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The facts about Florida red tide, your questions answered

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SARASOTA, FL (WWSB) - Dead manatees, thousand of decaying fish on Sarasota beaches and an alarming number of deceased sea turtles washing up on shore; these are the images of red tide here on the Suncoast. 

>>For the latest info on which beaches are affected by red tide and the most recent weather forecast, as well as all of our red tide coverage, follow this link

Since the beginning of June, Sarasota, Charlotte, Lee and to a lesser extent Manatee County, have experienced a red tide bloom that has had a devastating effect on marine life and residents on the Gulf Coast.

But what do we really know about red tide? ABC7 decided to get to the bottom of red tide and answer your questions.

The Facts:

What is a Florida red tide?

According to the Florida Fish and Wildlife Conservation Commission (FWC), red tide is a harmful algal bloom, that is the result of higher-than-normal concentrations of a microscopic alga (plantlike organism).

Many algae species cause red tides all over the world, but in Florida and the Gulf of Mexico, FWC says the species that causes most red tides is Karenia brevis (K. brevis). Researchers identify K. brevis simply as Florida red tide.

Why does red tide occur?

Mote Marine Laboratory says Florida red tide needs three components to form a bloom: Biology, chemistry and the right physical conditions.

The organism must be present in the water (biology), the organism needs nutrients to grow (chemistry) and conditions have to be right in order to concentrate and transport Florida red tide.

Has coastal (nutrient) pollution caused the Florida red tide? (Discharge from Lake Okeechobee)

According to officials with FWC and MOTE, there is no direct link between nutrient pollution and the frequency or severity of red tides caused by K. brevis.

Florida red tide forms 10-40 miles offshore away from man-made nutrient sources. Red tides occurred long before human settlement says MOTE and severe red tides were observed in the mid-1900s before the coastlines were heavily developed.

Once red tides are transported inshore, MOTE officials say they are capable of using man-made nutrients for growth.

How does Florida red tide kill fish?

Karenia brevis kills fish by producing a potent toxin (called brevetoxin) that affects the central nervous system of the fish. The toxin can also affect birds, mammals and other marine animals MOTE says.

Additionally, wave action can break open K. brevis cells and release these toxins into the air, leading to respiratory irritation for people.

How long does Florida red tide last?

Red tides can last anywhere from a few weeks or longer than a year, they can subside and then reoccur depending on current conditions.

Can we control Florida's red tides?

At this time FWC says there is not a way to control or kill red tide.

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