about this study because as more people move toward the coast, more people could be impacted by red tide blooms.