Hurricane Ian Aftermath Still Lingers in Algal Blooms Detected in Four Counties Southwest Florida

Hurricane Ian has already gone but the aftermath lingers as harmful algal blooms were detected in four Southwest Florida counties.

Scientists are attempting to understand how storms affect red tide because the same thing happened in the wake of Hurricane Irma in 2017.

Since the event usually begins offshore and is then pushed east toward land, they are confident that storms are not the cause of red tide.

However, depending on how the wind or current moves the water and, more importantly, what's in that water, hurricanes may influence the intensity and location of red tides.

Runoffs and Blooms

Florida Gulf Coast University's Water School director, Michael Parsons, is worried about runoff agitating all the sediments and Hurricane Ian's impact on the growth of red tides.

In Tampa Bay, where red tide is getting too close for comfort, these worries are crucial.

Last week, bloom concentrations were found in 18 water samples from Southwest Florida.

According to the commission, at least one report of breathing difficulties, possibly caused by red tide, was recorded in Sarasota County last week.

Based on the most recent red tide predictions from the University of South Florida, over the next few days, very low levels of the red tide-causing karenia brevis will be drifting north from the Sarasota region.

As per Kate Hubbard, the Florida Fish and Wildlife Conservation Commission's Center for Red Tide Research director, it is still unclear whether the red tide will reach Tampa Bay.

Ian's Runoffs

According to Hubbard, it's also difficult to predict how Ian's massive runoff will affect the development of red tides.

Because its organism thrives best in saltier marine environments, Karenia brevis can consume a variety of nutrients and use them as fuel.

However, too much freshwater can also discourage red tide. In summary, Ian's runoff can exacerbate a red tide if there are already algae cells present, but it does not cause it.

According to images provided by Chuanmin Hu, an optical oceanography professor at the University of South Florida, satellite imagery on September 30, two days after Ian's landfall, showed hazy runoff accruing in the middle-lower Tampa Bay area after rainfall flooded the bay's tributaries.

Furthermore, according to Hu, runoff and discharges from rivers like the Alafia and Little Manatee rivers are what gives the water its root beer-like hue.

The absence of saltier water from such a runoff may also affect whether red tide levels in Tampa Bay significantly increase.

According to Parsons, when a body of water contains about one-third of freshwater, algal blooms won't develop.

The water may be too fresh if there is still a huge volume of runoff entering Tampa Bay, Parsons continued.

One of the few stations that continuously monitor salinity levels in the bay was damaged by the storm and was unavailable for the entire previous week.

One Thin Silver Lining

Red tide's recurrence in Southwest Florida has, at least temporarily, spared Florida's manatees, according to Carly Jones, the spokesperson for the Fish and Wildlife Research Institute.

Currents and Blooms

Red tide, which commonly flares up when there is a sustained ocean current from the southeast, is also affected by another factor.

That coastward current can be increased or decreased by a storm. Red tide is being pushed closer to the shore by currents.

Red tide conditions are best from September to January, which also happens to be part of the peak hurricane season. Red tide cells can be found in any given year, either before or after a storm.

Because of this, Yonggang Liu, the University of South Florida's director of the Ocean Circulation Lab, said it's difficult to predict whether this winter is going to be difficult for red tide.

Read also: Pristine Minnesota Lakes Probed for Mysterious Algae Bloom 

The Red Tide to Come

Irma did not cause the severe red tide that started to emerge in 2017, but Liu believes it could still have had an effect.

The red tide may have been brought on by numerous cold fronts because there was a nearly two-month gap between Irma and its appearance that year.

Liu noted that red tide blooms had been anticipated earlier this year. The absence of deeper, cooler ocean water surfacing in late spring, which was the first sign of red tide, was a precursor to what was to come.

Red tide cells that are present to the south may be introduced to the Tampa Bay area if the northward currents persist in the coming weeks.

However, Liu added that he does not believe that will occur and that, while Hurricane Ian's heavy downpours and drainage may have contributed nutrients to the ecological system in the coastal ocean, they did not fundamentally alter the situation, Tampa Bay Times reported.

Red Tides

According to the National Ocean Service, harmful algal blooms, also known as HABs, happen when colonies of algae grow out of control and harm humans, fish, shellfish, marine mammals, and birds in addition to other organisms.

Despite being uncommon, human illnesses brought on by HABs can be fatal or severely disabling.

Scientists prefer to use the term "harmful algal bloom" even though many people refer to these blooms as "red tides."

Nearly every summer, a HAB with national notoriety takes place along Florida's Gulf Coast. As the name implies, an algae bloom can cause the water to turn red.

According to My Water Earth & Sky, red tides can last just a few weeks or more than a year, and they may even pass over only to return later.

In the past ten or so years, some blooms lasted longer than a year before ceasing.

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