Red tide projections indicate no toxic blooms in the near future, but that could change

The Gulf of Mexico has been spared from red tide so far this year. The typical season for these toxic algae blooms is from late summer into fall.

"When we typically see the most blooms, just looking back historically, that would typically be in September, October, November,” said Kate Hubbard, who leads the red tide program at the Florida Fish and Wildlife Conservation Commission’s Fish and Wildlife Research Institute in St. Petersburg. She’s also the director for the FWC Center for Red Tide Research.

Hubbard said her team, along with the University of South Florida and the National Oceanic and Atmospheric Administration, is trying to forecast this year's situation.

"For this year, we would hope that it would be a short bloom — that's what we always hope. No bloom would be welcome," Hubbard said. "But in terms of where we're at what conditions are doing, we're still in the window where we might see something pop up pretty much at any time."

In the next few months, the scientists will be monitoring the Gulf of Mexico loop current, which can upwell nutrients from the continental shelf to nearshore waters. Nutrients feed the red tide microorganism Karenia brevis, which can lead to high concentrations considered bloom levels.

They’ll also be on the lookout for any changes in the water caused by drops in temperature through the fall, along with any tropical activity. These factors and more can either feed or suppress blooms.

But based on what the researchers are seeing now, Hubbard said it’s not likely in the near future.

“Our fingers are crossed that we'll have a little bit more time to prepare," Hubbard said. "There was one year in recent past, 2010, where we didn't have a lot of red tide. We didn't reach bloom levels. And so, it can happen where we have years where there's no bloom at all.”

During routine sampling of the Gulf, researchers recently noticed elevated peaks of chlorophyll, which raised concern that red tide blooms could be forming.

But after closer examination, the scientists determined it was a different type of microalgae. Hubbard said most algae are actually good for our ecosystems.

"They are important as photo synthesizers for producing the air that we breathe, and then also as the base of the marine food web,” Hubbard said.

But red tide blooms are a different story: they kill marine life, halt local tourism, and cause respiratory irritation — even neurological impacts — for some people, according to a recent study.

At this time last year, the Gulf was experiencing an ongoing bloom from the prior season.

There were a few different anomalies in 2021 that are still being studied, said Hubbard. That includes the Piney Point spill, in which more than 200 gallons of nutrient-rich wastewater were discharged from the former Manatee County phosphate plant into Tampa Bay due to a leaky reservoir that threatened the neighboring area.

Hubbard also pointed to some tropical activity.

“Some of the tropical storms that went through likely helped move the red tide around. What we don't totally know was whether there was a second event that initiated around the same time of year,” Hubbard said.

It’s unclear right now whether the yearlong event, which started in December 2020, was due to one bloom event or two, Hubbard said. And there are parallels between that event and the one in 2018, which lasted more than a year.

“We also had a decent amount of storm activity that seemed like it was coincident, when things were moving around, especially to the Panhandle. That happened in both years,” Hubbard said.

"And so that's one parallel that we'd like to look at more just in terms of thinking about whether we really have the same bloom that's moving around, or whether they're potentially different blooms and different initiation events, really, that we're looking at when they span that long."

Copyright 2022 WUSF Public Media - WUSF 89.7