Could a hurricane be the cause of Florida's red tide?
Thursday, August 16, 2018, 3:39 PM - The red tide is nothing new in Florida. It has been affecting the west coast beaches for 10 months, but the situation worsened this month.
The situation has gotten so bad that Governor Rick Scott has declared a state of emergency for several counties.
The "red tide" of microscopic algae off 160 km of the state's southwestern Gulf Coast has littered beaches with dead fish and killed sea turtles and manatees. It's also caused respiratory problems in some people.
The red tide is a collection of microscopic algae that is often red when in high concentrations and it produces toxins than can harm, and sometimes kill, sea life. It has been doing just that. The algae blooms that start about 20 km offshore occur naturally and travel by winds and currents.
HOW DID THIS HAPPEN?
Hurricane Irma made landfall in September 2017 in two Florida locations only to be followed by the beginning of the red tide. Due to the copious amounts of rain that fell throughout the state, the largest lake - Lake Okeechobee - filled to alarming levels. As a result, the U.S. Army Corps of Engineers was forced to release massive amounts of nutrient-laden water from Lake Okeechobee to prevent the over-topping of the Hoover Dike.
Could this runoff be blamed for the prolonged Red Tide we are witnessing now? Scientists are still trying to figure this out.
HOW LONG CAN THIS GO ON?
According to NOAA, when (and if) the current bloom will end remains an open-ended question.
Red tides can last as little as a few weeks or longer than a year. They can even subside and then reoccur.
In 2005, for example, a bloom started off the coast of St. Petersburg, Florida, in January and then spread to Pensacola and Naples by October, persisting for the majority of the year. The duration of a bloom in nearshore Florida waters depends on physical and biological conditions that influence its growth and persistence, including sunlight, nutrients, and salinity, as well as the speed and direction of wind and water currents.Researchers are watching oceanographic conditions in the region carefully and using forecasting tools not unlike seasonal weather forecasts to predict how long this bloom will last.
HOW DANGEROUS IS THE RED TIDE?
The Florida red tide organism, Karenia brevis, produces potent neurotoxins called brevetoxins that can affect the central nervous system of many animals.
This can be fatal, which is why red tides are often associated with fish kills.
Mortalities of other species, including manatees, dolphins, sea turtles, and birds also occur.
Wave action near beaches can break open K. brevis cells and release the toxins into the air, leading to respiratory irritation. For people with severe or chronic respiratory conditions, such as emphysema or asthma, red tide can cause serious illness. People with respiratory problems should avoid affected beaches during red tides.
Additionally, the red tide toxins can also accumulate in filter-feeders mollusks such as oysters and clams, which can lead to Neurotoxic Shellfish Poisoning (NSP) in people who consume contaminated shellfish.