The Effects of Red Tide Exposure

The infamous red tide is an outbreak of toxic algae also known as karenia brevis. The current outbreak is spreading through the waters surrounding Florida and into the Gulf Coast.

Moreover, it appears that the red tide has been intensifying steadily over the years. While the primary effects of this toxic algae are suffered by the wildlife in these areas, humans can experience negative effects through exposure to it as well. Droves of wildlife were killed by the red tide in recent years, including numerous manatees, fish and birds.

Rick Scott, the governor of Florida throughout much of the outbreak, declared a state of emergency for several affected areas in August of 2018. This decision, coupled with current research efforts, may help to prevent the spread of health risks due to the presence of the karenia brevis in coastal waters. Learn more about the effects of ride tide exposure below.

What Causes Red Tide?

Red tide is a natural occurrence that has been plaguing the coast of Florida since the early 1800s. The warm temperatures and nutrient pollutants from the urban and agricultural runoff in this area aids in the manifestation of karenia brevis. When these factors combine, the algae begin to bloom aggressively and spread rapidly throughout nearby waterways.

The current resurgence of red tide is likely attributed to the recent tropical storms, which serve as a mode of transportation for the karenia brevis. Scientists have noted that these toxic algae can move through the water at a speed of approximately one meter per hour which makes it difficult to predict and control the spread.

Concerns surrounding the presence of red tide are attributed to the compositional makeup of the karenia brevis algae. K. brevis produces pollutants referred to as brevetoxins, which kill wildlife that has become exposed to the algae. In addition to killing marine life, brevetoxins are known to strip oxygen from infected waters and block sunlight from reaching the vegetation submerged underwater. As such, even if the marine animals do not come in direct contact with the algae itself, they may suffer from the lack of nutrients and oxygen in affected waters.

What Areas Are Affected by the Red Tide?

The current spread of red tide reaches almost 10 miles off the coastline of Florida, primarily surrounding Pinellas County on the Gulf of Mexico. Some of the cities affected by the red tide include Clearwater, Tampa and St. Petersburg. However, the southwestern coastline of Florida is seeing the most severe results of the red tide, with different areas receiving varying levels of exposure. The most prominent levels of red tide are found within the counties of:

  • Collier.
  • Lee.
  • Charlotte.
  • Sarasota.
  • Manatee.

According to the Florida Fish and Wildlife Conservation Commission, Bay County, located near Panama City, is the northernmost county affected by k. brevis. The extent of the algae spread in the Bay County region is significantly lower than the levels found further south, though the red tide is reportedly moving northward along the Gulf Coast.

What Are the Side-Effects of Exposure to Red Tide?

Exposure to red tide places wildlife at risk of death due to the constriction of oxygen and sunlight, as well as the direct toxicity of the algae itself. The current spread of red tide has led to the death of over 44 manatees in the month of August, adding to the total of 127 manatees thought to have been killed by k. brevis throughout 2018.

The Florida Fish and Wildlife Conservation Commission (FWC) reports that at least 10 dolphins have also been killed due to red tide exposure. Additional deaths caused by this algae have affected various wildlife grouping such as:

  • Bonehead sharks.
  • Bull sharks.
  • Hammerhead sharks.
  • Tarpons.
  • Birds.
  • Eels.
  • Goliath groupers.
  • Stingrays.
  • Sea turtles.

A critically endangered species of sea turtle, known as the hawksbill sea turtle, has been gravely impacted by the spread of red tide as well. Dead hawksbill turtles have been found washed up along the coast of Tampa.

The effects of this toxic algae bloom on humans is far less severe. Unlike other types of toxic algae, such as the cyanobacteria or blue-green algae, the red tide is not harmful to most humans. Most commonly, beachgoers may experience the “red tide tickle” which causes coughing and minor nose and throat irritation. Others may experience burning eyes or irritated skin after swimming in infected waters.

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Those who often experience skin or respiratory irritation should take precautions when visiting infected areas. This is because the breeze can also carry red tide toxins. Wearing items to cover the nose and mouth area is beneficial for those on the beach during an active red tide. Beachgoers with severe respiratory issues are advised to avoid exposure altogether to prevent breathing complications.

If you are experiencing any of these symptoms after being exposed to red tide, you are advised to thoroughly rinse your body and leave the area. Typically, once you leave the area any effects from the red tide wear off. If symptoms worsen, make sure to contact your doctor.

Note: Since the red tide is harmful to marine life, it is common to find dead fish floating in the water and washing up on shore. If you experience this, you are advised to avoid swimming in the water in order to avoid exposure to other types of bacteria.

What Is Being Done About the Red Tide?

During times of an active red tide, the FWC runs cleanup efforts and rescues wildlife caught within red tide exposure. In doing so, the scientists hope to control the level of algae found along the Gulf Coast to prevent the impact from widening. The FWC and other emergency services recently received approximately 1.5 million dollars in emergency funding to aid in the cleanup process.

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