Red tide linked to heavy rains, pollution runoff

What makes this year’s red tide so extreme? An expert tells us.

Although red tide is nothing new, we haven’t seen mammals die at this rate in years. Killed fish are normal causation.

The Florida Wildlife Commission reports that 80 tons of fish have been removed from beaches from Sarasota to Holmes Beach. More than 250 sea turtles have been found stranded or dead due to the red tide, and at least 80 manatee deaths are blamed on the red tide.

Mote Marine Laboratory says they get about 15 dead dolphins a year, so finding six in less than 24 hours is alarming.

Many of our viewers wonder: what makes this year’s tide so extreme? We put this question to Dr. Brian LaPointe, an expert in harmful algal blooms. He is also a research professor at Florida Atlantic University.

“If you go back in time, you will see a strong connection between nutrient pollution runoff and the red tide. For example, 1947 was a year of extreme rainfall. A massive hurricane that year caused flooding deadly,” LaPointe said.

He said Florida experienced an extreme red tide immediately afterwards.

“Once the rain hits the land, it causes runoff that eventually reaches the coastal oceans. These nutrients, along with heat, cause flowering.”

Factors include rain, nutrient pollution and heat. It’s something scientists call HAB, which stands for “harmful algal bloom.”

LaPointe says our recent red tide bloom was likely caused by Hurricane Irma as well as excessive rain in Florida during the last two weeks of May.

The last Great Red Tide we saw was in 2005, the same year as Hurricane Katrina. It was also a year after hurricanes Charley, Frances and Jeanne.

Once the bloom is over, there’s not much anyone can do to save the animals other than get them out of the area before the red tide hits. It is an almost impossible task, which is why there is no ongoing effort to do so.

The Florida Wildlife Commission will conduct tests to see if the dolphins found this week have been poisoned by the red tide. The results should come back in a few weeks.

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