Red Tide Information

What is red tide?

A red tide, or harmful algal bloom, is a higher-than-normal concentration of a microscopic alga (plantlike organism). In Florida and the Gulf of Mexico, the species that causes most red tides is Karenia brevis, often abbreviated as K. brevis. At high concentrations, the organisms may discolor the water, sometimes red, light or dark green, brown or the water may appear clear.

What causes red tide?

A red tide bloom develops when biology (the organisms), chemistry (natural or man-made nutrients for growth) and physics (concentrating and transport mechanisms) interact to produce the algal bloom. No one factor causes the development of a red tide bloom.

Where can I check the status of red tide at my local beach?

Local Beach Conditions or call 1-941-BEACHES (Press 10 for Charlotte County conditions)

Are red tides new?

No. Red tides were documented in the southern Gulf of Mexico as far back as the 1700s and along Florida's Gulf Coast since the 1840s. While red tides and other algal blooms occur worldwide,

1. brevisis found almost exclusively in the Gulf of Mexico but has been found on the east coast of Florida and off the coast of North Carolina.

How long does a red tide last?

Red tide blooms can last days, weeks or months, and can also change daily due to wind conditions. Onshore winds and water movements normally bring it near the shore and offshore winds drive it out to sea.

Is red tide predictable?

Although the occurrence of a red tide cannot be predicted, scientists can forecast its movement using wind and water current data once a bloom is located. Red tide movement and concentration are important because the effects of a red tide, such as human respiratory irritation, depend on these factors. The information provided by forecasting and monitoring allows people to make healthy and informed decisions regarding beach-going activities.

Is it safe to swim in water affected by red tide?

While people may swim in red tide, some individuals may experience skin irritation and burning eyes. If your skin is easily irritated, avoid red tide water. If you experience irritation, get out of the ocean and thoroughly wash off with fresh water.

Can red tide affect me when I am not on the beach?

It is possible that people in coastal areas in close proximity to the shoreline may experience varying degrees of eye, nose, and throat irritation. When a person leaves an area with red tide, symptoms usually go away. If symptoms persist, please seek medical attention.

Are there people who are more sensitive to the toxins caused by red tide?

People with respiratory problems (like asthma or bronchitis) should avoid red tide areas, especially when winds are blowing on shore. If you go to the beach and have one of these conditions, a short-acting inhaler usually helps. If you have symptoms, leave the beach and seek air conditioning (A/C). If symptoms persist, please seek medical attention.

What can I do to lessen the effects of red tide?

People get relief from respiratory symptoms by being in air conditioned spaces. This is also true when driving: keep your car windows up and the A/C or heat on. For people without asthma or any other chronic respiratory problems, over-the-counter antihistamines may relieve symptoms. People with chronic lung ailments should be especially vigilant about taking prescribed medications daily. Always seek medical care if your symptoms worsen.

Can red tide affect pets?

Just like people, pets may be affected by red tide. If you live close to the beach, consider bringing outdoor pets inside during a bloom to prevent respiratory irritation. If you are at the beach with your pets, do not allow them to play with dead fish or foam that may accumulate on the beach during or after a red tide.

Useful Facts and Tips about Red Tide Reference Card (2 MB PDF)

More information on K.Brevis

Charlotte County Beach Conditionsor call 1-941-BEACHES (Press 4 for Charlotte County conditions)

Health related information or to report illness from exposure to red tide: call 24/7 toll free Florida Poison Control at 1-800-222-1222.